shfit - Fits the spherical harmonic series to the log measurements.
SYNOPSIS
shfit
[options]
DESCRIPTION
Fits the spherical harmonic series to the apparent diffusion coefficient profile. The
program computes d = -1/b log(A(q)/A(0)) for each measurements and fits the series to d
as a function of q/|q|. The output of the operation in each voxel is the array [exitCode,
log A^tar(0), c00, c20, Re(c21), Im(c21), Re(c22), Im(c22), c40, Re(c41), Im(c41),
exitCode indicates the success of the operation and should be zero if everything worked
OK; A^tar(0) is the best fit MRI signal at b=0.
Fitting the spherical harmonic series is not particularly useful on its own. More useful
it to use the spherical harmonic series for voxel classification, see voxelclassify(1).
The anisotropy of the spherical harmonic fit, which sfanis(1) can compute, is a useful
alternative to the fractional anisotropy, fa(1), which takes into account departures from
Gaussian displacements.
EXAMPLES
Fit the fourth-order spherical harmonic series to some synthetic data with two dominant
directions: