plot range affected by axvspan() call

All,

I have stumbled upon a (for me) unexpected behaviour of axvspan().

import matplotlib.pylab as plt
from numpy import *

x = arange(1000)
y = 0.2*sin(0.02*x)

ax = plt.axes()
plt.axvspan(250, 400, facecolor='g', alpha=0.2)
plt.plot(x,y)
plt.show()

The displayed y range is -0.2 to 1, while from the sine amplitude I would have expected -0.2 to 0.2. The expected y range can be obtained by omitting the axvspan() call and also if it is called *after* plot().

Is this the desired behaviour, especially in view of the dependence on the call order?

__version__ is 1.1.0

Cheers,
Joachim

All,

I have stumbled upon a (for me) unexpected behaviour of axvspan().

import matplotlib.pylab as plt
from numpy import *

x = arange(1000)
y = 0.2*sin(0.02*x)

ax = plt.axes()
plt.axvspan(250, 400, facecolor='g', alpha=0.2)
plt.plot(x,y)
plt.show()

The displayed y range is -0.2 to 1, while from the sine amplitude I
would have expected -0.2 to 0.2. The expected y range can be obtained by
omitting the axvspan() call and also if it is called *after* plot().

Is this the desired behaviour, especially in view of the dependence on
the call order?

No, it is a bug.

Eric

ยทยทยท

On 05/17/2011 01:53 AM, Joachim Saul wrote:

__version__ is 1.1.0

Cheers,
Joachim

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