3. Reductions and other transformational intrinsics
Fortran intrinsic procedures operating on whole arrays, often returning array result.
Some just “reshuffle” elements of arrays:
- CSHIFT, EOSHIFT, TRANSPOSE, SPREAD, etc
Implementation similar to array assignments.
Another important class reduces arrays to scalar or lower-rank arrays:
- SUM, PRODUCT, MAXVAL, MINVAL, etc
Communication pattern quite different. Similar to MPI_REDUCE.