! This file: http://ftp.aset.psu.edu/pub/ger/fortran/hdk/PackPick.f90
!
! molagnon@ifremer.fr (Michel OLAGNON)
! F-Compiler compatible.
program packpick
integer, parameter :: DP = selected_real_kind(15)
real(kind=DP), dimension(5) :: X
integer :: i

X=0
X(1)=1_DP
X(3)=3_DP
print *, "Vector subscripts of X where X is non-zero are:"
print *, "Results of the next line should be indices 1 and 3."
print *, pack((/(i, i = 1,size(X))/),(X /= 0))

end program packpick