This function calls avscale to get individual
matrices for FSL
fsl_avscale(file, volume = NULL, parsed = TRUE, verbose = TRUE)
avscale(...)(character) matrix filename
(character) non-reference volume filename or nifti image
(logical) should parse_avscale be run
after?
(logical) print out command before running
not used, but used for duplicating avscale as alias
Character of information from avscale