Dear MRtrix3 experts,

I have a question regarding the tensor fitting process for analyzing diffusion maps, specifically about how it differs between single shell and multishell data.

According to the mrtrix3 manual, I understand that tensor fitting is achieved by first applying Weighted Linear Least Squares (WLS) followed by Iterated Weighted Linear Least Squares (IWLS).

DWI data I am working with consists of images acquired at eight b-zero, b=800 and b=2800 (with 30 directions each), and I intend to calculate FA, ADC, AD, and RD using these images.

In this case, does the fitting process primarily utilize the lower b=800 data only, or if both shells are used for tensor fitting, could you explain how this fitting is conducted?