matplotlib-devel Mailing List for matplotlib

Greetings,
I came across what I would consider an interesting text bug when using
AnchoredText. In summary, when trying to pass a horizontal alignment to the
text, anything but 'left' doesn't work. The text gets positioned around the
left-edge of the text space (left spine of text box + padding). This occurs
both with the "normal" plotting and the ImageGrid.
I went ahead and filed an issue, but didn't know if someone who doesn't'
check the issues list might have a work around. The git issue has a sample
script and image to illustrate the issue.
https://github.com/matplotlib/matplotlib/issues/1742
I'm not sure if this is a continuation of the issues reported in
Issue #1571 <https://github.com/matplotlib/matplotlib/issues/1571>
Pull Request #1081 <https://github.com/matplotlib/matplotlib/issues/1081>
Pull Request #1589 <https://github.com/matplotlib/matplotlib/issues/1589>
I'm in the midst of my dissertation, so I don't have the time right now to
dig into this. If no one else can, I'll take a crack at it in a couple
months when I'm done.
Cheers,
Patrick
---
Patrick Marsh
Ph.D. Candidate / Liaison to the HWT
School of Meteorology / University of Oklahoma
Cooperative Institute for Mesoscale Meteorological Studies
National Severe Storms Laboratory
http://www.patricktmarsh.com

My default interpretation of errors is always relative to the value
because that is how they are reported (100+10-20 not 100+110-80).
(got your 2nd email while writing this)
Would you find this clearer? Maybe xerr and yerr should be split up
xerr/yerr: [ scalar | N, Nx1, or 2xN array-like ]
If a scalar number, len(N) array-like object, or an Nx1 array-like
object, errorbars are drawn x/y +/- value.
If a sequence of shape 2xN, errorbars are drawn at x/y - row1 and x/y + row2
Tom
On Sat, Feb 9, 2013 at 12:49 PM, Markus Haider <mar...@ui...> wrote:
> Hi Tom,
>
> Thank you very much for your answer. Indeed this solves my problem. However,
> I was wondering if the documentation on this is correct.
> At
> http://matplotlib.org/api/axes_api.html?highlight=errorbar#matplotlib.axes.Axes.errorbar
> it says:
>
> xerr/yerr: [ scalar | N, Nx1, or 2xN array-like ]
> If a scalar number, len(N) array-like object, or an Nx1 array-like object,
> errorbars are drawn +/- value.
> If a sequence of shape 2xN, errorbars are drawn at -row1 and +row2
>
> This sounds to me that for a 2xN argument it should be drawn from the actual
> supplied value, or would you interpret this differently?
>
> Thanks,
> Markus
>
> Am 2013年02月08日 22:02, schrieb Thomas Caswell:
>
>> The bar is drawn from `y - yerr_low` to `y + yerr_upp`
>>
>> ax.errorbar(x + .5,y,yerr=[[y - yerr_low],[yerr_upp -
>> y]],fmt='s',markersize=4)
>>
>> will get you what you want.
>>
>> Tom
>>
>> On Fri, Feb 8, 2013 at 8:41 PM, Markus Haider <mar...@ui...>
>> wrote:
>>>
>>> Hi,
>>>
>>> I think I have a problem with errorbars in a log plot. The problem is
>>> reproducible through the enclosed errorbar_log.py file. As you can see I
>>> plot a point with y = 10**(-5) and I want the errorbars drawn from
>>> 10**(-5.5) to 10**(-4.5) which should be symmetric in this plot but
>>> isn't.
>>>
>>> Here is the content of my errorbar_log.py file:
>>>
>>> #!/usr/bin/python
>>> import numpy as np
>>> import matplotlib.pyplot as plt
>>>
>>> fig = plt.figure()
>>> ax = fig.add_subplot(111)
>>> x = 0.0
>>> y = 10**(-5.0)
>>> yerr_low = 10**(-5.5)
>>> yerr_upp = 10**(-4.5)
>>> ax.errorbar(x,y,yerr=[[yerr_low],[yerr_upp]],fmt='o',markersize=4)
>>> ax.set_xlim(-1.0,1.0)
>>> ax.set_ylim(1E-6,1E-3)
>>> ax.set_yscale('log')
>>> plt.savefig('errorbar.png')
>>>
>>> ---------------------------------------------
>>>
>>> 10**(-5.5) = 3.162277660168379e-06
>>> and 10**(-4.5) = 3.1622776601683795e-05
>>>
>>> but you can see that the lower boundary is not at the calculated value.
>>> <http://matplotlib.1069221.n5.nabble.com/file/n40412/errorbar.png>
>>>
>>>
>>> Do I misunderstand the behaviour of the errorbar function or is this a
>>> bug?
>>>
>>> Cheers,
>>> Markus
>>>
>>>
>>>
>>> --
>>> View this message in context:
>>> http://matplotlib.1069221.n5.nabble.com/Errorbar-problem-tp40412.html
>>> Sent from the matplotlib - devel mailing list archive at Nabble.com.
>>>
>>>
>>> ------------------------------------------------------------------------------
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>>> Matplotlib-devel mailing list
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>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>
>>
>> --
>> Thomas Caswell
>> tca...@gm...
>>
>
--
Thomas Caswell
tca...@gm...

