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by Dcole
March 9th, 2011, 8:56 pm
Forum: Numerical Methods Forum
Topic: CUFFT vs FFTW
Replies: 0
Views: 25649

CUFFT vs FFTW

<t>Hello all..been a while since I posted here, but I figured you all might be able to help me figure something out.I am working a DSP code that was written using FFTW, but I am trying to use CUFFT, which is the cuda FFT library.I wrote a simple test program, where I was doing Complex to Complex FT'...
by Dcole
August 5th, 2010, 6:35 pm
Forum: Numerical Methods Forum
Topic: PCG discussions
Replies: 13
Views: 29702

PCG discussions

<t>Hello all,I am doing some research on the PCG algorithm, because I have been tasked with optimizing one at work. I was able to do this on the serial version by storing the sparse matrix in CSR which greatly sped up the matrix vector multiplication and was great for the serial version of this algo...
by Dcole
July 6th, 2010, 5:23 pm
Forum: Numerical Methods Forum
Topic: Sparse matrix with different boundary conditions
Replies: 14
Views: 29472

Sparse matrix with different boundary conditions

<t>I think I have that part figured out. I am now onto a different problem with this solver, related to option 2(treat dirichlet as constants).In the solver I am working on, the sparse matrices are stored in coordinate form. Basically for every row there is a set of coordinates corresponding to the ...
by Dcole
June 25th, 2010, 1:52 pm
Forum: Numerical Methods Forum
Topic: Sparse matrix with different boundary conditions
Replies: 14
Views: 29472

Sparse matrix with different boundary conditions

<t>I think I just figured something out. The only real boundary condition that messes me up is Dirichlet. Setting the boundary to a constant is the only one that I am not sure how to represent in the sparse matrix. I suppose I could assume that ALL rows in the matrix would have 7 non zero values, an...
by Dcole
June 25th, 2010, 12:30 pm
Forum: Numerical Methods Forum
Topic: Sparse matrix with different boundary conditions
Replies: 14
Views: 29472

Sparse matrix with different boundary conditions

<t>I will see what I can do - I dont have matlab on this system at work, so it would be hard to generate a picture (unless you know of an online tool?).I think i see what you are saying though - when possible, store in ELL, when not, store in COO.This is kind of what I envisioned as well, I just hav...
by Dcole
June 24th, 2010, 7:39 pm
Forum: Numerical Methods Forum
Topic: Sparse matrix with different boundary conditions
Replies: 14
Views: 29472

Sparse matrix with different boundary conditions

<t>It is not a moving boundary problem. It is just a 7 point stencil problem. Each of the boundary conditions is set at runtime for xmin, xmax, ymin, ymax, zmin, zmaxIf I were going to try to force this into a scheme, should I just go with COO only? That paper you cited was saying that the hybrid wo...
by Dcole
June 24th, 2010, 6:13 pm
Forum: Numerical Methods Forum
Topic: Sparse matrix with different boundary conditions
Replies: 14
Views: 29472

Sparse matrix with different boundary conditions

btw - to be clear, i dont care about space usage for this problem, just solving the cache-locality problem
by Dcole
June 24th, 2010, 6:12 pm
Forum: Numerical Methods Forum
Topic: Sparse matrix with different boundary conditions
Replies: 14
Views: 29472

Sparse matrix with different boundary conditions

<t>The boundary conditions could be a mix of Neumann, Reflective, Dirichlet. I guess that is one way of doing it though, assume they are all Neumann, do the solve as if it is symettric, then go back in and clear the values that are on the boundary, and then recompute those to be dirichlet or whateve...
by Dcole
June 24th, 2010, 3:20 pm
Forum: Numerical Methods Forum
Topic: Sparse matrix with different boundary conditions
Replies: 14
Views: 29472

Sparse matrix with different boundary conditions

<t>Hi All.I am trying to solve a PDE using an iterative method, and I am trying to store the 3D space into a sparse matrix. I am having trouble understanding one concept though. The 3D space I am working on can have several different (or all the same) boundary conditions at each of the 6 faces of th...
by Dcole
April 5th, 2010, 6:53 pm
Forum: Numerical Methods Forum
Topic: Residual in 3D Gauss Seidel
Replies: 1
Views: 30977

Residual in 3D Gauss Seidel

<t>Greetings all,As some of you have seen in my previous post, I have been working on a 3D Gauss Seidel solver for quite some time. I have managed to parallelize the solver finally after getting all of the memory issues in the code worked out. However, there is one slight problem. I think that the r...
by Dcole
March 7th, 2010, 3:08 pm
Forum: Numerical Methods Forum
Topic: MPI subarray problem
Replies: 7
Views: 32823

MPI subarray problem

I am fitting this in to a previously, and poorly, written G.S. solver. It is actually working in a 3D domain, so I am red-blacking each "slice" for now, then stuffing it back into the slice of the full 3D domain. Is there perhaps a better way?
by Dcole
March 6th, 2010, 11:21 pm
Forum: Numerical Methods Forum
Topic: MPI subarray problem
Replies: 7
Views: 32823

MPI subarray problem

I will check these suggestions out when I get to work on monday. I dont have the MIPS compiler here that I was using to test this. Sounds like using a structure is going to be thew ay to go
by Dcole
March 5th, 2010, 10:03 pm
Forum: Numerical Methods Forum
Topic: MPI subarray problem
Replies: 7
Views: 32823

MPI subarray problem

please excuse any typos. I dont have a C-compiler on this computer, so I had to type this in from memory!
by Dcole
March 5th, 2010, 10:02 pm
Forum: Numerical Methods Forum
Topic: MPI subarray problem
Replies: 7
Views: 32823

MPI subarray problem

<t>Hi all. I am still working on parallelizing that red-black G.S. solver that I previously mentioned in another thread. I am having a problem with a little test program I am developing to help with integration into our main program. I want to be able to "extract" a sub-matrix from a larger 2D matri...
by Dcole
January 26th, 2010, 9:55 pm
Forum: Numerical Methods Forum
Topic: Dynamic ADI
Replies: 42
Views: 44982

Dynamic ADI

<t>QuoteOriginally posted by: mblattrichardlm, thanks a lot for backing me up.If someone needs more info about parallel AMG you might want to look at this Parallel AMG overview paper.BTW: DUNE (templated C++ library for solving PDEs) has a parallel AMG method, too. (On my Dell e6400 laptop, I solve ...
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