! make shared library calcdist.so by typing: ! gfortran -O3 -shared -fPIC calcdist.f90 -o calcdist.so subroutine calcdist(no_nucl,no_struct,pairing_data,distance) implicit none integer, intent(in) :: no_struct, no_nucl, pairing_data(no_struct,no_nucl,no_nucl) integer, intent(out) :: distance(no_struct,no_struct) integer :: i,j distance = 0 do i = 1, no_struct do j = 1, no_struct distance(i,j) = sum(abs(pairing_data(i,:,:)-pairing_data(j,:,:))) end do end do end subroutine calcdist