matplotlib-devel Mailing List for matplotlib

> Have you tried:
> ax1.scatter(sanjose_y,sanjose_x,color=(0.9,0.9,0.0),label='SanJose',alpha=0.1)
Yes, the above worked, thank you
--
Andrew 'Boo' Davie

Eero Nevalainen <eer...@in...> writes:
> I'm plotting GPS scatter and I have a problem with the plotting library
> https://sourceforge.net/tracker/?func=detail&aid=2886541&group_id=80706&atid=560720
> Doing a scatterplot with for example scatter(x,y, s=1, c='r') makes black
> dots instead of red ones. 
It's because of the black edgecolor. Try
scatter(x,y,s=1,c='r',edgecolor='None')
to disable drawing the edges.
> Do you devs have an IRC channel? I'd like to talk interactively.
Not that I know of.
-- 
Jouni K. Seppänen
http://www.iki.fi/jks

Hi,
I'm plotting GPS scatter and I have a problem with the plotting library
https://sourceforge.net/tracker/?func=detail&aid=2886541&group_id=80706&atid=560720
I'm comparing different GPS'es and need the colors to separate them. You
can check the current output in
http://users.tkk.fi/~ejnevala/scatterplot.png
Do you devs have an IRC channel? I'd like to talk interactively.
I pledge to donate 5 bucks to matplotlib just for triaging the bug.
-- 
Eero Nevalainen
System Architect
Indagon Ltd.

tcb wrote:
> Hi Mike,
>
> I'm not sure about the textpath functionality. Most of the 'easy'
> marker types have been specified already (triangles, squares etc). Are
> the latex symbols defined somewhere that you could easily extract a
> path description of them, and then pass that to the textpath code you
> have? This would be perfect, since you could then apply the properties
> changes already there (like color, size, linewidth etc), and you
> wouldnt necessarily need latex to render the markers.
>
> Even if you could manage to make a path description for (all) the
> markers, they might not exactly correspond to the latex symbols which
> would be one of the main aims- for eg. using text.usetex with the pdf
> backend you could match the fonts in your graph to your latex document
> and it would all look very nice ;)
>
> I agree that the best approach would be to make a new marker style
> '$...$' and pass the string inside to whatever renders the math text.
>
> I hadn't consider making a patch myself- but perhaps I'll take a look
> and see if something can be done (any pointers on the use of the math
> text code would be appreciated...)- either way I will file an
> enhancement request to keep track of it.
> 
The functionality in textpath.py is able to turn any text (including 
math with the internal render and externally-rendered LaTeX) into a path 
on-the-fly. It should exactly match the rest of the text, as long as 
the usetex option is passed along correctly. Look at 
textpath.text_to_path.get_text_path:
 convert text *s* to path (a tuple of vertices and codes for 
matplotlib.math.Path).
 *prop*
 font property
 *s*
 text to be converted
 
