matplotlib-devel Mailing List for matplotlib

Clang will soon start emitting warnings for mismatch uses of new and
delete. In testing this upcoming feature of Clang, I found a
mismatched new/delete pair in matplotlib. I've applied the following
patch in my local tree, but I see that the problem still exists in
trunk.
The problem here is that the constructor for
ExtensionClassMethodsTable() is allocating an array of
m_methods_table, so it should be deallocated with delete[].
If this is OK for trunk, could someone apply this patch, please?
Thanks. Diego.
--- a/lib/matplotlib/src/CXX/Python2/ExtensionType.hxx
+++ b/lib/matplotlib/src/CXX/Python2/ExtensionType.hxx
@@ -125,7 +125,7 @@ namespace Py
 ~ExtensionClassMethodsTable()
 {
- delete m_methods_table;
+ delete[] m_methods_table;
 }
 // check that all methods added are unique

You could start up a Pull Request describing a MEP that would outline how
traitlets would be used. The discussion can go on there to flesh out the
concepts and the guidance documentation. Once that is agreed upon, that PR
would get merged, and we can then start up a new PR actually implementing
the MEP.
On Thu, May 14, 2015 at 3:03 AM, Brian Granger <ell...@gm...> wrote:
> Great, that is exciting. What do you think is the best way forward? Should
> I open an issue on the matplotlib repo about this? Would there be interest
> in doing a Google+ hangout about this at some point?
>
> On Wed, May 13, 2015 at 11:57 PM, Eric Firing <ef...@ha...> wrote:
>
>> On 2015年05月13日 7:45 PM, Brian Granger wrote:
>>
>>> We (ipython/jupyter) have been talking some more about integrating
>>> matplotlilb in deeper ways with the interactive widgets framework. That
>>> only thing that would be required to make this *trivial* is having a
>>> traitlet's based API for matplotlib. I have even started to look at
>>> wrapping the existing mpl OO API using traitlets to start to explore
>>> this. Once this was done, it would be quite easy to autogenerate UIs for
>>> any aspect of Matplotlib.
>>>
>>> Now that traitlets is a standalone pure python package:
>>>
>>> https://github.com/ipython/traitlets
>>>
>>> this would be much easier to pull off.
>>>
>>> If there is interest in this, we might even be able to help do some of
>>> the work. Let us know if there is enough interest to discuss this
>>> further.
>>>
>>
>> No question about it: there is more than enough interest.
>>
>> Eric
>>
>>
>>> Cheers,
>>>
>>> Brian
>>>
>>> On Wed, May 13, 2015 at 9:36 PM, Eric Firing <ef...@ha...
>>> <mailto:ef...@ha...>> wrote:
>>>
>>> On 2015年05月13日 5:47 PM, Neil Girdhar wrote:
>>> > You're right. My angle is I just want the setters and getters.
>>> Writing
>>> > set_ and get_ feels like the C++ prison I thought I had escaped :)
>>> >
>>> John Hunter once commented that if he were doing it over again he
>>> would
>>> not have put in all the set_ and get_; they were a legacy of his
>>> origins
>>> as a C++ programmer. I think he would have started with simple
>>> attributes, which would have been adequate in the early stages.
>>> Properties were very new--only introduced in Python 2.2, at the end
>>> of 2001.
>>>
>>> Eric
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across
>>> Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you Actionable
>>> Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
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>>> _______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> <mailto:Mat...@li...>
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>>
>>>
>>>
>>> --
>>> Brian E. Granger
>>> Cal Poly State University, San Luis Obispo
>>> @ellisonbg on Twitter and GitHub
>>> bgr...@ca... <mailto:bgr...@ca...> and
>>> ell...@gm... <mailto:ell...@gm...>
>>>
>>
>>
>
>
> --
> Brian E. Granger
> Cal Poly State University, San Luis Obispo
> @ellisonbg on Twitter and GitHub
> bgr...@ca... and ell...@gm...
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
>

Thanks for tracing this Tom. I was meaning to look into it but never got
round to it.
Jens
tor. 14. maj 2015 kl. 03.30 skrev Juan Nunez-Iglesias <jni...@gm...>:
> Thanks Tom! Absolutely fascinating! I was trying to grok this and
> thinking, "but what if we want 'or' to return a value that will later be
> used as a conditional, surely it should return bool?" But of course
> whatever it returns will be correctly interpreted as a bool in a
> conditional context! Delayed/lazy bool casting, in a sense. Very clever
> indeed.
>
> There's quite a few places where this would make my code quite a bit
> cleaner! =)
>
> Thanks again!
>
> Juan.
>
> On Thu, May 14, 2015 at 12:21 PM, Thomas Caswell <tca...@gm...>
> wrote:
>
>> The `a or b` syntax evaluates if a is 'trueish' and if so returns a if
>> not returns b so `c = None or {}` -> c == {} but `c = {'a': 1} or {}` -> c
>> == {'a': 1}
>>
>> See
>> https://docs.python.org/3.5/reference/expressions.html#grammar-token-or_test
>> for the docs on or. and works almost the same, but returns a if a is False
>> and b in a is True.
>>
>> In the grammar for calls it should be looking for thing like "'**'
>> expression" which means in the parsing anything that is part of the
>> expression gets evaluated before the unpacking of the mapping. If you
>> chase far enough back in the grammar an 'or_test' is an 'expression' (I may
>> be butchering the terminology here, only just learned how lexing/parsing
>> works a few weeks ago) so it should be fully evaluated before trying to
>> unpack.
>>
>> See https://docs.python.org/3.5/reference/expressions.html#calls for the
>> official docs.
>>
>> I suspect the source of this bug is that the grammar is getting
>> rearranged a bit to allow for things like d = {**other_dict, 'x':6} and b
>> = (*a, *c) to work as expected and something did not get changed quite
>> right.
>>
>> Tom
>>
>> On Wed, May 13, 2015 at 8:33 PM Juan Nunez-Iglesias <jni...@gm...>
>> wrote:
>>
>>> Fascinating! Can you "unpack" (heh) that error for us mere mortals? In
>>> particular:
>>>
>>> - never seen that "or" syntax before... Is it coercing both expressions
>>> as bool, or is it evaluating to left if bool(left) evaluates to True, else
>>> to right?
>>> - Why do you expect the second expression to work? Is ** supposed to
>>> have lower preference than "or"? (Which seems weird to me.)
>>>
>>> Thanks!
>>>
>>> Juan.
>>>
>>> On Thu, May 14, 2015 at 5:08 AM, Thomas Caswell <tca...@gm...>
>>> wrote:
>>>
>>>>
>>>> The failures on python nightly are currently due to a bug in python (
>>>> http://bugs.python.org/issue24176)
>>>>
>>>> Tom
>>>>
>>>>
>>>> ------------------------------------------------------------------------------
>>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>>> Widest out-of-the-box monitoring support with 50+ applications
>>>> Performance metrics, stats and reports that give you Actionable Insights
>>>> Deep dive visibility with transaction tracing using APM Insight.
>>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>>> _______________________________________________
>>>> Matplotlib-devel mailing list
>>>> Mat...@li...
>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>>
>>>>
>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you Actionable Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>> _______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>

