matplotlib-users Mailing List for matplotlib

Hi All,

I am plotting on two different y-axes: one on the left (ax1) and one on 
the right (ax2). Both share the same x-axes. The problem I am facing 
relates back to the zorder of the legend (at least, that is what I 
think): I want it to be on the foreground at all times. In order to do 
so, I change the zorder of the ax1.legend (left y axes) such that the 
ax2.plots (right y-axes) are under ax1.legend. However, that doesn't 
work: all the plots on the right axes (so using ax2) end up above the 
legend 1 on the left, despite having a lower zorder.

Note that I am also giving the grids on both ax1 and ax2 a lower zorder 
value compared to the legends, but the grid still ends up on top of 
legend 1 on the left.

# version info:
# Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41) [GCC 4.4.3] on linux2
# NumPy 1.6.1, Matplotlib 1.1.0
import pylab as plt
import numpy as np

# plotting on the left y-axes,
ax1 = plt.axes(zorder=10)
ax1.plot(range(0,5,1), 'r', label='ax1 ax1 ax1 ax1', zorder=11)
ax1.plot(np.arange(3,4.1,1), 'r--', label='ax1 ax1 ax1 ax1', zorder=12)
gr1 = ax1.grid(zorder=13)

# legend of the left y-axes, force high zorder
leg1 = ax1.legend(loc='upper left')
leg1.set_zorder(30)

# plotting on the right y-axes,
ax2 = plt.twinx()
ax2.set_zorder(20)
ax2.plot(range(4,-1,-1), 'b', label='ax2 ax2 ax2 ax2', zorder=21)
ax2.plot(np.arange(4,2.9,-1), np.arange(3,4.1,1), 'b--',
label='ax2 ax2 ax2 ax2', zorder=22)
gr2 = ax2.grid(zorder=23)

# legend of the right y-axes, force high zorder
leg2 = ax2.legend(loc='upper right')
leg2.set_zorder(40)

print '======= zorder:'
print ' ax1: %i' % ax1.get_zorder()
print ' ax2: %i' % ax2.get_zorder()
print 'leg1: %i' % leg1.get_zorder()
print 'leg2: %i' % leg2.get_zorder()

What am I missing here?

Thanks,
David

On Thursday, March 22, 2012, Alexis Praga <ale...@fr...> wrote:
> Hi,
>
> After using Matplotlib for some time, I would like to give something
> back to the community :)
> How can I contribute ? I am aware that reporting and documentating the
> project is always appreciated, but are there specific needs ? For
> exemple, does a "TODO" list exist ?
>

Alexis,

Most work that goes on is "scratching our itches", so we don't have TODO
lists per se.  However, over on the github issue tracker, you can search
for any issues that have been tagged as "need_confirmation", "wishlist", or
just see what issues have yet to be assigned to anybody.  Another way to
contribute is to review pull requests, testing them out and reporting
whether or not they work as advertised and/or they break something
unexpectedly.

We are always glad to have more eyes on matplotlib!

Cheers!
Ben Root

Hi All,

I am plotting on two different y-axes: one on the left (ax1) and one on 
the right (ax2). Both share the same x-axes. The problem I am facing 
relates back to the zorder of the legend (at least, that is what I 
think): I want it to be on the foreground at all times. In order to do 
so, I change the zorder of the ax1.legend (left y axes) such that the 
ax2.plots (right y-axes) are under ax1.legend. However, that doesn't 
work: all the plots on the right axes (so using ax2) end up above the 
legend 1 on the left, despite having a lower zorder.

Note that I am also giving the grids on both ax1 and ax2 a lower zorder 
value compared to the legends, but the grid still ends up on top of 
legend 1 on the left.

# version info:

# Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41) [GCC 4.4.3] on linux2

# NumPy 1.6.1, Matplotlib 1.1.0

import pylab as plt

import numpy as np

# plotting on the left y-axes,

ax1 = plt.axes(zorder=10)

ax1.plot(range(0,5,1), 'r', label='ax1 ax1 ax1 ax1', zorder=11)

ax1.plot(np.arange(3,4.1,1), 'r--', label='ax1 ax1 ax1 ax1', zorder=12)

gr1 = ax1.grid(zorder=13)

# legend of the left y-axes, force high zorder

leg1 = ax1.legend(loc='upper left')

leg1.set_zorder(30)

# plotting on the right y-axes,

ax2 = plt.twinx()

ax2.set_zorder(20)

ax2.plot(range(4,-1,-1), 'b', label='ax2 ax2 ax2 ax2', zorder=21)

ax2.plot(np.arange(4,2.9,-1), np.arange(3,4.1,1), 'b--',

label='ax2 ax2 ax2 ax2', zorder=22)

gr2 = ax2.grid(zorder=23)

# legend of the right y-axes, force high zorder

leg2 = ax2.legend(loc='upper right')

leg2.set_zorder(40)

print '======= zorder:'

print ' ax1: %i' % ax1.get_zorder()

print ' ax2: %i' % ax2.get_zorder()

print 'leg1: %i' % leg1.get_zorder()

print 'leg2: %i' % leg2.get_zorder()


What am I missing here?
Thanks,
David

Hi,

After using Matplotlib for some time, I would like to give something
back to the community :)
How can I contribute ? I am aware that reporting and documentating the
project is always appreciated, but are there specific needs ? For
exemple, does a "TODO" list exist ?


Thanks

PS : Last time I asked for help, I forgot to thanks the people who
replied. So, Jeff and the others, you have my thanks :)

For the following code, if I remove the transform=None a green patch is
shown.  If it is in, it is not shown.  I would think that transform=None
should have no effect.  Why is this?

Thanks,
Che


import matplotlib.pyplot as plt
import matplotlib.patches as patches
from matplotlib.path import Path

fig = plt.figure()
ax = fig.add_subplot(111)

start = 0.2
stop = .6

verts = [
    (start, .2), # left, bottom
    (start, .4), # left, top
    (stop, .4), # right, top
    (stop, .2), # right, bottom
    (0., 0.), # ignored
    ]
codes = [Path.MOVETO,
         Path.LINETO,
         Path.LINETO,
         Path.LINETO,
         Path.CLOSEPOLY,
         ]

path = Path(verts, codes)

patch = patches.PathPatch(path, facecolor='g',
                          lw=1, edgecolor='grey',transform=None )

ax.add_patch(patch)

plt.show()