Questions on parallel computing in Mathematica.
18
votes
1answer
371 views
Transferring a large amount of data in parallel calculations
This question is inspired by one of @whuber's answers
Consider the following code:
...
12
votes
6answers
612 views
Efficient conditional Mean[] on a large data set
Consider a list, AK6, that has 382 sublists of length varying from 2500 to 3000. Each "subsublist" is as such : ...
13
votes
4answers
483 views
How to collect result continuously (interruptible calculation) when running parallel calculations?
This is the most common pattern to compute a table of results:
Table[function[p], {p, parameters}]
(regardless of how it's implemented, it could be a ...
7
votes
2answers
397 views
ParallelTable and Table do not give same result
I have a question regarding the use of Parallelize.
In the help one can read that “Parallelize[Table[expr,iter, …]] (which is ...
31
votes
4answers
1k views
Speeding up this fractal-generating code
I used the code below (which is a sample from this gist containing more similar code) in my answer to my own question about Mandelbrot-like sets for functions other than the simple quadratic on ...
11
votes
2answers
462 views
How to run mathlink external commands in parallel?
I have an external function called increment (for the sake of illustration) that I call from Mathematica using MathLink. I.e.,
...
13
votes
3answers
574 views
Monitor doesn't work with ParallelTable
I can't monitor ParallelTable:
Monitor[ParallelTable[Pause[3]; i, {i, 1, 10}], i]
just displays i until it is finished.
Do ...
10
votes
1answer
347 views
Nesting Parallel processes
I just attempted to run code that had nested ParallelMap[] functions. It generates the error message:
ParallelMap::subpar: Parallel computations cannot be nested;
proceeding with sequential ...
8
votes
1answer
736 views
Wolfram Light Weight Grid and parallel computing
I have attempted to set up and use the Wolfram Lightweight Grid Manager so I can do parallel computing from Mathematica using 2 remote processors on another machine on my local network.
My ...
26
votes
4answers
1k views
Is it possible to speed up ContourPlot on multi-core machines?
It is not very difficult to face a function for which ContourPlot works too slow. And it seems natural that this function can be parallelized well. Anyway, naive ...
10
votes
5answers
520 views
Connecting to and disconnecting from a continuously running kernel, on demand
I realized that there are lots of advantages to driving C/C++/FORTRAN code directly from Mathematica as LibraryLink functions (instead of running them from the command line or a shell script, as I ...
11
votes
2answers
558 views
Speeding up random walk for many particles
I am trying to speed up this code for many particles to take a random walk. I'm not sure why it is so slow for such a simple task.
I got a few hints from colleagues to reduce the precision of the ...
24
votes
3answers
820 views
Are built-in Mathematica functions already parallelized?
I've been noticing something strange since updating to Mathematica 8, and that is that occaisionally I'll see that the MathKernel is using up to 800% CPU in my Activity Monitor on OS X (I have 8 ...
17
votes
2answers
312 views
Parallelize evaluation of function with memoization
I have a complicated function that I need multiple times, so I want to memoize it and have the first evaluation done in parallel. Unlike in my example below it's not a continuous function, so ...
15
votes
2answers
602 views
Parallelization problem in LinearSolve and Minimize
My CPU has got 8 cores (it is Intel Core i7-2600 3.40 GHz). When I try to solve a linear matrix equation using LinearSolve for large matrices, Mathematica just uses 4 cores to solve the problem (CPU ...
7
votes
2answers
164 views
Mathematica Parellelization on HPC
I'm currently using Mathematica on a High Performance Cluster (HPC) which consists of many compute nodes each with around 16 cores. I currently run my Mathematica script on 20 of the nodes that ...
12
votes
2answers
232 views
Parallelization of distinct array write access from subkernels
I'm working on an implementation of a multivariate FFT, which is (or at least should be) highly parallelizable due to the row-column-algorithm. However, i can't figure out how to implement that. The ...
9
votes
2answers
124 views
Package found with `Needs`, but not with `ParallelNeeds`
I want to use a self-written package in a parallel computation. However while Needs["mypackage`"] works without problems, ...
9
votes
2answers
851 views
CUDA and GPU hardware and compatibility questions?
We have iMac desktops and have just begun to parallelize computations across them see: Wolfram Light Weight Grid and parallel computing.
This still does not look like it will give us the performance ...
3
votes
1answer
400 views
Are there any openCL test suites?
I have a new ATI gpu that I have been trying on 3 different distributed computing projects. I get errors on each work unit.
The errors indicate No Protocol which could be caused by a bad environment ...
3
votes
3answers
179 views
How can I suppress Print in parallel evaluation?
When using a function that includes Print statements, one can suppress the output by
...
6
votes
1answer
221 views
Export graphics in parallel
I run a heavy simulation, using NDSolve and the method of lines. This means that the result of NDSolve is a list of, say, ...
6
votes
1answer
280 views
Efficiency of ParallelDo when a global variable./matrix is being updated
(Disclaimer: I realize that the addition of matrices a and b below can be done very fast just by typing a+b. The code below is just meant to illustrate behavior similar to what I observe in much more ...
6
votes
1answer
191 views
PrintTemporary in ParallelTable
I thought of a possible answer to Monitor doesn't work with ParallelTable but it doesn't work as I hoped it would.
This accumulates print cells instead of deleting them as intended. Can it be ...
5
votes
1answer
167 views
Build recursion in parallel?
Problem
Let's define a simple recursion.
f[1] = 1;
f[n_] := f[n] = f[n - 1]*n;
If I evaluate f in parallel
...
5
votes
2answers
135 views
Computers running Wolfram lightweight grid manager won't fall asleep
I have a computing environment comprised of:
27" iMac with dual cores running Mac OS X 10.6.8 and
2 XServes each with 2 quad cores running Max OS X Server 10.6.8
All networking by ethernet to a Time ...
2
votes
1answer
107 views
Server running WolframLightWeightGrid manager loses licensing information
"Once more into the breach..,"
I have 2 identical Xserves running OS X Server 10.6.8 each with 2 quad core Intel Xenon processors a total of 16 kernels. I have configured both servers identically ...
0
votes
2answers
432 views
nested numerical integration: not valid limits?
I encountered an error when I was hoping for some Mathematica (8.0.4) magic sparing me to code up numerical integration, function approximation and root-finding myself. The broader context and the ...