Great, that is exciting. What do you think is the best way forward? Should
I open an issue on the matplotlib repo about this? Would there be interest
in doing a Google+ hangout about this at some point?
On Wed, May 13, 2015 at 11:57 PM, Eric Firing <ef...@ha...> wrote:
> On 2015年05月13日 7:45 PM, Brian Granger wrote:
>
>> We (ipython/jupyter) have been talking some more about integrating
>> matplotlilb in deeper ways with the interactive widgets framework. That
>> only thing that would be required to make this *trivial* is having a
>> traitlet's based API for matplotlib. I have even started to look at
>> wrapping the existing mpl OO API using traitlets to start to explore
>> this. Once this was done, it would be quite easy to autogenerate UIs for
>> any aspect of Matplotlib.
>>
>> Now that traitlets is a standalone pure python package:
>>
>> https://github.com/ipython/traitlets
>>
>> this would be much easier to pull off.
>>
>> If there is interest in this, we might even be able to help do some of
>> the work. Let us know if there is enough interest to discuss this further.
>>
>
> No question about it: there is more than enough interest.
>
> Eric
>
>
>> Cheers,
>>
>> Brian
>>
>> On Wed, May 13, 2015 at 9:36 PM, Eric Firing <ef...@ha...
>> <mailto:ef...@ha...>> wrote:
>>
>> On 2015年05月13日 5:47 PM, Neil Girdhar wrote:
>> > You're right. My angle is I just want the setters and getters.
>> Writing
>> > set_ and get_ feels like the C++ prison I thought I had escaped :)
>> >
>> John Hunter once commented that if he were doing it over again he
>> would
>> not have put in all the set_ and get_; they were a legacy of his
>> origins
>> as a C++ programmer. I think he would have started with simple
>> attributes, which would have been adequate in the early stages.
>> Properties were very new--only introduced in Python 2.2, at the end
>> of 2001.
>>
>> Eric
>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across
>> Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable
>> Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> <mailto:Mat...@li...>
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>
>>
>>
>> --
>> Brian E. Granger
>> Cal Poly State University, San Luis Obispo
>> @ellisonbg on Twitter and GitHub
>> bgr...@ca... <mailto:bgr...@ca...> and
>> ell...@gm... <mailto:ell...@gm...>
>>
>
>
-- 
Brian E. Granger
Cal Poly State University, San Luis Obispo
@ellisonbg on Twitter and GitHub
bgr...@ca... and ell...@gm...

On 2015年05月13日 7:45 PM, Brian Granger wrote:
> We (ipython/jupyter) have been talking some more about integrating
> matplotlilb in deeper ways with the interactive widgets framework. That
> only thing that would be required to make this *trivial* is having a
> traitlet's based API for matplotlib. I have even started to look at
> wrapping the existing mpl OO API using traitlets to start to explore
> this. Once this was done, it would be quite easy to autogenerate UIs for
> any aspect of Matplotlib.
>
> Now that traitlets is a standalone pure python package:
>
> https://github.com/ipython/traitlets
>
> this would be much easier to pull off.
>
> If there is interest in this, we might even be able to help do some of
> the work. Let us know if there is enough interest to discuss this further.
No question about it: there is more than enough interest.
Eric
>
> Cheers,
>
> Brian
>
> On Wed, May 13, 2015 at 9:36 PM, Eric Firing <ef...@ha...
> <mailto:ef...@ha...>> wrote:
>
> On 2015年05月13日 5:47 PM, Neil Girdhar wrote:
> > You're right. My angle is I just want the setters and getters. Writing
> > set_ and get_ feels like the C++ prison I thought I had escaped :)
> >
> John Hunter once commented that if he were doing it over again he would
> not have put in all the set_ and get_; they were a legacy of his origins
> as a C++ programmer. I think he would have started with simple
> attributes, which would have been adequate in the early stages.
> Properties were very new--only introduced in Python 2.2, at the end
> of 2001.
>
> Eric
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> <mailto:Mat...@li...>
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
>
>
>
> --
> Brian E. Granger
> Cal Poly State University, San Luis Obispo
> @ellisonbg on Twitter and GitHub
> bgr...@ca... <mailto:bgr...@ca...> and
> ell...@gm... <mailto:ell...@gm...>

I should note that *all* of ipython is based on traitlets, so by now it is
very stable, battle tested (also actively developed). For base layers like
this, I think that is important.
On Wed, May 13, 2015 at 11:27 PM, Neil Girdhar <mis...@gm...>
wrote:
> This is very exciting! traitlets looks really nice. (Imho better than
> params from my cursory look.)
>
> On Thu, May 14, 2015 at 1:45 AM, Brian Granger <ell...@gm...>
> wrote:
>
>> We (ipython/jupyter) have been talking some more about integrating
>> matplotlilb in deeper ways with the interactive widgets framework. That
>> only thing that would be required to make this *trivial* is having a
>> traitlet's based API for matplotlib. I have even started to look at
>> wrapping the existing mpl OO API using traitlets to start to explore this.
>> Once this was done, it would be quite easy to autogenerate UIs for any
>> aspect of Matplotlib.
>>
>> Now that traitlets is a standalone pure python package:
>>
>> https://github.com/ipython/traitlets
>>
>> this would be much easier to pull off.
>>
>> If there is interest in this, we might even be able to help do some of
>> the work. Let us know if there is enough interest to discuss this further.
>>
>> Cheers,
>>
>> Brian
>>
>> On Wed, May 13, 2015 at 9:36 PM, Eric Firing <ef...@ha...> wrote:
>>
>>> On 2015年05月13日 5:47 PM, Neil Girdhar wrote:
>>> > You're right. My angle is I just want the setters and getters.
>>> Writing
>>> > set_ and get_ feels like the C++ prison I thought I had escaped :)
>>> >
>>> John Hunter once commented that if he were doing it over again he would
>>> not have put in all the set_ and get_; they were a legacy of his origins
>>> as a C++ programmer. I think he would have started with simple
>>> attributes, which would have been adequate in the early stages.
>>> Properties were very new--only introduced in Python 2.2, at the end of
>>> 2001.
>>>
>>> Eric
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you Actionable Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>> _______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>
>>
>>
>> --
>> Brian E. Granger
>> Cal Poly State University, San Luis Obispo
>> @ellisonbg on Twitter and GitHub
>> bgr...@ca... and ell...@gm...
>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>
>
-- 
Brian E. Granger
Cal Poly State University, San Luis Obispo
@ellisonbg on Twitter and GitHub
bgr...@ca... and ell...@gm...

This is very exciting! traitlets looks really nice. (Imho better than
params from my cursory look.)
On Thu, May 14, 2015 at 1:45 AM, Brian Granger <ell...@gm...> wrote:
> We (ipython/jupyter) have been talking some more about integrating
> matplotlilb in deeper ways with the interactive widgets framework. That
> only thing that would be required to make this *trivial* is having a
> traitlet's based API for matplotlib. I have even started to look at
> wrapping the existing mpl OO API using traitlets to start to explore this.
> Once this was done, it would be quite easy to autogenerate UIs for any
> aspect of Matplotlib.
>
> Now that traitlets is a standalone pure python package:
>
> https://github.com/ipython/traitlets
>
> this would be much easier to pull off.
>
> If there is interest in this, we might even be able to help do some of the
> work. Let us know if there is enough interest to discuss this further.
>
> Cheers,
>
> Brian
>
> On Wed, May 13, 2015 at 9:36 PM, Eric Firing <ef...@ha...> wrote:
>
>> On 2015年05月13日 5:47 PM, Neil Girdhar wrote:
>> > You're right. My angle is I just want the setters and getters. Writing
>> > set_ and get_ feels like the C++ prison I thought I had escaped :)
>> >
>> John Hunter once commented that if he were doing it over again he would
>> not have put in all the set_ and get_; they were a legacy of his origins
>> as a C++ programmer. I think he would have started with simple
>> attributes, which would have been adequate in the early stages.
>> Properties were very new--only introduced in Python 2.2, at the end of
>> 2001.
>>
>> Eric
>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>
>
>
> --
> Brian E. Granger
> Cal Poly State University, San Luis Obispo
> @ellisonbg on Twitter and GitHub
> bgr...@ca... and ell...@gm...
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
>

We (ipython/jupyter) have been talking some more about integrating
matplotlilb in deeper ways with the interactive widgets framework. That
only thing that would be required to make this *trivial* is having a
traitlet's based API for matplotlib. I have even started to look at
wrapping the existing mpl OO API using traitlets to start to explore this.
Once this was done, it would be quite easy to autogenerate UIs for any
aspect of Matplotlib.
Now that traitlets is a standalone pure python package:
https://github.com/ipython/traitlets
this would be much easier to pull off.
If there is interest in this, we might even be able to help do some of the
work. Let us know if there is enough interest to discuss this further.
Cheers,
Brian
On Wed, May 13, 2015 at 9:36 PM, Eric Firing <ef...@ha...> wrote:
> On 2015年05月13日 5:47 PM, Neil Girdhar wrote:
> > You're right. My angle is I just want the setters and getters. Writing
> > set_ and get_ feels like the C++ prison I thought I had escaped :)
> >
> John Hunter once commented that if he were doing it over again he would
> not have put in all the set_ and get_; they were a legacy of his origins
> as a C++ programmer. I think he would have started with simple
> attributes, which would have been adequate in the early stages.
> Properties were very new--only introduced in Python 2.2, at the end of
> 2001.
>
> Eric
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
-- 
Brian E. Granger
Cal Poly State University, San Luis Obispo
@ellisonbg on Twitter and GitHub
bgr...@ca... and ell...@gm...

