This is a complicated file format that we made up in order to allow for a “point-and-click” interaction with structural connectomes on the HCP Workbench, but we don’t have FSL tools for reading it out (there is C++ code for that but no user interface).
Briefly, this format stores multiple informations in every cell of a sparse matrix (number of streamlines, length of the streamline, proportion of stick orientations that were sampled in each voxel).
In any case, this matrix doesn’t quite store what you are after, which as I understand is more of a 3D array (seedsXseedsXbrain) ?
> On 9 Aug 2017, at 15:15, Maxwell Bertolero <[log in to unmask]> wrote:
> Does anyone know how to read the outputs of probtrackx2 (matrix4) .mtx files? I want to know, for each pair of seeds, the number of tracts between them and the voxels the tracts cross through.
> Max Bertolero