Actually never mind, I think I just interpreted it wrong. However it 
could perhaps be more clear if it would say something like
If a sequence of shape 2xN, errorbars are drawn at y +/- row1/row2
Thanks,
Markus
Am 2013年02月09日 13:49, schrieb Markus Haider:
> Hi Tom,
>
> Thank you very much for your answer. Indeed this solves my problem.
> However, I was wondering if the documentation on this is correct.
> At
> http://matplotlib.org/api/axes_api.html?highlight=errorbar#matplotlib.axes.Axes.errorbar
> it says:
>
> xerr/yerr: [ scalar | N, Nx1, or 2xN array-like ]
> If a scalar number, len(N) array-like object, or an Nx1 array-like
> object, errorbars are drawn +/- value.
> If a sequence of shape 2xN, errorbars are drawn at -row1 and +row2
>
> This sounds to me that for a 2xN argument it should be drawn from the
> actual supplied value, or would you interpret this differently?
>
> Thanks,
> Markus
>
> Am 2013年02月08日 22:02, schrieb Thomas Caswell:
>> The bar is drawn from `y - yerr_low` to `y + yerr_upp`
>>
>> ax.errorbar(x + .5,y,yerr=[[y - yerr_low],[yerr_upp -
>> y]],fmt='s',markersize=4)
>>
>> will get you what you want.
>>
>> Tom
>>
>> On Fri, Feb 8, 2013 at 8:41 PM, Markus Haider <mar...@ui...> wrote:
>>> Hi,
>>>
>>> I think I have a problem with errorbars in a log plot. The problem is
>>> reproducible through the enclosed errorbar_log.py file. As you can see I
>>> plot a point with y = 10**(-5) and I want the errorbars drawn from
>>> 10**(-5.5) to 10**(-4.5) which should be symmetric in this plot but isn't.
>>>
>>> Here is the content of my errorbar_log.py file:
>>>
>>> #!/usr/bin/python
>>> import numpy as np
>>> import matplotlib.pyplot as plt
>>>
>>> fig = plt.figure()
>>> ax = fig.add_subplot(111)
>>> x = 0.0
>>> y = 10**(-5.0)
>>> yerr_low = 10**(-5.5)
>>> yerr_upp = 10**(-4.5)
>>> ax.errorbar(x,y,yerr=[[yerr_low],[yerr_upp]],fmt='o',markersize=4)
>>> ax.set_xlim(-1.0,1.0)
>>> ax.set_ylim(1E-6,1E-3)
>>> ax.set_yscale('log')
>>> plt.savefig('errorbar.png')
>>>
>>> ---------------------------------------------
>>>
>>> 10**(-5.5) = 3.162277660168379e-06
>>> and 10**(-4.5) = 3.1622776601683795e-05
>>>
>>> but you can see that the lower boundary is not at the calculated value.
>>> <http://matplotlib.1069221.n5.nabble.com/file/n40412/errorbar.png>
>>>
>>>
>>> Do I misunderstand the behaviour of the errorbar function or is this a bug?
>>>
>>> Cheers,
>>> Markus
>>>
>>>
>>>
>>> --
>>> View this message in context: http://matplotlib.1069221.n5.nabble.com/Errorbar-problem-tp40412.html
>>> Sent from the matplotlib - devel mailing list archive at Nabble.com.
>>>
>>> ------------------------------------------------------------------------------
>>> Free Next-Gen Firewall Hardware Offer
>>> Buy your Sophos next-gen firewall before the end March 2013
>>> and get the hardware for free! Learn more.
>>> http://p.sf.net/sfu/sophos-d2d-feb
>>> _______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>> --
>> Thomas Caswell
>> tca...@gm...
>>
>
> ------------------------------------------------------------------------------
> Free Next-Gen Firewall Hardware Offer
> Buy your Sophos next-gen firewall before the end March 2013
> and get the hardware for free! Learn more.
> http://p.sf.net/sfu/sophos-d2d-feb
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>