 *usetex*
 If True, use matplotlib usetex mode.
 *ismath*
 If True, use mathtext parser. Effective only if usetex == False.
There's an example of its usage at the bottom of the same file.
It would be great if you wanted to look into this further. Let me know 
if I can provide any more pointers.
Mike
> thanks,
>
> tcb
>
>
>
> On Mon, Oct 26, 2009 at 1:03 PM, Michael Droettboom <md...@st...> wrote:
> 
>> That's a very interesting idea. I actually think that with the recent
>> textpath functionality that Jae-Joon added, we may be able to tie text and
>> markers together without too much pain. Then it can advantage of all the
>> performance optimizations in draw_markers. Each of the marker styles now
>> contains a function that draws a path for the marker and then passes that to
>> draw_marker. We could add one that draws an arbitrary text path, and then
>> passes that along. I propose that Line.set_marker supports a new marker
>> style "$...$" which would render whatever "..." is as math text.
>>
>> Were you offering to try to produce a patch yourself? Either way, it would
>> be great to file an enhancement request in the tracker so this idea doesn't
>> get lost. It's a good one.
>>
>> Mike
>>
>> tcb wrote:
>> 
>>> Hi,
>>>
>>> Is there some way to add support for latex symbols as markers?
>>>
>>> I think it would be an extension of the current methods for plotting
>>> markers- since I dont think all the color, edge, line style etc
>>> properties would be relevant (or even possible). However, it would
>>> allow arbitrary symbols (at least whatever latex can do) to be used,
>>> which would be really useful.
>>>
>>> The current marker set is fine for most simple plots- but when there
>>> are a few different symbols it quickly becomes tricky to find a set
>>> which can easily be distinguished from each other. The other problem
>>> is that when preparing a graph for publication, it is occasionally
>>> necessary to be able to refer to or quote the symbols in the caption
>>> or the main text- and latex symbols in the graphs would make this look
>>> a bit better.
>>>
>>> I've had a quick look at how the marker symbols are implemented, and
>>> it is my impression that it would be reasonably hard to implement a
>>> new symbol of choice. On the other hand, since I am already using
>>> latex to produce all the text in the graph, it seems it should be
>>> fairly straightforward (with some careful attention to the
>>> positioning...) to use the same text-drawing code which is used for
>>> the legend, axes labels etc, to put the markers on the plot.
>>>
>>> Is there any interest in this?
>>>
>>> thanks,
>>>
>>> tcb
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> Come build with us! The BlackBerry(R) Developer Conference in SF, CA
>>> is the only developer event you need to attend this year. Jumpstart your
>>> developing skills, take BlackBerry mobile applications to market and stay
>>> ahead of the curve. Join us from November 9 - 12, 2009. Register now!
>>> http://p.sf.net/sfu/devconference
>>> _______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>> 
>> --
>> Michael Droettboom
>> Science Software Branch
>> Operations and Engineering Division
>> Space Telescope Science Institute
>> Operated by AURA for NASA
>>
>>
>> 
>
> ------------------------------------------------------------------------------
> Come build with us! The BlackBerry(R) Developer Conference in SF, CA
> is the only developer event you need to attend this year. Jumpstart your
> developing skills, take BlackBerry mobile applications to market and stay 
> ahead of the curve. Join us from November 9 - 12, 2009. Register now!
> http://p.sf.net/sfu/devconference
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
> 
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

