btable.txt is an alias for dsi203_bmax4000, a (nx4) b-table data file used in conjunction with the data set data.nii.gz (alias "DSI 203-point 3mm"), as provided by the Advanced Biomedical MRI Lab, National Taiwan University Hospital, and referenced in the package DSI_Studio developed by Fang-Cheng Yeh.
The first column specifies the b-values, and the remaining 3 columns specify the b-vectors.btable.txt
The sampling points in btable.txt (dsi203_bmax4000) are distributed in a S2 shell with 203 points. The b-values range from 0 to 4000.