On 2015年05月13日 5:47 PM, Neil Girdhar wrote:
> You're right. My angle is I just want the setters and getters. Writing
> set_ and get_ feels like the C++ prison I thought I had escaped :)
>
John Hunter once commented that if he were doing it over again he would 
not have put in all the set_ and get_; they were a legacy of his origins 
as a C++ programmer. I think he would have started with simple 
attributes, which would have been adequate in the early stages. 
Properties were very new--only introduced in Python 2.2, at the end of 2001.
Eric

You're right. My angle is I just want the setters and getters. Writing
set_ and get_ feels like the C++ prison I thought I had escaped :)
I'll keep an eye for the discussion on this topic since this is interesting
to me for other reasons as well. (I had to code something like params for
my own code).
Best,
Neil
On Wed, May 13, 2015 at 11:42 PM, Benjamin Root <ben...@ou...> wrote:
> Manpower, really. Also, there be dragons deep in that code (I'll leave it
> as an exploration task for you to figure out how aliases are done).
>
> There have been a few proposals, but they keep suffering from scope creep.
> Take a look at the MEP page.
>
> Keep in mind that reducing Lines of Code just for the sake of reducing
> lines of code isn't all that useful. The current code isn't broken, and
> there are no plans to add more properties, so it isn't much of a hinderance
> (compared to other aspects of the codebase). But a proposal that makes
> validation and style-handling (or some such) would be valuable.
>
> Cheers!
> Ben Root
> On May 13, 2015 11:06 PM, "Neil Girdhar" <mis...@gm...> wrote:
>
>> I don't want to ruffle any feathers, and I'm sure this comes up all the
>> time, but I'm wondering why don't we have a decorator on classes that
>> generates all of the boilerplate methods?
>>
>> For example:
>>
>> @generate_boilerplate([('linestyle', 'ls'), ...]
>> class Patch(...):
>>
>> would generate
>>
>> get_ls, set_ls to point to get_linestyle and set_linestyle and their
>> docstrings
>>
>> and would generate
>>
>> linestyle = property(get_linestyle, set_linestyle) and their docstring.
>>
>> This would reduce a lot of boilerplate code and provide the modern
>> getters and setters. In the future, a user could enable an option to
>> disable the old style interface and remove it from 'dir', etc.
>>
>> What's the reason for not providing the "new"-style getters and setters?
>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>

Manpower, really. Also, there be dragons deep in that code (I'll leave it
as an exploration task for you to figure out how aliases are done).
There have been a few proposals, but they keep suffering from scope creep.
Take a look at the MEP page.
Keep in mind that reducing Lines of Code just for the sake of reducing
lines of code isn't all that useful. The current code isn't broken, and
there are no plans to add more properties, so it isn't much of a hinderance
(compared to other aspects of the codebase). But a proposal that makes
validation and style-handling (or some such) would be valuable.
Cheers!
Ben Root
On May 13, 2015 11:06 PM, "Neil Girdhar" <mis...@gm...> wrote:
> I don't want to ruffle any feathers, and I'm sure this comes up all the
> time, but I'm wondering why don't we have a decorator on classes that
> generates all of the boilerplate methods?
>
> For example:
>
> @generate_boilerplate([('linestyle', 'ls'), ...]
> class Patch(...):
>
> would generate
>
> get_ls, set_ls to point to get_linestyle and set_linestyle and their
> docstrings
>
> and would generate
>
> linestyle = property(get_linestyle, set_linestyle) and their docstring.
>
> This would reduce a lot of boilerplate code and provide the modern getters
> and setters. In the future, a user could enable an option to disable the
> old style interface and remove it from 'dir', etc.
>
> What's the reason for not providing the "new"-style getters and setters?
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
>

It is my understanding that most of this code pre-dates properties and
going through and updating all of the classes is a _huge_ amount of work.
It is more a matter of time than will.
There is also a slowly simmering discussion about implementing artists in a
managed property/attribute frame work (either traitlets, param, or rolling
our own) which is related to this.
On Wed, May 13, 2015 at 11:06 PM Neil Girdhar <mis...@gm...> wrote:
> I don't want to ruffle any feathers, and I'm sure this comes up all the
> time, but I'm wondering why don't we have a decorator on classes that
> generates all of the boilerplate methods?
>
> For example:
>
> @generate_boilerplate([('linestyle', 'ls'), ...]
> class Patch(...):
>
> would generate
>
> get_ls, set_ls to point to get_linestyle and set_linestyle and their
> docstrings
>
> and would generate
>
> linestyle = property(get_linestyle, set_linestyle) and their docstring.
>
> This would reduce a lot of boilerplate code and provide the modern getters
> and setters. In the future, a user could enable an option to disable the
> old style interface and remove it from 'dir', etc.
>
> What's the reason for not providing the "new"-style getters and setters?
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>

