RF, BF: Implement optimal tau_factor for pca denoising and: fix a bug on the expected functionality of a 3D sigma matrix. Previously, localpca was not exploring the spatial information of the 3D sigma matrix.
RF, BF: Implement optimal tau_factor for pca denoising and:
fix a bug on the expected functionality of a 3D sigma matrix. Previously, localpca was not exploring the spatial information of the 3D sigma matrix.

FrancoisRheaultUS/dipy,FrancoisRheaultUS/dipy