Fits an axial distribution to some vector data. The output is the parameters of the
Bingham, Watson, or ACG distribution fitted to the data. Either the concentration
parameters alone, or the complete PDF in the format of picopdfs (see picopdfs(1))
may be outputted.
The input data should be cartesian vectors in raw binary format: [x y z x y z...x y z].
EXAMPLES
Fit the concentration parameters of the Bingham distribution to a set of axes in the file
test/axes.Bdouble, and send the concentration parameters to stdout as text
axialdistfit < test/axes.Bdouble | double2txt
Fit the parameters and output the eigenvectors of the PDF as well as the concentration.
Specifies the PDF to fit to the data. Default is Bingham.
-outputpicoformat
Output the entire PICo PDF, including the eigenvectors of the distribution. See
picopdfs(1).
-evecs <theta_1phi_1theta_2phi_2theta_3phi_3>
When specified with -outputpicoformat, outputs the specified eigenvectors instead
of the eigenvectors of the scatter matrix of the samples.
-vectorspervoxel <num>
If this is specified, the program fits the axial distribution to blocks of num
vectors. By default, all the vectors in the input are considered to be a single unit.
-bgmask <Mask file>
A binary brain / background mask. The mask file contains zero in background voxels and non-zero in
foreground. The mask may be a NIfTI image or in raw format, if raw it is assumed to be of type "short".
-maskdatatype <char|short|int|long|float|double>
Specifies the type of the mask file; must be big-endian byte ordering. Ignored for NIfTI masks.