Re: [Matplotlib-users] Plotting Scalar on a Circular Grid

[Lorenzo I. <lor...@gm...>]

Hello,
I'll try to make myself clear with a simple example: consider a circle
in 2D Cartesian coordinates (x,y) (my domain).
On that circle, for each (x,y) coordinate, you want to plot the function

f(x,y)=x+y

How would you do that in pylab? perhaps I should have called this a
surface plot (as if I was plotting a temperature field on a tube
cross-section)
This is easy to do in pylab if the domain is e.g. a square,  but I do
not know how to handle the simple case I described above conveniently.
Many thanks

Lorenzo

2009/4/2 Jae-Joon Lee <lee...@gm...>:
> On Wed, Apr 1, 2009 at 6:50 AM, Lorenzo Isella <lor...@gm...> wrote:
>> Now, I would like to plot exactly the same function but on a circular
>> domain (circle of radius 1 centered at (0,0)).
>
> You have an image with x,y spanning from -1 to 1. How do you transform
> your x,y coordinate to r, theta? Or, x,y in your example  actually
> corresponds to r, theta in polar coordinate?
> In that case, is it simply that you want to your image centered at
> (0,0)? Use the extent keyword of imshow command.
>
>  http://matplotlib.sourceforge.net/api/pyplot_api.html#matplotlib.pyplot.imshow
>
> It is not clear what you want.
> Regards,
>
> -JJ
>



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