Sorry, I may have been being a bit dramatic
In mpl.patches: Arrow, FancyArrow, YAArrow, FancyArrowPatch,
ConnectionPatch + annotation related artists + some classes in axisartist
which now that I look at them are not really general purpose arrow tools.
I had not been counting quiver (or barbs) or sankey.
Neil: Those are all great questions! Much of the arrow related code was
written by Joe-Joon Lee who (by having read a good deal of his code) has a
habit of writing very power but very opaque python.
I believe that the line join style is controlled by `joinstyle` on the
graphics context and it is up to the backends to implement that correctly.
Tom
On Wed, May 13, 2015 at 10:58 PM Neil Girdhar <mis...@gm...> wrote:
> Okay, I'm looking at this in more detail and there may be some design
> concerns:
>
> The arrow placement is decided without asking the arrow any questions,
> such as its bounding box. Instead, the arrow should return a bounding box
> and then the line should retreat until the bounding box no longer
> intersects the target node. Then the arrow should be placed. This doesn't
> matter so much when you have a simple arrow like this: ---->, but it's a
> big deal when you have an arrow like ----| . In this case, the sides of
> the arrow risk intersecting with the target node.
>
> I'm not keen on implementing every arrow three times: <-, ->, <->. This
> really should be handled by the code placing the arrows for many reasons:
> 1. It should also be possible to have a different arrowhead at either end
> of the line.
> 2. It should be possible to stack the arrows, for example having two heads
> one after another (to represent two kinds of relationships). This is
> another reason to be able to ask the arrowhead its length and so on.
>
> I don't understand the "monolithic" keyword. How can the arrow draw the
> line as well when it doesn't know the line style, color and so on?
>
> I think I like the design of the transmute function. I'm curious:
> ultimately, where does the mutation_size come from? Is it a global scale
> applied to the figure, or is it based on the linewidth, or?
>
> When you emit a set of lines, how are they joined? If I draw a line
> having linewidth 0.1 from the origin to (1, 0), and back to (0, 0.5), what
> happens at the tip? Are two rectangles drawn (each having width 0.1, but
> oriented differently)? Is a bevel created? A miter? Or is the tip
> rounded? Can this be controlled? See page 166 of the manual I sent
> earlier (search for tikz/line join).
>
> Best,
>
> Neil
>
> On Wed, May 13, 2015 at 10:14 PM, Neil Girdhar <mis...@gm...>
> wrote:
>
>> Thanks, it works!
>>
>> I needed to add:
>>
>> import matplotlib.patches
>>
>> to one file and
>>
>> plt.show()
>>
>> to the other.
>>
>> Any word on the locations in the code of the seven arrow drawing methods?
>>
>> I've located the arrow drawing code in tikz, and so I can start porting
>> it over. I'm curious, do we know the linewidth of the edge being decorated
>> by the arrow? To make arrows scale nicely, most of the arrow dimensions
>> are given in two pieces: an absolute value (in points for example) and a
>> line width factor. The dimension is the absolute value plus the line width
>> factor times the line width. The TikZ manual explains: "This makes it easy
>> to vary the size of an arrow tip in accordance with the line width –
>> usually a very good idea since thicker lines will need thicker arrow tips."
>>
>> Best,
>>
>> Neil
>>
>> On Wed, May 13, 2015 at 10:07 PM, Benjamin Reedlunn <bre...@gm...>
>> wrote:
>>
>>> Neil,
>>>
>>> I have attached code to draw the arrowhead.
>>>
>>> -Ben
>>>
>>>
>>>
>>> On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...> wrote:
>>>
>>> Do you have the code that you used to draw the arrowhead? I'm up to
>>> date now on the development workflow (
>>> http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm
>>> ready to start working.
>>>
>>> Thanks,
>>>
>>> Neil
>>>
>>> On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
>>> wrote:
>>>
>>>> Yes, I fully agree that we need to unify the many different ways to
>>>> draw arrows.
>>>>
>>>> Neil, in case an example would be helpful for you, I have attached a
>>>> module that includes a custom arrowhead class. The arrowhead class works
>>>> with the with the ax.annotate() method. (I like the annotate method
>>>> because it allows me to easily mix and match coordinate systems for arrow
>>>> placement.) As you can see in the attached pdf, the custom arrowhead
>>>> doesn't include fancy Bezier curves, but that could be added.
>>>>
>>>> -Ben
>>>>
>>>>
>>>>
>>>> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>>>>
>>>> The other thing that should be done is to unify the (I think 7?!?)
>>>> unique ways to draw arrows in mpl.
>>>>
>>>> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
>>>> wrote:
>>>>
>>>>> Yes, I just noticed that as well. That's how the tikz pgf code looks
>>>>> (a sequence of line_to and curve_to commands and so on) so it should be
>>>>> easy to port over the various shapes.
>>>>>
>>>>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...>
>>>>> wrote:
>>>>>
>>>>>> On 2015年05月13日 10:12 AM, Neil Girdhar wrote:
>>>>>>
>>>>>>> If you want to make arrowheads look at all decent, they really need
>>>>>>> to
>>>>>>> be enclosed in Bezier curves. See the diagram here:
>>>>>>>
>>>>>>
>>>>>> Mpl paths support Bezier curves.
>>>>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>>>>
>>>>>>> The first two look like garbage. The last one is the only one that
>>>>>>> looks good imho.
>>>>>>>
>>>>>>
>>>>>> That depends on the application, and the observer.
>>>>>
>>>>>
>>>>> Sure, but I may as well port them all of the tikz arrowheads over
>>>>> since most of the work would be figuring out how to do it.
>>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>> Eric
>>>>>>
>>>>>>
>>>>>>> Best,
>>>>>>>
>>>>>>> Neil
>>>>>>>
>>>>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>>>>> <mailto:ef...@ha...>> wrote:
>>>>>>>
>>>>>>> On 2015年05月13日 9:36 AM, Neil Girdhar wrote:
>>>>>>>
>>>>>>> I don't know matplotlib well enough (yet) to know what the
>>>>>>> change would
>>>>>>> consist of.
>>>>>>>
>>>>>>> I suggest you take a look at the beautiful tikz manual:
>>>>>>> http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>>>>
>>>>>>>
>>>>>>> Very helpful, thank you.
>>>>>>>
>>>>>>>
>>>>>>> The arrows.meta on page 201–212 are really well-designed and
>>>>>>> beautiful.
>>>>>>>
>>>>>>> Compare this with matplotlib's custom arrows:
>>>>>>>
>>>>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>>>>
>>>>>>> How do I make tikz's arrowheads available for all backends?
>>>>>>>
>>>>>>>
>>>>>>> My guess offhand is that this is a matter of using the mpl API.
>>>>>>> I
>>>>>>> don't think we would want to add all of these types and options
>>>>>>> to
>>>>>>> the mpl core; but a toolkit might be ideal for this. The mpl
>>>>>>> API,
>>>>>>> which generates the same results for all backends, is quite
>>>>>>> complete
>>>>>>> and flexible. Things like arrowheads are Patch objects, and you
>>>>>>> can
>>>>>>> specify any path you want. The main trick is figuring out how to
>>>>>>> handle transforms--what kind of coordinates should the path be
>>>>>>> specifying? How should things scale as a figure is reshaped and
>>>>>>> resized?
>>>>>>>
>>>>>>> For many of these types you could also use mpl Line2D objects,
>>>>>>> for
>>>>>>> which several properties including cap style can be specified.
>>>>>>> Not
>>>>>>> all of the TikZ options would be available, but perhaps enough.
>>>>>>>
>>>>>>> Eric
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>> ------------------------------------------------------------------------------
>>>>> One dashboard for servers and applications across
>>>>> Physical-Virtual-Cloud
>>>>> Widest out-of-the-box monitoring support with 50+ applications
>>>>> Performance metrics, stats and reports that give you Actionable
>>>>> Insights
>>>>> Deep dive visibility with transaction tracing using APM Insight.
>>>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>>>> _______________________________________________
>>>>> Matplotlib-devel mailing list
>>>>> Mat...@li...
>>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>>>
>>>>
>>>> ------------------------------------------------------------------------------
>>>> One dashboard for servers and applications across
>>>> Physical-Virtual-Cloud
>>>> Widest out-of-the-box monitoring support with 50+ applications
>>>> Performance metrics, stats and reports that give you Actionable Insights
>>>> Deep dive visibility with transaction tracing using APM Insight.
>>>>
>>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>>>> Matplotlib-devel mailing list
>>>> Mat...@li...
>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>

I don't want to ruffle any feathers, and I'm sure this comes up all the
time, but I'm wondering why don't we have a decorator on classes that
generates all of the boilerplate methods?
For example:
@generate_boilerplate([('linestyle', 'ls'), ...]
class Patch(...):
would generate
get_ls, set_ls to point to get_linestyle and set_linestyle and their
docstrings
and would generate
linestyle = property(get_linestyle, set_linestyle) and their docstring.
This would reduce a lot of boilerplate code and provide the modern getters
and setters. In the future, a user could enable an option to disable the
old style interface and remove it from 'dir', etc.
What's the reason for not providing the "new"-style getters and setters?

