Recent content by Telemachus

Hi. Doesn't interference effects account as photon-photon interaction? I think you mean something like pair creation, but wouldn't a simple double slit interference phenomenon account also as a photon-photon interaction? thanks.

Great answers. Thank you all.

I tried to think why Ampere's law seems to fail in this case. For me it was clear that there is no symmetry in the z direction, there is no translational symmetry because of the finiteness of the wire. On the other hand, I know that Ampere's law is independent of the loop we take. This also...

Ok. Only one thing just to be clear, it is not my code, I've found it on the internet.

I have found the bug. It is a very silly thing, the sweep was calling array elements outside of bounds.

I actually have checked (the last code prints those values), and gives ierr=0 in all calls, which is ok. However, the problem is now in the first call to the subroutine sweep1d, which doesn't have any mpi call.

Ok. I modified the code a little bit. The idea is more or less the same. However, soemthing is happening. Now the error comes from the subroutine sweep1d. What is baffling is that if I comment the first call to sweep1d in the iteration loop, the program runs without any errors. However, if the...

You say that instead of calling "s" in the subroutine I should call h=s-3, for example? the original program uses "s" and "e" as the argument in the subroutine call, and then sends and receives s-1, and e+1. I have tried to use exactly the same idea, but it is not working. I really don't...

I have defined the extended arrays when I call the other subroutine, and the problem persists: program main ! include "mpif.h" integer maxn parameter (maxn = 1024+6) double precision a(maxn,maxn), b(maxn,maxn), f(maxn,maxn) Why it doesn't correspond to an...

Hi. I'm trying to parallelize my code. I am new at MPI, I'm learning the basics. I want to use a domain decomposition strategy in my code. I've been reading a bit, and wanted to use this subroutine to exchange points between neighbors. I've started by trying to modify a code presented by Gropp...

Great. Thank you. How do you know all of these things about how the compiler does the optimization? is there any reference, a book or something that explains all this?

Great. Thanks. I think I can rearrange things to use forall. There was an slight improvement in the code after changing some do loops for this statement. This was the running time after changing some do loops by forall: 2797.387 seconds. And the time without those changes: 2964.344 seconds...

But should it work? or there is a problem with it?

forall(ja=1:N) call calcr(xc(ja),yc(ja),ja,rIp) fxp(:,:,ja)=fx(:,:) fyp(:,:,ja)=fy(:,:) end forall If instead I use: do ja=1,2*mang call calcr(xc(ja),yc(ja),ja,rIp) fxp(:,:,ja)=fx(:,:) fyp(:,:,ja)=fy(:,:) enddo I have...