"x"|"n"
,<qmax>,<qsig>,<rmin>,<rmax>,<np>
This command allows the user to allocate space when just calculating
a PDF. The first three parameters are similar to 'read data' and
the next three parameters specify the range in r to be from <rmin>
to <rmax> and the number of points <np>. Note that this command
allocates the space for one data set without actually reading any
data ! Use the command 'reset' before reading "real" data for a
refinement.