Okay, I'm looking at this in more detail and there may be some design
concerns:
The arrow placement is decided without asking the arrow any questions, such
as its bounding box. Instead, the arrow should return a bounding box and
then the line should retreat until the bounding box no longer intersects
the target node. Then the arrow should be placed. This doesn't matter so
much when you have a simple arrow like this: ---->, but it's a big deal
when you have an arrow like ----| . In this case, the sides of the arrow
risk intersecting with the target node.
I'm not keen on implementing every arrow three times: <-, ->, <->. This
really should be handled by the code placing the arrows for many reasons:
1. It should also be possible to have a different arrowhead at either end
of the line.
2. It should be possible to stack the arrows, for example having two heads
one after another (to represent two kinds of relationships). This is
another reason to be able to ask the arrowhead its length and so on.
I don't understand the "monolithic" keyword. How can the arrow draw the
line as well when it doesn't know the line style, color and so on?
I think I like the design of the transmute function. I'm curious:
ultimately, where does the mutation_size come from? Is it a global scale
applied to the figure, or is it based on the linewidth, or?
When you emit a set of lines, how are they joined? If I draw a line having
linewidth 0.1 from the origin to (1, 0), and back to (0, 0.5), what happens
at the tip? Are two rectangles drawn (each having width 0.1, but oriented
differently)? Is a bevel created? A miter? Or is the tip rounded? Can
this be controlled? See page 166 of the manual I sent earlier (search for
tikz/line join).
Best,
Neil
On Wed, May 13, 2015 at 10:14 PM, Neil Girdhar <mis...@gm...>
wrote:
> Thanks, it works!
>
> I needed to add:
>
> import matplotlib.patches
>
> to one file and
>
> plt.show()
>
> to the other.
>
> Any word on the locations in the code of the seven arrow drawing methods?
>
> I've located the arrow drawing code in tikz, and so I can start porting it
> over. I'm curious, do we know the linewidth of the edge being decorated by
> the arrow? To make arrows scale nicely, most of the arrow dimensions are
> given in two pieces: an absolute value (in points for example) and a line
> width factor. The dimension is the absolute value plus the line width
> factor times the line width. The TikZ manual explains: "This makes it easy
> to vary the size of an arrow tip in accordance with the line width –
> usually a very good idea since thicker lines will need thicker arrow tips."
>
> Best,
>
> Neil
>
> On Wed, May 13, 2015 at 10:07 PM, Benjamin Reedlunn <bre...@gm...>
> wrote:
>
>> Neil,
>>
>> I have attached code to draw the arrowhead.
>>
>> -Ben
>>
>>
>>
>> On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...> wrote:
>>
>> Do you have the code that you used to draw the arrowhead? I'm up to date
>> now on the development workflow (
>> http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm
>> ready to start working.
>>
>> Thanks,
>>
>> Neil
>>
>> On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
>> wrote:
>>
>>> Yes, I fully agree that we need to unify the many different ways to draw
>>> arrows.
>>>
>>> Neil, in case an example would be helpful for you, I have attached a
>>> module that includes a custom arrowhead class. The arrowhead class works
>>> with the with the ax.annotate() method. (I like the annotate method
>>> because it allows me to easily mix and match coordinate systems for arrow
>>> placement.) As you can see in the attached pdf, the custom arrowhead
>>> doesn't include fancy Bezier curves, but that could be added.
>>>
>>> -Ben
>>>
>>>
>>>
>>> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>>>
>>> The other thing that should be done is to unify the (I think 7?!?)
>>> unique ways to draw arrows in mpl.
>>>
>>> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
>>> wrote:
>>>
>>>> Yes, I just noticed that as well. That's how the tikz pgf code looks
>>>> (a sequence of line_to and curve_to commands and so on) so it should be
>>>> easy to port over the various shapes.
>>>>
>>>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...>
>>>> wrote:
>>>>
>>>>> On 2015年05月13日 10:12 AM, Neil Girdhar wrote:
>>>>>
>>>>>> If you want to make arrowheads look at all decent, they really need to
>>>>>> be enclosed in Bezier curves. See the diagram here:
>>>>>>
>>>>>
>>>>> Mpl paths support Bezier curves.
>>>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>>>
>>>>>
>>>>>>
>>>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>>>
>>>>>> The first two look like garbage. The last one is the only one that
>>>>>> looks good imho.
>>>>>>
>>>>>
>>>>> That depends on the application, and the observer.
>>>>
>>>>
>>>> Sure, but I may as well port them all of the tikz arrowheads over since
>>>> most of the work would be figuring out how to do it.
>>>>
>>>>
>>>>>
>>>>>
>>>>> Eric
>>>>>
>>>>>
>>>>>> Best,
>>>>>>
>>>>>> Neil
>>>>>>
>>>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>>>> <mailto:ef...@ha...>> wrote:
>>>>>>
>>>>>> On 2015年05月13日 9:36 AM, Neil Girdhar wrote:
>>>>>>
>>>>>> I don't know matplotlib well enough (yet) to know what the
>>>>>> change would
>>>>>> consist of.
>>>>>>
>>>>>> I suggest you take a look at the beautiful tikz manual:
>>>>>> http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>>>
>>>>>>
>>>>>> Very helpful, thank you.
>>>>>>
>>>>>>
>>>>>> The arrows.meta on page 201–212 are really well-designed and
>>>>>> beautiful.
>>>>>>
>>>>>> Compare this with matplotlib's custom arrows:
>>>>>>
>>>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>>>
>>>>>> How do I make tikz's arrowheads available for all backends?
>>>>>>
>>>>>>
>>>>>> My guess offhand is that this is a matter of using the mpl API. I
>>>>>> don't think we would want to add all of these types and options to
>>>>>> the mpl core; but a toolkit might be ideal for this. The mpl API,
>>>>>> which generates the same results for all backends, is quite
>>>>>> complete
>>>>>> and flexible. Things like arrowheads are Patch objects, and you
>>>>>> can
>>>>>> specify any path you want. The main trick is figuring out how to
>>>>>> handle transforms--what kind of coordinates should the path be
>>>>>> specifying? How should things scale as a figure is reshaped and
>>>>>> resized?
>>>>>>
>>>>>> For many of these types you could also use mpl Line2D objects, for
>>>>>> which several properties including cap style can be specified.
>>>>>> Not
>>>>>> all of the TikZ options would be available, but perhaps enough.
>>>>>>
>>>>>> Eric
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>> ------------------------------------------------------------------------------
>>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>>> Widest out-of-the-box monitoring support with 50+ applications
>>>> Performance metrics, stats and reports that give you Actionable Insights
>>>> Deep dive visibility with transaction tracing using APM Insight.
>>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>>> _______________________________________________
>>>> Matplotlib-devel mailing list
>>>> Mat...@li...
>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>>
>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you Actionable Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
>>>
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>>
>>>
>>>
>>
>>
>>
>

On 2015年05月13日 4:14 PM, Neil Girdhar wrote:
> Thanks, it works!
>
> I needed to add:
>
> import matplotlib.patches
>
> to one file and
>
> plt.show()
>
> to the other.
>
> Any word on the locations in the code of the seven arrow drawing methods?
I'm not sure how to get to a count of seven. One of them is in the 
quiver module, but it is very different from the others, and at least 
for now I suggest you ignore it. Probably everything else is in the 
patches module, and much of it is called in the text module. Maybe 
Thomas is counting the text module usage. Ah, yes, and then there is the 
sankey module.
See also https://github.com/matplotlib/matplotlib/pull/4178.
Eric
>
> I've located the arrow drawing code in tikz, and so I can start porting
> it over. I'm curious, do we know the linewidth of the edge being
> decorated by the arrow? To make arrows scale nicely, most of the arrow
> dimensions are given in two pieces: an absolute value (in points for
> example) and a line width factor. The dimension is the absolute value
> plus the line width factor times the line width. The TikZ manual
> explains: "This makes it easy to vary the size of an arrow tip in
> accordance with the line width – usually a very good idea since thicker
> lines will need thicker arrow tips."
>
> Best,
>
> Neil
>
> On Wed, May 13, 2015 at 10:07 PM, Benjamin Reedlunn <bre...@gm...
> <mailto:bre...@gm...>> wrote:
>
> Neil,
>
> I have attached code to draw the arrowhead.
>
> -Ben
>
>
>
> On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...
> <mailto:mis...@gm...>> wrote:
>
>> Do you have the code that you used to draw the arrowhead? I'm up
>> to date now on the development workflow
>> (http://matplotlib.org/devel/gitwash/development_workflow.html),
>> so I'm ready to start working.
>>
>> Thanks,
>>
>> Neil
>>
>> On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn
>> <bre...@gm... <mailto:bre...@gm...>> wrote:
>>
>> Yes, I fully agree that we need to unify the many different
>> ways to draw arrows.
>>
>> Neil, in case an example would be helpful for you, I have
>> attached a module that includes a custom arrowhead class. The
>> arrowhead class works with the with the ax.annotate() method.
>> (I like the annotate method because it allows me to easily
>> mix and match coordinate systems for arrow placement.) As you
>> can see in the attached pdf, the custom arrowhead doesn't
>> include fancy Bezier curves, but that could be added.
>>
>> -Ben
>>
>>
>>
>> On May 13, 2015, at 2:54 PM, Thomas Caswell
>> <tca...@gm... <mailto:tca...@gm...>> wrote:
>>
>>> The other thing that should be done is to unify the (I think
>>> 7?!?) unique ways to draw arrows in mpl.
>>>
>>> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar
>>> <mis...@gm... <mailto:mis...@gm...>> wrote:
>>>
>>> Yes, I just noticed that as well. That's how the tikz
>>> pgf code looks (a sequence of line_to and curve_to
>>> commands and so on) so it should be easy to port over the
>>> various shapes.
>>>
>>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing
>>> <ef...@ha... <mailto:ef...@ha...>> wrote:
>>>
>>> On 2015年05月13日 10:12 AM, Neil Girdhar wrote:
>>>
>>> If you want to make arrowheads look at all
>>> decent, they really need to
>>> be enclosed in Bezier curves. See the diagram here:
>>>
>>>
>>> Mpl paths support Bezier curves.
>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>
>>>
>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>
>>> The first two look like garbage. The last one is
>>> the only one that
>>> looks good imho.
>>>
>>>
>>> That depends on the application, and the observer.
>>>
>>>
>>> Sure, but I may as well port them all of the tikz
>>> arrowheads over since most of the work would be figuring
>>> out how to do it.
>>>
>>>
>>>
>>> Eric
>>>
>>>
>>> Best,
>>>
>>> Neil
>>>
>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing
>>> <ef...@ha... <mailto:ef...@ha...>
>>> <mailto:ef...@ha...
>>> <mailto:ef...@ha...>>> wrote:
>>>
>>> On 2015年05月13日 9:36 AM, Neil Girdhar wrote:
>>>
>>> I don't know matplotlib well enough (yet)
>>> to know what the
>>> change would
>>> consist of.
>>>
>>> I suggest you take a look at the
>>> beautiful tikz manual:
>>> http://pgf.sourceforge.net/pgf_CVS.pdf
>>>
>>>
>>> Very helpful, thank you.
>>>
>>>
>>> The arrows.meta on page 201–212 are
>>> really well-designed and
>>> beautiful.
>>>
>>> Compare this with matplotlib's custom arrows:
>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>
>>> How do I make tikz's arrowheads available
>>> for all backends?
>>>
>>>
>>> My guess offhand is that this is a matter of
>>> using the mpl API. I
>>> don't think we would want to add all of these
>>> types and options to
>>> the mpl core; but a toolkit might be ideal
>>> for this. The mpl API,
>>> which generates the same results for all
>>> backends, is quite complete
>>> and flexible. Things like arrowheads are
>>> Patch objects, and you can
>>> specify any path you want. The main trick is
>>> figuring out how to
>>> handle transforms--what kind of coordinates
>>> should the path be
>>> specifying? How should things scale as a
>>> figure is reshaped and
>>> resized?
>>>
>>> For many of these types you could also use
>>> mpl Line2D objects, for
>>> which several properties including cap style
>>> can be specified. Not
>>> all of the TikZ options would be available,
>>> but perhaps enough.
>>>
>>> Eric
>>>
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across
>>> Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+
>>> applications
>>> Performance metrics, stats and reports that give you
>>> Actionable Insights
>>> Deep dive visibility with transaction tracing using APM
>>> Insight.
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> <mailto:Mat...@li...>
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across
>>> Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you
>>> Actionable Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> <mailto:Mat...@li...>
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>
>>
>
>
>

