-dirs parameter for dwi2response

Hello everyone,

I am looking to use the manual parameterization of dwi2response function.
dwi2response manual input in_voxels output -dirs …
Is there any MRTRIX Function that provides the (X Y Z 3) directions of the
needed voxels by the tensor for the -dirs input?
More specifically, in my understanding it is right to use in this case:
tensor2metric tensor.mif -vector dirs.mif for calculation of the principal eigen-
vector, hence, the main directionality. Or this is not what is required as input?

Thanks a lot!

Yes, you can certainly use tensor2metric -vector for that. I’d also add the -modulate none option to make sure they’re all unit length – I can’t remember whether the approach performs normalisation internally…

Perfect, thanks a lot for the answer!