Hi Mike,
I'm not sure about the textpath functionality. Most of the 'easy'
marker types have been specified already (triangles, squares etc). Are
the latex symbols defined somewhere that you could easily extract a
path description of them, and then pass that to the textpath code you
have? This would be perfect, since you could then apply the properties
changes already there (like color, size, linewidth etc), and you
wouldnt necessarily need latex to render the markers.
Even if you could manage to make a path description for (all) the
markers, they might not exactly correspond to the latex symbols which
would be one of the main aims- for eg. using text.usetex with the pdf
backend you could match the fonts in your graph to your latex document
and it would all look very nice ;)
I agree that the best approach would be to make a new marker style
'$...$' and pass the string inside to whatever renders the math text.
I hadn't consider making a patch myself- but perhaps I'll take a look
and see if something can be done (any pointers on the use of the math
text code would be appreciated...)- either way I will file an
enhancement request to keep track of it.
thanks,
tcb
On Mon, Oct 26, 2009 at 1:03 PM, Michael Droettboom <md...@st...> wrote:
> That's a very interesting idea. I actually think that with the recent
> textpath functionality that Jae-Joon added, we may be able to tie text and
> markers together without too much pain. Then it can advantage of all the
> performance optimizations in draw_markers. Each of the marker styles now
> contains a function that draws a path for the marker and then passes that to
> draw_marker. We could add one that draws an arbitrary text path, and then
> passes that along. I propose that Line.set_marker supports a new marker
> style "$...$" which would render whatever "..." is as math text.
>
> Were you offering to try to produce a patch yourself? Either way, it would
> be great to file an enhancement request in the tracker so this idea doesn't
> get lost. It's a good one.
>
> Mike
>
> tcb wrote:
>>
>> Hi,
>>
>> Is there some way to add support for latex symbols as markers?
>>
>> I think it would be an extension of the current methods for plotting
>> markers- since I dont think all the color, edge, line style etc
>> properties would be relevant (or even possible). However, it would
>> allow arbitrary symbols (at least whatever latex can do) to be used,
>> which would be really useful.
>>
>> The current marker set is fine for most simple plots- but when there
>> are a few different symbols it quickly becomes tricky to find a set
>> which can easily be distinguished from each other. The other problem
>> is that when preparing a graph for publication, it is occasionally
>> necessary to be able to refer to or quote the symbols in the caption
>> or the main text- and latex symbols in the graphs would make this look
>> a bit better.
>>
>> I've had a quick look at how the marker symbols are implemented, and
>> it is my impression that it would be reasonably hard to implement a
>> new symbol of choice. On the other hand, since I am already using
>> latex to produce all the text in the graph, it seems it should be
>> fairly straightforward (with some careful attention to the
>> positioning...) to use the same text-drawing code which is used for
>> the legend, axes labels etc, to put the markers on the plot.
>>
>> Is there any interest in this?
>>
>> thanks,
>>
>> tcb
>>
>>
>> ------------------------------------------------------------------------------
>> Come build with us! The BlackBerry(R) Developer Conference in SF, CA
>> is the only developer event you need to attend this year. Jumpstart your
>> developing skills, take BlackBerry mobile applications to market and stay
>> ahead of the curve. Join us from November 9 - 12, 2009. Register now!
>> http://p.sf.net/sfu/devconference
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>
> --
> Michael Droettboom
> Science Software Branch
> Operations and Engineering Division
> Space Telescope Science Institute
> Operated by AURA for NASA
>
>

On Mon, Oct 26, 2009 at 2:35 AM, <Boo...@cs...> wrote:
> Also (a different problem), I get an error message (when adding a legend, that no labels were defined). This is also changed behaviour since the upgrade. Seems like scatter has changed... but why?
This is a known bug.
http://www.nabble.com/No-legend-using-scatter-function-td24816047.html#a24816047
This is fixed in the svn, and I guess 0.99.1.1 shipped with this fixed.
If you don't want to upgrade, use the workaround in the above post.
Regards,
-JJ

Have you tried:
ax1.scatter(sanjose_y,sanjose_x,color=(0.9,0.9,0.0),label='SanJose',alpha=0.1)
That's what the scatter_demo2.py example does, and it appears to be working.
In general, alpha support is a bit inconsistent, and is the source of a 
number of these kinds of bugs -- where RGBA values are supported in some 
places but not in others. It's on the TODO list to fix, but it's rather 
pervasive so hasn't been tackled yet.
Mike
Boo...@cs... wrote:
> Reporting this as a matplotlib bug because that's where I see the error.
>
> I have some code which was running fine, drawing a scatter plot with transparent/alpha for the colour, like this...
>
> ax1.scatter(sanjose_y,sanjose_x,color=(0.9,0.9,0.0,0.1),label='SanJose')
>
> This used to draw a very faint transparent series of points which (where there were a lot of points) built up a fairly solid colour. Now, after an upgrade to Ubuntu 9.10 I see only solid colour, no transparency/alpha at all. Also (a different problem), I get an error message (when adding a legend, that no labels were defined). This is also changed behaviour since the upgrade. Seems like scatter has changed... but why?
>
> I tried downloading matplotlib source code and compiling -- and despite a few glitches (like, it was by default Mac compilation) -- I think I got that going OK. Still, I see exactly the same behaviour. Scatter is behaving differently, and I really need that alpha/transparency!!!
>
> Neither of these problems were evident on Ubuntu 9.04, and I was using the inbuilt matplotlib for that.
>
> Please excuse if this report is in the wrong place -- my first attempt to report a bug in this package.
>
> Cheers
> A
>
> --
> Andrew 'Boo' Davie
>
> ------------------------------------------------------------------------------
> Come build with us! The BlackBerry(R) Developer Conference in SF, CA
> is the only developer event you need to attend this year. Jumpstart your
> developing skills, take BlackBerry mobile applications to market and stay 
> ahead of the curve. Join us from November 9 - 12, 2009. Register now!
> http://p.sf.net/sfu/devconference
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
> 
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

