Recent content by davidfur

I know even less about pthreads...

Thanks, but I don't think I understand the problem. Here is the dista3 subroutine, which calculates the distance: subroutine dista3 (n1,pos,dista,dx,dy,dz) include 'cbka.blk' double precision :: pos(3) !********************************************************************* ...

Why not, Vanadium?

Hey guys, I've started to read some OpenMP programming and now I'm trying to parallelize small part of a fortran code. The first thing I would like to do is to parallelize the innermost DO loop. It loops through the number of particles (na) and calculates the distance between some point in 3D...

Wow. This works like magic! I've never heard about "lambda" before! this is exactly what I needed to overcome the "barrier" in transferring member functions to general functions. Though, I wonder how else this could be done without the lambda trick... Thanks Filip!

Hey guys, I have written a C++ code which is based on two main classes: Particle and Group. Each Group contains a set of Particle(s), each Particle is defined by a set of coordinates, and has an associated energy and force (the energy/force evaluation is done by calling an external program). I...

Hey guys, I parallelized my code, written in C++, with the MPI library. Unfortunately, the speed-up I get saturates at x6, with increasing number of cores. Whereas, in theory, the speed-up should really be nearly linear. To understand where the bottlenecks come from, I drilled down the code to...

Thanks Mark44 for your help! I managed to solve the problem by properly declaring and allocating coords and gradvec variables outside the get_energy_and_grad subroutine. Cheers!

Thanks jedishrfu, but it doesn't work either. I suspect there's something wrong with my declarations... I post here the full code if this helps Main program program main use reaxff_interface implicit none integer natoms_ real*8 ereal real*8, allocatable :: coords(:,:) real*8, allocatable ...

Hi guys, On with my Fortran adventures...I'm trying to accomplish a simple task: assign a 2D array with some reals. Here's an excerpt from the code: subroutine get_energy_and_grad(natoms_,coords,ereal,gradmat) include 'cbka.blk' include 'opt.blk' integer, intent(in) :: natoms_...

DrClaude: Thanks! following your words, I now understand what I was doing wrong. The trouble was that I was using the dbl variable inside my_sub as if it was passed by reference from the module (without adding use my_mod). When I did add use my_mod to my_sub, and removed the declaration of dbl...

If that is the reason, then it's a bit weird...because I did include use my_mod in main.f90, and directly calling double_coords didn't work either. Returned same answer as with the my_mod route.

DrClaude: and why's that? Do i need to write an INTERFACE statement in the beginning of my_mod to make the subroutine access the module variable dbl? jedishrfu: I also tried calling double_coords directly from main.f90, but still all I see is 0.0000, 0.0000, 0.0000

Right. First of all, I converted all the f77 sources to f90 sources with f2f (https://bitbucket.org/lemonlab/f2f/). Now to the actual interface part. Just to begin to understand how these things work, I've built three example files (main.f90, my_mod.f90 and my_sub.f90). Let's suppose that...

Hi jedishrfu Thanks for your answer! That's probably a good idea, I'll look into the links you provided. So, in your opinion what would be a good strategy for this kind of interface? i.e. building in interface between two independent programs (suppose they are both f90) ? And, what about when...