> Hi numpy. > > Does anyone know if f2py supports allocatable arrays, allocated inside > fortran subroutines? The old f2py docs seem to indicate that the > allocatable array must be created with numpy, and dropped in the module. > Here's more background to explain... > > I have a fortran subroutine that returns allocatable positions and > velocities arrays. I wish I could get rid of the allocatable part, but you > don't know how many particles it will create until the subroutine does > some > work (it checks if each particle it perturbs ends up in the domain). > > module zp > implicit none > contains > subroutine ics(..., num_particles, particle_mass, positions, velocities) > use data_types, only : dp > implicit none > ... inputs ... > integer, intent(out) :: num_particles > real (kind=dp), intent(out) :: particle_mass > real (kind=dp), intent(out), dimension(:, :), allocatable :: > positions, > velocities > ... > end subroutine > end module > > I tested this with a fortran driver program and it looks good, but when I > try with f2py, it cannot compile. It throws the error "Error: Actual > argument for 'positions' must be ALLOCATABLE at (1)". I figure this has > something to do with the auto-generated "*-f2pywrappers2.f90" file, but > the > build deletes the file. > > If anyone knows an f2py friendly way to rework this, I would be happy to > try. I'm also fine with using ctypes if it can handle this case.
Can you split your code so that you have a subroutine which calculates the number of particles only, and call this subroutine from your 'original' routine? If yes, then you might be able to say somehting like real (kind=dp), intent(out), dimension(get_particle_number(WHATEVER) :: Not entirely sure, though ... Can someone with more f2py knowledge confirm this? _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
