box - filter to hypercube
call boxn (nd,center,na,aa,cube)
int(:)
Input data dimension
int(:)
Location of the 1 coeficient in box
int(:)
Dimensions of the filter
C<type(filter)> The filter
real(:)
Output filter values
Convert helix filter to hypercube: cube(na(1),na(2),...)
helix, cartesian, helixcart
geef90