Thanks Tom! Absolutely fascinating! I was trying to grok this and thinking,
"but what if we want 'or' to return a value that will later be used as a
conditional, surely it should return bool?" But of course whatever it
returns will be correctly interpreted as a bool in a conditional context!
Delayed/lazy bool casting, in a sense. Very clever indeed.
There's quite a few places where this would make my code quite a bit
cleaner! =)
Thanks again!
Juan.
On Thu, May 14, 2015 at 12:21 PM, Thomas Caswell <tca...@gm...> wrote:
> The `a or b` syntax evaluates if a is 'trueish' and if so returns a if not
> returns b so `c = None or {}` -> c == {} but `c = {'a': 1} or {}` -> c ==
> {'a': 1}
>
> See
> https://docs.python.org/3.5/reference/expressions.html#grammar-token-or_test
> for the docs on or. and works almost the same, but returns a if a is False
> and b in a is True.
>
> In the grammar for calls it should be looking for thing like "'**'
> expression" which means in the parsing anything that is part of the
> expression gets evaluated before the unpacking of the mapping. If you
> chase far enough back in the grammar an 'or_test' is an 'expression' (I may
> be butchering the terminology here, only just learned how lexing/parsing
> works a few weeks ago) so it should be fully evaluated before trying to
> unpack.
>
> See https://docs.python.org/3.5/reference/expressions.html#calls for the
> official docs.
>
> I suspect the source of this bug is that the grammar is getting rearranged
> a bit to allow for things like d = {**other_dict, 'x':6} and b = (*a, *c)
> to work as expected and something did not get changed quite right.
>
> Tom
>
> On Wed, May 13, 2015 at 8:33 PM Juan Nunez-Iglesias <jni...@gm...>
> wrote:
>
>> Fascinating! Can you "unpack" (heh) that error for us mere mortals? In
>> particular:
>>
>> - never seen that "or" syntax before... Is it coercing both expressions
>> as bool, or is it evaluating to left if bool(left) evaluates to True, else
>> to right?
>> - Why do you expect the second expression to work? Is ** supposed to have
>> lower preference than "or"? (Which seems weird to me.)
>>
>> Thanks!
>>
>> Juan.
>>
>> On Thu, May 14, 2015 at 5:08 AM, Thomas Caswell <tca...@gm...>
>> wrote:
>>
>>>
>>> The failures on python nightly are currently due to a bug in python (
>>> http://bugs.python.org/issue24176)
>>>
>>> Tom
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you Actionable Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>> _______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>

The `a or b` syntax evaluates if a is 'trueish' and if so returns a if not
returns b so `c = None or {}` -> c == {} but `c = {'a': 1} or {}` -> c ==
{'a': 1}
See
https://docs.python.org/3.5/reference/expressions.html#grammar-token-or_test
for the docs on or. and works almost the same, but returns a if a is False
and b in a is True.
In the grammar for calls it should be looking for thing like "'**'
expression" which means in the parsing anything that is part of the
expression gets evaluated before the unpacking of the mapping. If you
chase far enough back in the grammar an 'or_test' is an 'expression' (I may
be butchering the terminology here, only just learned how lexing/parsing
works a few weeks ago) so it should be fully evaluated before trying to
unpack.
See https://docs.python.org/3.5/reference/expressions.html#calls for the
official docs.
I suspect the source of this bug is that the grammar is getting rearranged
a bit to allow for things like d = {**other_dict, 'x':6} and b = (*a, *c)
to work as expected and something did not get changed quite right.
Tom
On Wed, May 13, 2015 at 8:33 PM Juan Nunez-Iglesias <jni...@gm...>
wrote:
> Fascinating! Can you "unpack" (heh) that error for us mere mortals? In
> particular:
>
> - never seen that "or" syntax before... Is it coercing both expressions as
> bool, or is it evaluating to left if bool(left) evaluates to True, else to
> right?
> - Why do you expect the second expression to work? Is ** supposed to have
> lower preference than "or"? (Which seems weird to me.)
>
> Thanks!
>
> Juan.
>
> On Thu, May 14, 2015 at 5:08 AM, Thomas Caswell <tca...@gm...>
> wrote:
>
>>
>> The failures on python nightly are currently due to a bug in python (
>> http://bugs.python.org/issue24176)
>>
>> Tom
>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>

