Matplotlib子图内容使用set_xlim，set_ylim消失

Question

I am trying to construct a plot where I have a fixed number of rows but differing number of columns for each row. The code I use for plotting is equivalent to:

import matplotlib.pyplot as pl
pl.figure()
pl.ion()
pl.subplot(2,1,1)
pl.title("Sets the title for top plot")

plotData(data[0]) # Function that plots data in this first row

for i in range(3):
    pl.subplot(2,3,4+i)
    pl.title("Sets the title of each subplot in second row")
    plotData(data[i+1]) # Plots the data in second row

Now for some reason the data plotted in the subplots of the second row disappears. When I debug it it seems as it is there until returning from the plotData() function within the for-loop (or possibly upon calling the next subplot command - but this does not explaing why the last subplot is empty ...).

EDIT:

There was code at the end of the plotData() function that triggered the problem:

pl.gca().set_xlim(0,15)
pl.gca().set_ylim(0,15)

Does this mean that I can not set the x,y-limits after plotting the data, or what am I doing wrong here?

A pastebin of the minimal example showing the problem can be found here

Answer 1

OK, that was embarrassing. If you take a look at the code on pastebin the problem was that the xlim and ylim that I was setting did not take into account the fact that I switched direction of the coordinate system (in y-direction). In plotData() :

for i,dset in enumerate(data):
    x = np.array([point['x'] for point in dset])
    y = np.array([-point['y'] for point in dset])

My calls to set_xlim and set_ylim did exactly what they were supposed to, it was just that with the limits I set the data was no longer visible in these plots (since I switched the sign of the y-axis on the data but not on the limits).

Answer 2

I agree with @Zhenya - I don't see this functionality with the latest matplotlib (the development version 1.3-dev and suspect it is fixed in at least v1.2.0, but maybe even as early as v1.0.1).

HTH,

UPDATE: Added output from mpl v1.2.0 :

> python
Python 2.7.2
Type "help", "copyright", "credits" or "license" for more information.
>>> import matplotlib
>>> print matplotlib.__version__
1.2.0
>>> 
>>> import matplotlib.pyplot as plt
>>> 
>>> plt.ion()
>>> 
>>> plt.subplot(2,1,1)
<matplotlib.axes.AxesSubplot object at 0x283d790>
>>> plt.title("Sets the title for top pltot")
<matplotlib.text.Text object at 0x2851f50>
>>> 
>>> plt.plot(range(10, 0, -1))
[<matplotlib.lines.Line2D object at 0x2c40790>]
>>> 
>>> for i in range(3):
...     plt.subplot(2,3,4+i)
...     plt.title("Sets the title of each subplot in second row")
...     plt.plot(range(10))
... 
<matplotlib.axes.AxesSubplot object at 0x2c40e90>
<matplotlib.text.Text object at 0x2c64a90>
[<matplotlib.lines.Line2D object at 0x2c6e990>]
<matplotlib.axes.AxesSubplot object at 0x2c6ec10>
<matplotlib.text.Text object at 0x2e6c810>
[<matplotlib.lines.Line2D object at 0x2e78110>]
<matplotlib.axes.AxesSubplot object at 0x2e78390>
<matplotlib.text.Text object at 0x2e8ced0>
[<matplotlib.lines.Line2D object at 0x2e98610>]