Hi Tom,
Thank you very much for your answer. Indeed this solves my problem. 
However, I was wondering if the documentation on this is correct.
At 
http://matplotlib.org/api/axes_api.html?highlight=errorbar#matplotlib.axes.Axes.errorbar 
it says:
xerr/yerr: [ scalar | N, Nx1, or 2xN array-like ]
If a scalar number, len(N) array-like object, or an Nx1 array-like 
object, errorbars are drawn +/- value.
If a sequence of shape 2xN, errorbars are drawn at -row1 and +row2
This sounds to me that for a 2xN argument it should be drawn from the 
actual supplied value, or would you interpret this differently?
Thanks,
Markus
Am 2013年02月08日 22:02, schrieb Thomas Caswell:
> The bar is drawn from `y - yerr_low` to `y + yerr_upp`
>
> ax.errorbar(x + .5,y,yerr=[[y - yerr_low],[yerr_upp -
> y]],fmt='s',markersize=4)
>
> will get you what you want.
>
> Tom
>
> On Fri, Feb 8, 2013 at 8:41 PM, Markus Haider <mar...@ui...> wrote:
>> Hi,
>>
>> I think I have a problem with errorbars in a log plot. The problem is
>> reproducible through the enclosed errorbar_log.py file. As you can see I
>> plot a point with y = 10**(-5) and I want the errorbars drawn from
>> 10**(-5.5) to 10**(-4.5) which should be symmetric in this plot but isn't.
>>
>> Here is the content of my errorbar_log.py file:
>>
>> #!/usr/bin/python
>> import numpy as np
>> import matplotlib.pyplot as plt
>>
>> fig = plt.figure()
>> ax = fig.add_subplot(111)
>> x = 0.0
>> y = 10**(-5.0)
>> yerr_low = 10**(-5.5)
>> yerr_upp = 10**(-4.5)
>> ax.errorbar(x,y,yerr=[[yerr_low],[yerr_upp]],fmt='o',markersize=4)
>> ax.set_xlim(-1.0,1.0)
>> ax.set_ylim(1E-6,1E-3)
>> ax.set_yscale('log')
>> plt.savefig('errorbar.png')
>>
>> ---------------------------------------------
>>
>> 10**(-5.5) = 3.162277660168379e-06
>> and 10**(-4.5) = 3.1622776601683795e-05
>>
>> but you can see that the lower boundary is not at the calculated value.
>> <http://matplotlib.1069221.n5.nabble.com/file/n40412/errorbar.png>
>>
>>
>> Do I misunderstand the behaviour of the errorbar function or is this a bug?
>>
>> Cheers,
>> Markus
>>
>>
>>
>> --
>> View this message in context: http://matplotlib.1069221.n5.nabble.com/Errorbar-problem-tp40412.html
>> Sent from the matplotlib - devel mailing list archive at Nabble.com.
>>
>> ------------------------------------------------------------------------------
>> Free Next-Gen Firewall Hardware Offer
>> Buy your Sophos next-gen firewall before the end March 2013
>> and get the hardware for free! Learn more.
>> http://p.sf.net/sfu/sophos-d2d-feb
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
>
> --
> Thomas Caswell
> tca...@gm...
>

On Feb 8, 2013 11:14 PM, "Benjamin Root" <ben...@ou...> wrote:
>
> Just a crazy thought, but why are we trying to treat "title" and such as
properties? When I think of properties for matplotlib, I think of
edgecolors, fontsize, and linestyles. Why don't we solve that problem
first?
In my mind there are several reasons.
First, I personally see things like "title" as properties as well. I can
see why not everyone would, but that would seem to me a reason to keep the
setter functions at least in some cases rather than a reason to not
implement properties.
Second, it is more consistent. Users wouldn't need to remember on a
case-by-basis whether to use a setter or a property.
Third, it would require making sure the API is clan and consistent behind
the scenes. The more complex setters like title would just be wrappers
around the properties or property functions, so there would need to be ways
to access the individual arguments on their own.
That being said, it would be possible to implement properties in stages,
with simpler ones done first and more complex ones done later.
However, there are three reasons I did not include this in my proposed
plan. First, it would mean we lose consistency, perhaps for a few releases.
Second, it could lead to the API breakage being split over several releases
rather than happening all at once. Third, if we do the behind-the-scenes
cleanups first then this isn't an issue to begin with since complexities
will already be dealt with.

