[Numpy-discussion] 2D (or n-d) fancy indexing?
Wed Oct 8 20:44:15 CDT 2008
> You need to give an array for each axis. Each of these arrays will be
> broadcast against each other to form three arrays of the desired shape
> of composite. This is discussed in the manual here:
> Conceptually, you need arrays A, B, and C such that
> composite[x,y] == images[A[x,y], B[x,y], C[x,y]]
> for all x,y
Aha -- thanks especially for the clear illustration of what B and C
need to be. That really helps.
> In : composite = images[map, arange(Nx)[:,newaxis], arange(Ny)]
> When arange(Nx)[:,newaxis] and arange(Ny) get broadcasted with map,
> you get (480,640) arrays like you would get with mgrid[0:Nx,0:Ny].
That's very handy indeed. Thanks for your help!
More information about the Numpy-discussion