Thanks, it works!
I needed to add:
import matplotlib.patches
to one file and
plt.show()
to the other.
Any word on the locations in the code of the seven arrow drawing methods?
I've located the arrow drawing code in tikz, and so I can start porting it
over. I'm curious, do we know the linewidth of the edge being decorated by
the arrow? To make arrows scale nicely, most of the arrow dimensions are
given in two pieces: an absolute value (in points for example) and a line
width factor. The dimension is the absolute value plus the line width
factor times the line width. The TikZ manual explains: "This makes it easy
to vary the size of an arrow tip in accordance with the line width –
usually a very good idea since thicker lines will need thicker arrow tips."
Best,
Neil
On Wed, May 13, 2015 at 10:07 PM, Benjamin Reedlunn <bre...@gm...>
wrote:
> Neil,
>
> I have attached code to draw the arrowhead.
>
> -Ben
>
>
>
> On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...> wrote:
>
> Do you have the code that you used to draw the arrowhead? I'm up to date
> now on the development workflow (
> http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm
> ready to start working.
>
> Thanks,
>
> Neil
>
> On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
> wrote:
>
>> Yes, I fully agree that we need to unify the many different ways to draw
>> arrows.
>>
>> Neil, in case an example would be helpful for you, I have attached a
>> module that includes a custom arrowhead class. The arrowhead class works
>> with the with the ax.annotate() method. (I like the annotate method
>> because it allows me to easily mix and match coordinate systems for arrow
>> placement.) As you can see in the attached pdf, the custom arrowhead
>> doesn't include fancy Bezier curves, but that could be added.
>>
>> -Ben
>>
>>
>>
>> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>>
>> The other thing that should be done is to unify the (I think 7?!?) unique
>> ways to draw arrows in mpl.
>>
>> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
>> wrote:
>>
>>> Yes, I just noticed that as well. That's how the tikz pgf code looks (a
>>> sequence of line_to and curve_to commands and so on) so it should be easy
>>> to port over the various shapes.
>>>
>>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
>>>
>>>> On 2015年05月13日 10:12 AM, Neil Girdhar wrote:
>>>>
>>>>> If you want to make arrowheads look at all decent, they really need to
>>>>> be enclosed in Bezier curves. See the diagram here:
>>>>>
>>>>
>>>> Mpl paths support Bezier curves.
>>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>>
>>>>
>>>>>
>>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>>
>>>>> The first two look like garbage. The last one is the only one that
>>>>> looks good imho.
>>>>>
>>>>
>>>> That depends on the application, and the observer.
>>>
>>>
>>> Sure, but I may as well port them all of the tikz arrowheads over since
>>> most of the work would be figuring out how to do it.
>>>
>>>
>>>>
>>>>
>>>> Eric
>>>>
>>>>
>>>>> Best,
>>>>>
>>>>> Neil
>>>>>
>>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>>> <mailto:ef...@ha...>> wrote:
>>>>>
>>>>> On 2015年05月13日 9:36 AM, Neil Girdhar wrote:
>>>>>
>>>>> I don't know matplotlib well enough (yet) to know what the
>>>>> change would
>>>>> consist of.
>>>>>
>>>>> I suggest you take a look at the beautiful tikz manual:
>>>>> http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>>
>>>>>
>>>>> Very helpful, thank you.
>>>>>
>>>>>
>>>>> The arrows.meta on page 201–212 are really well-designed and
>>>>> beautiful.
>>>>>
>>>>> Compare this with matplotlib's custom arrows:
>>>>>
>>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>>
>>>>> How do I make tikz's arrowheads available for all backends?
>>>>>
>>>>>
>>>>> My guess offhand is that this is a matter of using the mpl API. I
>>>>> don't think we would want to add all of these types and options to
>>>>> the mpl core; but a toolkit might be ideal for this. The mpl API,
>>>>> which generates the same results for all backends, is quite
>>>>> complete
>>>>> and flexible. Things like arrowheads are Patch objects, and you
>>>>> can
>>>>> specify any path you want. The main trick is figuring out how to
>>>>> handle transforms--what kind of coordinates should the path be
>>>>> specifying? How should things scale as a figure is reshaped and
>>>>> resized?
>>>>>
>>>>> For many of these types you could also use mpl Line2D objects, for
>>>>> which several properties including cap style can be specified. Not
>>>>> all of the TikZ options would be available, but perhaps enough.
>>>>>
>>>>> Eric
>>>>>
>>>>>
>>>>>
>>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you Actionable Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>> _______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>>
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>
>>
>>
>
>
>

Neil,
I have attached code to draw the arrowhead.
-Ben
On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...> wrote:
> Do you have the code that you used to draw the arrowhead? I'm up to date now on the development workflow (http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm ready to start working.
> 
> Thanks,
> 
> Neil
> 
> On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...> wrote:
> Yes, I fully agree that we need to unify the many different ways to draw arrows. 
> 
> Neil, in case an example would be helpful for you, I have attached a module that includes a custom arrowhead class. The arrowhead class works with the with the ax.annotate() method. (I like the annotate method because it allows me to easily mix and match coordinate systems for arrow placement.) As you can see in the attached pdf, the custom arrowhead doesn't include fancy Bezier curves, but that could be added.
> 
> -Ben
> 
> 
> 
> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
> 
>> The other thing that should be done is to unify the (I think 7?!?) unique ways to draw arrows in mpl.
>> 
>> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...> wrote:
>> Yes, I just noticed that as well. That's how the tikz pgf code looks (a sequence of line_to and curve_to commands and so on) so it should be easy to port over the various shapes.
>> 
>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
>> On 2015年05月13日 10:12 AM, Neil Girdhar wrote:
>> If you want to make arrowheads look at all decent, they really need to
>> be enclosed in Bezier curves. See the diagram here:
>> 
>> Mpl paths support Bezier curves.
>> http://matplotlib.org/api/path_api.html?highlight=bezier
>> 
>> 
>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>> 
>> The first two look like garbage. The last one is the only one that
>> looks good imho.
>> 
>> That depends on the application, and the observer.
>> 
>> Sure, but I may as well port them all of the tikz arrowheads over since most of the work would be figuring out how to do it.
>> 
>> 
>> 
>> Eric
>> 
>> 
>> Best,
>> 
>> Neil
>> 
>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>> <mailto:ef...@ha...>> wrote:
>> 
>> On 2015年05月13日 9:36 AM, Neil Girdhar wrote:
>> 
>> I don't know matplotlib well enough (yet) to know what the
>> change would
>> consist of.
>> 
>> I suggest you take a look at the beautiful tikz manual:
>> http://pgf.sourceforge.net/pgf_CVS.pdf
>> 
>> 
>> Very helpful, thank you.
>> 
>> 
>> The arrows.meta on page 201–212 are really well-designed and
>> beautiful.
>> 
>> Compare this with matplotlib's custom arrows:
>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>> 
>> How do I make tikz's arrowheads available for all backends?
>> 
>> 
>> My guess offhand is that this is a matter of using the mpl API. I
>> don't think we would want to add all of these types and options to
>> the mpl core; but a toolkit might be ideal for this. The mpl API,
>> which generates the same results for all backends, is quite complete
>> and flexible. Things like arrowheads are Patch objects, and you can
>> specify any path you want. The main trick is figuring out how to
>> handle transforms--what kind of coordinates should the path be
>> specifying? How should things scale as a figure is reshaped and
>> resized?
>> 
>> For many of these types you could also use mpl Line2D objects, for
>> which several properties including cap style can be specified. Not
>> all of the TikZ options would be available, but perhaps enough.
>> 
>> Eric
>> 
>> 
>> 
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud 
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
> 
> 
> 

Do you have the code that you used to draw the arrowhead? I'm up to date
now on the development workflow (
http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm
ready to start working.
Thanks,
Neil
On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
wrote:
> Yes, I fully agree that we need to unify the many different ways to draw
> arrows.
>
> Neil, in case an example would be helpful for you, I have attached a
> module that includes a custom arrowhead class. The arrowhead class works
> with the with the ax.annotate() method. (I like the annotate method
> because it allows me to easily mix and match coordinate systems for arrow
> placement.) As you can see in the attached pdf, the custom arrowhead
> doesn't include fancy Bezier curves, but that could be added.
>
> -Ben
>
>
>
> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>
> The other thing that should be done is to unify the (I think 7?!?) unique
> ways to draw arrows in mpl.
>
> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
> wrote:
>
>> Yes, I just noticed that as well. That's how the tikz pgf code looks (a
>> sequence of line_to and curve_to commands and so on) so it should be easy
>> to port over the various shapes.
>>
>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
>>
>>> On 2015年05月13日 10:12 AM, Neil Girdhar wrote:
>>>
>>>> If you want to make arrowheads look at all decent, they really need to
>>>> be enclosed in Bezier curves. See the diagram here:
>>>>
>>>
>>> Mpl paths support Bezier curves.
>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>
>>>
>>>>
>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>
>>>> The first two look like garbage. The last one is the only one that
>>>> looks good imho.
>>>>
>>>
>>> That depends on the application, and the observer.
>>
>>
>> Sure, but I may as well port them all of the tikz arrowheads over since
>> most of the work would be figuring out how to do it.
>>
>>
>>>
>>>
>>> Eric
>>>
>>>
>>>> Best,
>>>>
>>>> Neil
>>>>
>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>> <mailto:ef...@ha...>> wrote:
>>>>
>>>> On 2015年05月13日 9:36 AM, Neil Girdhar wrote:
>>>>
>>>> I don't know matplotlib well enough (yet) to know what the
>>>> change would
>>>> consist of.
>>>>
>>>> I suggest you take a look at the beautiful tikz manual:
>>>> http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>
>>>>
>>>> Very helpful, thank you.
>>>>
>>>>
>>>> The arrows.meta on page 201–212 are really well-designed and
>>>> beautiful.
>>>>
>>>> Compare this with matplotlib's custom arrows:
>>>>
>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>
>>>> How do I make tikz's arrowheads available for all backends?
>>>>
>>>>
>>>> My guess offhand is that this is a matter of using the mpl API. I
>>>> don't think we would want to add all of these types and options to
>>>> the mpl core; but a toolkit might be ideal for this. The mpl API,
>>>> which generates the same results for all backends, is quite complete
>>>> and flexible. Things like arrowheads are Patch objects, and you can
>>>> specify any path you want. The main trick is figuring out how to
>>>> handle transforms--what kind of coordinates should the path be
>>>> specifying? How should things scale as a figure is reshaped and
>>>> resized?
>>>>
>>>> For many of these types you could also use mpl Line2D objects, for
>>>> which several properties including cap style can be specified. Not
>>>> all of the TikZ options would be available, but perhaps enough.
>>>>
>>>> Eric
>>>>
>>>>
>>>>
>>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
>
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
>
>
>

