# dirmerge¶

## Synopsis¶

Splice / merge multiple sets of directions in such a way as to maintain near-optimality upon truncation

## Usage¶

dirmerge [ options ]  subsets bvalue files [ bvalue files ... ] out

• subsets: the number of subsets (eg. phase encoding directions) per b-value
• bvalue files: the b-value and sets of corresponding files, in order
• out: the output directions file, with each row listing the X Y Z gradient directions, the b-value, and an index representing the phase encode direction

## Options¶

• -unipolar_weight set the weight given to the unipolar electrostatic repulsion model compared to the bipolar model (default: 0.2).

### Standard options¶

• -info display information messages.
• -quiet do not display information messages or progress status; alternatively, this can be achieved by setting the MRTRIX_QUIET environment variable to a non-empty string.
• -debug display debugging messages.
• -force force overwrite of output files (caution: using the same file as input and output might cause unexpected behaviour).