Re: [Matplotlib-users] why does transform=None cause a patch not to be shown?

Hello,

Not sure this is related, but it's also a behaviour I don't understand
when adding a patch.
Tony Yu has been providing many insightful explanations on artists,
but I'm not there yet...
So my apologies if this has been discussed already on this mailing list.

I'm plotting two subplots and I would like to draw a given rectangle
on both of them.
The rectangle displays if I "add_patch" it to the first subplot only.
It does not display (on either subplot) if I "add_patch" it to both subplots.

I don't understand why this is.  Is this an intentional behaviour?

Below is my script:

-----------------------------------8<-----------------------------------
import matplotlib.pyplot as plt
from scipy import ndimage
from matplotlib import patches

# Next 8 lines don't pertain to the issue--skip.
initmid = plt.imread('movie2_t001_z005_c001.png')
aftermid = plt.imread('movie2_t002_z005_c001.png')
init2 = ndimage.gaussian_filter(initmid, 1)
after2 = ndimage.gaussian_filter(aftermid, 1)
x_in = 580
y_in = 280
dx_in = 40
dy_in = 40

# Draw rectangles to visualize the area of interest:
rect_in = plt.Rectangle((x_in, y_in), dx_in, dy_in,
                        edgecolor='g', facecolor='none')

# Plot 2 different views:
fig, (ax1, ax2) = plt.subplots(nrows=1, ncols=2)
plt.gray()

ax1.imshow(init2)
ax1.add_patch(rect_in)

ax2.imshow(after2)
# ax2.add_patch(rect_in)
plt.show()
-----------------------------------8<-----------------------------------

If I uncomment the second to last line, I don't get any green
rectangle any more.

Thanks,
Marianne