Wow, this looks great.
Thank you all of you so far for the quick responses and pointers.
I've already done many diagrams in Python-generated TikZ, which I want to
port over to pure Python. They are basically variants of this:
http://www.texample.net/tikz/examples/graph/ . Do you think this will be
possible? That is, drawing nodes with labels inside and then anchoring the
arrows to the edges of the nodes?
With respect to the unification of arrow types, would you be able to point
me to which files or methods in the source they are based on? I would like
to familiarize myself with all of them before I make a proposal of what I
intend to do.
Thanks,
Neil
On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
wrote:
> Yes, I fully agree that we need to unify the many different ways to draw
> arrows.
>
> Neil, in case an example would be helpful for you, I have attached a
> module that includes a custom arrowhead class. The arrowhead class works
> with the with the ax.annotate() method. (I like the annotate method
> because it allows me to easily mix and match coordinate systems for arrow
> placement.) As you can see in the attached pdf, the custom arrowhead
> doesn't include fancy Bezier curves, but that could be added.
>
> -Ben
>
>
>
> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>
> The other thing that should be done is to unify the (I think 7?!?) unique
> ways to draw arrows in mpl.
>
> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
> wrote:
>
>> Yes, I just noticed that as well. That's how the tikz pgf code looks (a
>> sequence of line_to and curve_to commands and so on) so it should be easy
>> to port over the various shapes.
>>
>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
>>
>>> On 2015年05月13日 10:12 AM, Neil Girdhar wrote:
>>>
>>>> If you want to make arrowheads look at all decent, they really need to
>>>> be enclosed in Bezier curves. See the diagram here:
>>>>
>>>
>>> Mpl paths support Bezier curves.
>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>
>>>
>>>>
>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>
>>>> The first two look like garbage. The last one is the only one that
>>>> looks good imho.
>>>>
>>>
>>> That depends on the application, and the observer.
>>
>>
>> Sure, but I may as well port them all of the tikz arrowheads over since
>> most of the work would be figuring out how to do it.
>>
>>
>>>
>>>
>>> Eric
>>>
>>>
>>>> Best,
>>>>
>>>> Neil
>>>>
>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>> <mailto:ef...@ha...>> wrote:
>>>>
>>>> On 2015年05月13日 9:36 AM, Neil Girdhar wrote:
>>>>
>>>> I don't know matplotlib well enough (yet) to know what the
>>>> change would
>>>> consist of.
>>>>
>>>> I suggest you take a look at the beautiful tikz manual:
>>>> http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>
>>>>
>>>> Very helpful, thank you.
>>>>
>>>>
>>>> The arrows.meta on page 201–212 are really well-designed and
>>>> beautiful.
>>>>
>>>> Compare this with matplotlib's custom arrows:
>>>>
>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>
>>>> How do I make tikz's arrowheads available for all backends?
>>>>
>>>>
>>>> My guess offhand is that this is a matter of using the mpl API. I
>>>> don't think we would want to add all of these types and options to
>>>> the mpl core; but a toolkit might be ideal for this. The mpl API,
>>>> which generates the same results for all backends, is quite complete
>>>> and flexible. Things like arrowheads are Patch objects, and you can
>>>> specify any path you want. The main trick is figuring out how to
>>>> handle transforms--what kind of coordinates should the path be
>>>> specifying? How should things scale as a figure is reshaped and
>>>> resized?
>>>>
>>>> For many of these types you could also use mpl Line2D objects, for
>>>> which several properties including cap style can be specified. Not
>>>> all of the TikZ options would be available, but perhaps enough.
>>>>
>>>> Eric
>>>>
>>>>
>>>>
>>>
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Yes, I fully agree that we need to unify the many different ways to draw arrows. 
Neil, in case an example would be helpful for you, I have attached a module that includes a custom arrowhead class. The arrowhead class works with the with the ax.annotate() method. (I like the annotate method because it allows me to easily mix and match coordinate systems for arrow placement.) As you can see in the attached pdf, the custom arrowhead doesn't include fancy Bezier curves, but that could be added.
-Ben
On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
> The other thing that should be done is to unify the (I think 7?!?) unique ways to draw arrows in mpl.
> 
> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...> wrote:
> Yes, I just noticed that as well. That's how the tikz pgf code looks (a sequence of line_to and curve_to commands and so on) so it should be easy to port over the various shapes.
> 
> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
> On 2015年05月13日 10:12 AM, Neil Girdhar wrote:
> If you want to make arrowheads look at all decent, they really need to
> be enclosed in Bezier curves. See the diagram here:
> 
> Mpl paths support Bezier curves.
> http://matplotlib.org/api/path_api.html?highlight=bezier
> 
> 
> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
> 
> The first two look like garbage. The last one is the only one that
> looks good imho.
> 
> That depends on the application, and the observer.
> 
> Sure, but I may as well port them all of the tikz arrowheads over since most of the work would be figuring out how to do it.
> 
> 
> 
> Eric
> 
> 
> Best,
> 
> Neil
> 
> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
> <mailto:ef...@ha...>> wrote:
> 
> On 2015年05月13日 9:36 AM, Neil Girdhar wrote:
> 
> I don't know matplotlib well enough (yet) to know what the
> change would
> consist of.
> 
> I suggest you take a look at the beautiful tikz manual:
> http://pgf.sourceforge.net/pgf_CVS.pdf
> 
> 
> Very helpful, thank you.
> 
> 
> The arrows.meta on page 201–212 are really well-designed and
> beautiful.
> 
> Compare this with matplotlib's custom arrows:
> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
> 
> How do I make tikz's arrowheads available for all backends?
> 
> 
> My guess offhand is that this is a matter of using the mpl API. I
> don't think we would want to add all of these types and options to
> the mpl core; but a toolkit might be ideal for this. The mpl API,
> which generates the same results for all backends, is quite complete
> and flexible. Things like arrowheads are Patch objects, and you can
> specify any path you want. The main trick is figuring out how to
> handle transforms--what kind of coordinates should the path be
> specifying? How should things scale as a figure is reshaped and
> resized?
> 
> For many of these types you could also use mpl Line2D objects, for
> which several properties including cap style can be specified. Not
> all of the TikZ options would be available, but perhaps enough.
> 
> Eric
> 
> 
> 
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Fascinating! Can you "unpack" (heh) that error for us mere mortals? In
particular:
- never seen that "or" syntax before... Is it coercing both expressions as
bool, or is it evaluating to left if bool(left) evaluates to True, else to
right?
- Why do you expect the second expression to work? Is ** supposed to have
lower preference than "or"? (Which seems weird to me.)
Thanks!
Juan.
On Thu, May 14, 2015 at 5:08 AM, Thomas Caswell <tca...@gm...> wrote:
>
> The failures on python nightly are currently due to a bug in python (
> http://bugs.python.org/issue24176)
>
> Tom
>
>
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>