Transforming bvecs after registration

[weningerleon]

Hi,

I'd like to co-register two different raw diffusion images with an affine transformation.
Currently, I'm registering these using FA maps, and then applying the transform to all diffusion images.
How do I then apply the transform to the bvecs? I couldn't find any function for this in dipy.
My best guess would be this, but as I can't really verify the result, I would be very grateful for a second opinion:

bvecs_new = np.matmul(affine[0:3,0:3], bvecs.T).T

[arokem]

Does this do what you want? https://github.com/dipy/dipy/blob/master/dipy/core/gradients.py#L447-L501

[weningerleon]

Perfect, I didn't find this function.
Thanks!