Re: [Matplotlib-users] placing a plot on top of an imshow

Can you just reuse the ax1 for plotting? I guess that might be the easiest way.

With imshow, the location of ax1 is determined at the drawing time,
therefore you need a way to adjust the location of ax2 after this
happens. Doing this manually requires some internal knowledge of mpl.

If you use 0.99 and later, you can use axes_grid toolkits. Here is an
example code.

import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid.inset_locator import inset_axes

fig = plt.figure(1, [5.5, 3])
ax = fig.add_subplot(1,1,1)
ax.set_aspect(1.)

axins1 = inset_axes(ax, width="100%", height="20%",
                   loc=3, borderpad=0,
                   axes_kwargs=dict(frameon=False)
                   )

axins1.xaxis.set_visible(False)
axins1.yaxis.set_visible(False)
axins1.plot([0, 0.5, 1], [0,1,0])

plt.show()

See here for more details.

http://matplotlib.sourceforge.net/mpl_toolkits/axes_grid/users/overview.html

One thing to note, the current design of mpl does not allow you to
share axis when aspect is set(i.e., w/ imshow) (or you have to have
adjustable="datalim"), although there is a way to do it with
axes_grid.

Regards,

-JJ



On Wed, Sep 30, 2009 at 1:50 AM, rafa5 <rap...@ya...> wrote:
>
> Hi guys,
>
> I'm having problems creating a plot. I attached a crude version that I drew
> with Gimp to show what I actually want to do with matplotlib
> http://www.nabble.com/file/p25667058/example2.png example2.png . Basically
> it boils down to placing an axes instance on top of an existing axes with an
> imshow already on it. In the end I would like to have a kind of lineout of
> the values of the array of the imshow along an x=constant & y=constant line.
> So my pathetic (and unsuccesful attempt) is something like:
>
> import matplotlib.pyplot as p
> fig = p.figure(1)
>
> ax1_box = [0.1, 0.1, 0.5, 0.5]
> ax2_box = [0.1, 0.1, 0.5, 0.1]
>
> ax1 = fig.add_axes( ax1_box )
> ax1.imshow(data)
>
> ax2 = fig.add_axes( ax2_box, frameon=False)
> ax2.plot( data[5 , :] )                              #lineout of 6th row for
> example
> p.setp(ax2b, xticks=[], yticks=[])
>
>
> My problems:
> as I don't want to add axis labels ax2 data plot is wider than ax1 data
> plot.
> when i resize the window ax1 and ax2 move relative to another.
> I hope it's possible to also do the lineput along the vertical (y) axis.
> I'm too stupid to figure this out myself.
>
> Thanks a lot in advance for any suggestions :)
>
> Raphael
> --
> View this message in context: http://www.nabble.com/placing-a-plot-on-top-of-an-imshow-tp25667058p25667058.html
> Sent from the matplotlib - users mailing list archive at Nabble.com.
>
>
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