This program reads in a GE cdiflist and outputs gradient file + file
of bvalues, which can be used in subsequent processing.

Ver  : 0.3
Date : June 22, 2020
Auth : PA Taylor


+ cdiflist (from GE DWI scanning)
+ max bvalue used (in using s/mm^2), e.g., 1000 or 1100.


+ row gradient file (unscaled, unit-magnitude)
+ col gradient file (scaled by b-magn)
+ row bval file     (bvalues)


-cdiflist CDIFLIST
               :(req) name(s) of cdiflist text file, which can be
                output by GE scanners when acquiring DWIs and has the
                following format:
                + first line is 1 number, which is the number of grads N
                  used in the aquisition
                + N rows of 3 values each, which relate to the gradient
                  direction+strength (but they are *not* directly the
                  grads themselves)

-bval_max BBB  :(req) max bvalue used, which provides a reference value
                for scaling everything else

-prefix PP     :(req) output basename for the subsequent grad and bvalue
                Note that this can include path information, but both
                a suffix and a file extensions will be added for the
                main outputs:
                   _rvec.dat  (row-format of gradients, unit magn)
                   _bval.dat  (row-format of bvals)
                   _cvec.dat  (col-format of grads, scaled by b-values)

-ver           :display current version

-date          :display release/editing date of current version
                (June 22, 2020)

-help          :display help (in terminal)
-h             :display help (in terminal)

-hview         :display help (in separate text editor)


At this point in time, this program should only be used if the DWI
acquisition used *axial slices*.  This tends to be (by far) the most
common way to acquire the data, so this probably isn't a very
prohibitive restriction.  However, more option(s) would need to be
added for dealing with other slice acquisitions (based on how GE
stores the data).

Also, if you have any questions/uncertainty about the gradient info,
just ask.  And if you *really* want a correct answer, of course you
should ask Joelle, the real expert!

EXAMPLES             \
    -cdiflist  cdiflist45                \
    -bval_max  1100                      \
    -prefix    grads_ge_45