I have some stupid questions about how to use colorbar.
1) I would like to be able to put the colorbar where I went: top, bottom,
left, right. For what I see I can do only a vertical left and horizontal
bottom ones (with a simple use of the function).
I know that it's possible to do a colorbar only but it's difficult to place
them a little bit automatically and that bring my second question.
2) I would like that the colorbar with exactly the same size than the image I
plot with pcolor. It's working when I'm not using the aspect='equal' in the
subplot but not with this option. Naturally I want to not change the aspect
of my image and so it's a big problem for me. The only solution I found is to
manipulate the colorbar with the shrink valu but it's a little bit painfull
especially the value change for each pcolor image (they doesn't have always
the same size).
3) I would like to give a label to the colorbar (ie if the colorbar is at the
bottom a label under the colorbar etc). To tell people what means the colors
but I didn't find anyway to do it. xlabel work for the pcolor object (as
expected) and there are no colorbar.xlabel function.
Thank you for any help.
N.
ps: i join a simple script to show my problem
#!/usr/bin/env python
import pylab
import numpy
a = numpy.arange(100).reshape((10,10))
fig1 = pylab.figure()
ax = fig1.add_subplot(141)
im = ax.pcolor(a)
fig1.colorbar(im,orientation='horizontal')
pylab.xlabel('label')
ax = fig1.add_subplot(142)
im = ax.pcolor(a)
fig1.colorbar(im,orientation='vertical')
pylab.xlabel('label')
ax = fig1.add_subplot(143,aspect='equal')
im = ax.pcolor(a)
fig1.colorbar(im,orientation='vertical')
pylab.xlabel('label')
ax = fig1.add_subplot(144,aspect='equal')
im = ax.pcolor(a)
fig1.colorbar(im,orientation='horizontal')
pylab.xlabel('label')
I have some stupid questions about how to use colorbar.
1) I would like to be able to put the colorbar where I went: top, bottom, left, right. For what I see I can do only a vertical left and horizontal bottom ones (with a simple use of the function).
I know that it's possible to do a colorbar only but it's difficult to place them a little bit automatically and that bring my second question.
This looks like a feature request: instead of specifying "horizontal" or "vertical", be able to specify "top", "bottom", "left", or "right". This is fairly easy in principle, but there are some wrinkles such that I am not sure it would be satisfactory in practice--some custom adjustments might usually be needed depending on whether the main axes have a title (in the case of "top") or an xlabel (in the case of "left"). You may be better off simply figuring out what main and colorbar axes positions work best for your particular case and then making those axes explicitly.
2) I would like that the colorbar with exactly the same size than the image I plot with pcolor. It's working when I'm not using the aspect='equal' in the subplot but not with this option. Naturally I want to not change the aspect of my image and so it's a big problem for me. The only solution I found is to manipulate the colorbar with the shrink valu but it's a little bit painfull especially the value change for each pcolor image (they doesn't have always the same size).
This is a common request, and a reasonable one, but unfortunately it is not straightforward to implement automatically given mpl's internal structure. Again, however, you get the desired result quite easily by creating your own axes explicitly.
3) I would like to give a label to the colorbar (ie if the colorbar is at the bottom a label under the colorbar etc). To tell people what means the colors but I didn't find anyway to do it. xlabel work for the pcolor object (as expected) and there are no colorbar.xlabel function.
Use the set_label() method.
...
cbar = fig1.colorbar(im,orientation='horizontal')
cbar.set_label('label')
...
Le Sunday 09 March 2008 14:32:05 Eric Firing, vous avez écrit :
> Hello,
>
> I have some stupid questions about how to use colorbar.
>
> 1) I would like to be able to put the colorbar where I went: top, bottom,
> left, right. For what I see I can do only a vertical left and horizontal
> bottom ones (with a simple use of the function).
> I know that it's possible to do a colorbar only but it's difficult to
> place them a little bit automatically and that bring my second question.
This looks like a feature request: instead of specifying "horizontal" or
"vertical", be able to specify "top", "bottom", "left", or "right".
This is fairly easy in principle, but there are some wrinkles such that
I am not sure it would be satisfactory in practice--some custom
adjustments might usually be needed depending on whether the main axes
have a title (in the case of "top") or an xlabel (in the case of
"left"). You may be better off simply figuring out what main and
colorbar axes positions work best for your particular case and then
making those axes explicitly.
I agree it's more feature request. I'll look on how to implement your
suggestion.
> 2) I would like that the colorbar with exactly the same size than the
> image I plot with pcolor. It's working when I'm not using the
> aspect='equal' in the subplot but not with this option. Naturally I want
> to not change the aspect of my image and so it's a big problem for me.
> The only solution I found is to manipulate the colorbar with the shrink
> valu but it's a little bit painfull especially the value change for each
> pcolor image (they doesn't have always the same size).
This is a common request, and a reasonable one, but unfortunately it is
not straightforward to implement automatically given mpl's internal
structure. Again, however, you get the desired result quite easily by
creating your own axes explicitly.
This is what I was afraid... So I have a stupid question but how to do this,
create the axes at the same place than the pcolor image?
I can see how I can recuperate the axes coordinates but I don't know how to
use them:
im = pylab.pcolor(a)
ax = im.get_axes()
cs = pylab.colorbar()
but after I'm a little bit lost...
> 3) I would like to give a label to the colorbar (ie if the colorbar is at
> the bottom a label under the colorbar etc). To tell people what means the
> colors but I didn't find anyway to do it. xlabel work for the pcolor
> object (as expected) and there are no colorbar.xlabel function.
Use the set_label() method.
...
cbar = fig1.colorbar(im,orientation='horizontal')
cbar.set_label('label')
...