Gather(const DAD* dst, const DAD* src, const int len,
const DAD* subs [], const int* subsDat [],
const DAD* msk, const int* mskDat)
The source array is described by the DAD *src and the
destination array is described by the DAD *dst.
len specifies the size of each array element, in bytes.
The vectors subs and subsDat have extent R--the rank of
the source array. The subscript arrays are defined by the pairs
*subs [r], subsDat [r]. If msk is
non-null, the pair *msk, mskDat defines a mask array.