That's a very interesting idea. I actually think that with the recent 
textpath functionality that Jae-Joon added, we may be able to tie text 
and markers together without too much pain. Then it can advantage of 
all the performance optimizations in draw_markers. Each of the marker 
styles now contains a function that draws a path for the marker and then 
passes that to draw_marker. We could add one that draws an arbitrary 
text path, and then passes that along. I propose that Line.set_marker 
supports a new marker style "$...$" which would render whatever "..." is 
as math text.
Were you offering to try to produce a patch yourself? Either way, it 
would be great to file an enhancement request in the tracker so this 
idea doesn't get lost. It's a good one.
Mike
tcb wrote:
> Hi,
>
> Is there some way to add support for latex symbols as markers?
>
> I think it would be an extension of the current methods for plotting
> markers- since I dont think all the color, edge, line style etc
> properties would be relevant (or even possible). However, it would
> allow arbitrary symbols (at least whatever latex can do) to be used,
> which would be really useful.
>
> The current marker set is fine for most simple plots- but when there
> are a few different symbols it quickly becomes tricky to find a set
> which can easily be distinguished from each other. The other problem
> is that when preparing a graph for publication, it is occasionally
> necessary to be able to refer to or quote the symbols in the caption
> or the main text- and latex symbols in the graphs would make this look
> a bit better.
>
> I've had a quick look at how the marker symbols are implemented, and
> it is my impression that it would be reasonably hard to implement a
> new symbol of choice. On the other hand, since I am already using
> latex to produce all the text in the graph, it seems it should be
> fairly straightforward (with some careful attention to the
> positioning...) to use the same text-drawing code which is used for
> the legend, axes labels etc, to put the markers on the plot.
>
> Is there any interest in this?
>
> thanks,
>
> tcb
>
> ------------------------------------------------------------------------------
> Come build with us! The BlackBerry(R) Developer Conference in SF, CA
> is the only developer event you need to attend this year. Jumpstart your
> developing skills, take BlackBerry mobile applications to market and stay 
> ahead of the curve. Join us from November 9 - 12, 2009. Register now!
> http://p.sf.net/sfu/devconference
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
> 
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

Reporting this as a matplotlib bug because that's where I see the error.
I have some code which was running fine, drawing a scatter plot with transparent/alpha for the colour, like this...
ax1.scatter(sanjose_y,sanjose_x,color=(0.9,0.9,0.0,0.1),label='SanJose')
This used to draw a very faint transparent series of points which (where there were a lot of points) built up a fairly solid colour. Now, after an upgrade to Ubuntu 9.10 I see only solid colour, no transparency/alpha at all. Also (a different problem), I get an error message (when adding a legend, that no labels were defined). This is also changed behaviour since the upgrade. Seems like scatter has changed... but why?
I tried downloading matplotlib source code and compiling -- and despite a few glitches (like, it was by default Mac compilation) -- I think I got that going OK. Still, I see exactly the same behaviour. Scatter is behaving differently, and I really need that alpha/transparency!!!
Neither of these problems were evident on Ubuntu 9.04, and I was using the inbuilt matplotlib for that.
Please excuse if this report is in the wrong place -- my first attempt to report a bug in this package.
Cheers
A
--
Andrew 'Boo' Davie