Ravel multi index

[MrBago]

This should make travis a little more happy. btw, do you guys know what version of numpy travis is using to test dipy?

Bago

[travisbot]

This pull request fails (merged 001a6d49 into 73e8e16).

[travisbot]

This pull request fails (merged b634807 into 73e8e16).

[arokem]

I am guessing this is what we get: http://packages.debian.org/stable/python-numpy

since the .travis.yml file goes and apt-get's numpy for the environment it builds and runs the tests on

[arokem]

Maybe you could copy over the docstring examples from numpy here, so they get tested.

[stefanv]

Sorry, I'm a bit late to the party--can you explain to me why we need unravel_multi_index in the first place?

[MrBago]

We want to use fiber tracking to create a connectivity matrix. The fiber
tracking streamlines each have a start and an end. I want to be able to go
from the integer arrays start and end to a matrix. The simplest
implementation would probably be:

matrix = zeros(shape)
for i in xrange(len(start)):
matrix[start[i], end[i]] += 1
return out

For performance reasons I've implemented it as:

x = np.ravel_multi_index([start, end], shape)
matrix = np.bincount(x, minlength=np.prod(shape))
matrix.shape = shape
return matrix

Is that clear?

Bago

On Thu, Aug 9, 2012 at 8:36 PM, Stefan van der Walt <
notifications@github.com> wrote:

Sorry, I'm a bit late to the party--can you explain to me why we need
unravel_multi_index in the first place?

—
Reply to this email directly or view it on GitHubhttps://github.com//pull/55#issuecomment-7633479.

[travisbot]

This pull request fails (merged 8c8adaa into 73e8e16).