If you use EXPOKIT, note that there are some small bugs in some of its code which can cause integer overflow and lead to wrong results.
For example, in dgpadm.f, around line 87
Originally it is
scale = t / DBLE(2**ns)
that 2**ns will cause integer overflow if ns>30 if the default integer type is integer 4, then the DBLE(2**ns) will be something like NAN. You need to change DBLE(2**ns) to something like 2.0d0**ns
Without this fix, every time if ns>30, dgpadm will just output wrong results like NAN or something.
Basically any DBLE() in those code in EXPOKT need to be carefully checked to prevent integer overflow issues.