Alpha and colorbar using contourf

When I use contourf with an alpha argument and the “hot” color scheme. The alpha causes the colors to come out lighter but the colorbar does not adjust accordingly. Is this a bug or do I simply need to adjust the colorbar in some manner?

Below is an adaptation of pcolor.py from the screenshots page and attached is the output I see.

I am using matplotlib 0.87.7:

In [3]: matplotlib.version
Out[3]: ‘0.87.7’

example.png

···

from future import division
from pylab import *

def func3(x,y):
return (1- x/2 + x5 + y3)*exp(-x2-y2)

dx, dy = 0.025, 0.025
x = arange(-3.0, 3.0, dx)
y = arange(-3.0, 3.0, dy)
X,Y = meshgrid(x, y)

Z = func3(X, Y)

cset = contourf(Z, arange(-1.2,1.6,0.5),
origin=‘lower’,
extent=(-3,3,-3,3), alpha=.5
)

axis(‘off’)
hot()
colorbar()
title(‘Some like it hot’)
show(‘example’)

Tom,

This is a bug. It looks like I completely forgot about handling alpha when I rewrote the colorbar code. I will try to get it fixed in the next few days. Thanks for the report.

Eric

Tom Denniston wrote:

···

When I use contourf with an alpha argument and the "hot" color scheme. The alpha causes the colors to come out lighter but the colorbar does not adjust accordingly. Is this a bug or do I simply need to adjust the colorbar in some manner?

I am using matplotlib 0.87.7:

In [3]: matplotlib.__version__
Out[3]: '0.87.7'

--------------------------------------------------

from __future__ import division
from pylab import *

def func3(x,y):
    return (1- x/2 + x**5 + y**3)*exp(-x**2-y**2)

dx, dy = 0.025, 0.025
x = arange(-3.0, 3.0, dx)
y = arange(-3.0, 3.0, dy)
X,Y = meshgrid(x, y)

Z = func3(X, Y)

cset = contourf(Z, arange(-1.2,1.6,0.5),
               origin='lower',
               extent=(-3,3,-3,3), alpha=.5
               )

axis('off')
hot()
colorbar()
title('Some like it hot')
show('example')

------------------------------------------------------------------------

------------------------------------------------------------------------

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Thanks Eric.

···

On 11/9/06, Eric Firing <efiring@…202…> wrote:

Tom,

This is a bug. It looks like I completely forgot about handling alpha
when I rewrote the colorbar code. I will try to get it fixed in the

next few days. Thanks for the report.

Eric

Tom Denniston wrote:

When I use contourf with an alpha argument and the “hot” color scheme.
The alpha causes the colors to come out lighter but the colorbar does

not adjust accordingly. Is this a bug or do I simply need to adjust the
colorbar in some manner?

Below is an adaptation of pcolor.py from the screenshots page and
attached is the output I see.

I am using matplotlib 0.87.7:

In [3]: matplotlib.version
Out[3]: ‘0.87.7’


from future import division
from pylab import *

def func3(x,y):
return (1- x/2 + x5 + y3)*exp(-x2-y2)

dx, dy = 0.025, 0.025
x = arange(-3.0, 3.0
, dx)
y = arange(-3.0, 3.0, dy)
X,Y = meshgrid(x, y)

Z = func3(X, Y)

cset = contourf(Z, arange(-1.2,1.6,0.5),
origin=‘lower’,
extent=(-3,3,-3,3), alpha=.5

           )

axis(‘off’)
hot()
colorbar()
title(‘Some like it hot’)
show(‘example’)




Using Tomcat but need to do more? Need to support web services, security?

Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo

http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642



Matplotlib-users mailing list
Matplotlib-users@lists.sourceforge.net

https://lists.sourceforge.net/lists/listinfo/matplotlib-users


Using Tomcat but need to do more? Need to support web services, security?

Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo

http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642


Matplotlib-users mailing list

Matplotlib-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-users