The bar is drawn from `y - yerr_low` to `y + yerr_upp`
ax.errorbar(x + .5,y,yerr=[[y - yerr_low],[yerr_upp -
y]],fmt='s',markersize=4)
will get you what you want.
Tom
On Fri, Feb 8, 2013 at 8:41 PM, Markus Haider <mar...@ui...> wrote:
> Hi,
>
> I think I have a problem with errorbars in a log plot. The problem is
> reproducible through the enclosed errorbar_log.py file. As you can see I
> plot a point with y = 10**(-5) and I want the errorbars drawn from
> 10**(-5.5) to 10**(-4.5) which should be symmetric in this plot but isn't.
>
> Here is the content of my errorbar_log.py file:
>
> #!/usr/bin/python
> import numpy as np
> import matplotlib.pyplot as plt
>
> fig = plt.figure()
> ax = fig.add_subplot(111)
> x = 0.0
> y = 10**(-5.0)
> yerr_low = 10**(-5.5)
> yerr_upp = 10**(-4.5)
> ax.errorbar(x,y,yerr=[[yerr_low],[yerr_upp]],fmt='o',markersize=4)
> ax.set_xlim(-1.0,1.0)
> ax.set_ylim(1E-6,1E-3)
> ax.set_yscale('log')
> plt.savefig('errorbar.png')
>
> ---------------------------------------------
>
> 10**(-5.5) = 3.162277660168379e-06
> and 10**(-4.5) = 3.1622776601683795e-05
>
> but you can see that the lower boundary is not at the calculated value.
> <http://matplotlib.1069221.n5.nabble.com/file/n40412/errorbar.png>
>
>
> Do I misunderstand the behaviour of the errorbar function or is this a bug?
>
> Cheers,
> Markus
>
>
>
> --
> View this message in context: http://matplotlib.1069221.n5.nabble.com/Errorbar-problem-tp40412.html
> Sent from the matplotlib - devel mailing list archive at Nabble.com.
>
> ------------------------------------------------------------------------------
> Free Next-Gen Firewall Hardware Offer
> Buy your Sophos next-gen firewall before the end March 2013
> and get the hardware for free! Learn more.
> http://p.sf.net/sfu/sophos-d2d-feb
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
--
Thomas Caswell
tca...@gm...

Hi, 
I think I have a problem with errorbars in a log plot. The problem is
reproducible through the enclosed errorbar_log.py file. As you can see I
plot a point with y = 10**(-5) and I want the errorbars drawn from
10**(-5.5) to 10**(-4.5) which should be symmetric in this plot but isn't. 
Here is the content of my errorbar_log.py file: 
#!/usr/bin/python 
import numpy as np 
import matplotlib.pyplot as plt 
fig = plt.figure() 
ax = fig.add_subplot(111) 
x = 0.0 
y = 10**(-5.0) 
yerr_low = 10**(-5.5) 
yerr_upp = 10**(-4.5) 
ax.errorbar(x,y,yerr=[[yerr_low],[yerr_upp]],fmt='o',markersize=4) 
ax.set_xlim(-1.0,1.0) 
ax.set_ylim(1E-6,1E-3) 
ax.set_yscale('log') 
plt.savefig('errorbar.png') 
--------------------------------------------- 
10**(-5.5) = 3.162277660168379e-06 
and 10**(-4.5) = 3.1622776601683795e-05 
but you can see that the lower boundary is not at the calculated value. 
<http://matplotlib.1069221.n5.nabble.com/file/n40412/errorbar.png> 
Do I misunderstand the behaviour of the errorbar function or is this a bug? 
Cheers, 
Markus 
--
View this message in context: http://matplotlib.1069221.n5.nabble.com/Errorbar-problem-tp40412.html
Sent from the matplotlib - devel mailing list archive at Nabble.com.