Tagged Questions

Questions on parallel computing in Mathematica.

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2
votes
1answer
86 views

How can I set the kernel for CreatePalette?

I have written some code that requests some calculations from an SQL server every N seconds and uses a palette: CreatePalette[Dynamic[DateListPlot[...]]] I ...
11
votes
3answers
304 views

Suspecting bug in Parallel Framework

I've reduced my actual problem to: ParallelEvaluate[ Module[{slot=1}, Slot[slot] ] ] gives error messages that I think shouldn't be there. It seems I can ...
2
votes
1answer
547 views

3 hour calculation? ParallelMap & ParallelTable

I'm having some problems with slow Mathematica code... I'm basically doing a computation that's is expected to take 3 hours (!) in my Core i7 with 4 processors... I'm basically computing an index (of ...
6
votes
1answer
368 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, ...
7
votes
1answer
234 views

how can I avoid CPU waste (by master kernel) using WaitNext?

I'm using WaitNext in Mathematica for parallel processing on Mac OS X. I have 4 processors on my MacBook and LaunchKernels[] ...
1
vote
1answer
107 views

Draw from HistogramDistribution with ParallelTable

I wanted to check something, but ran into troubles using HistogramDistribution in combination with ParallelTable. The code does the following: Compute a HistogramDistribution of some sample and use ...
7
votes
1answer
223 views

How to make this code threadsafe?

I have the following code, schematically: ...
2
votes
1answer
307 views

Light Weight Grid and core limitation

I am trying to figure out what would be best for running some simulations using multiple computers where each has it's own mma 8 licence. The main part of the computation involves a parallelized table ...
5
votes
1answer
354 views

Progress indicator with shared variables

I'm trying to create a custom progress indicator for a parallelized computation, using Dynamic and SetSharedVariables to display ...
12
votes
2answers
421 views

Tell ParallelMap[] to use just specific kernels

Is there a way to tell ParallelMap to use just some specific kernels (as is possible for ParallelEvaluate)? Background: I have ...
1
vote
0answers
182 views

Parallel linear algebra with arbitrary precision

Is it possible to do parallel linear algebra with arbitrary precision within Mathematica (in a simple manner, as is done for the machine precision)?
3
votes
1answer
267 views

Why can't Mathematica parallelize this?

The following code makes mathematica print "ParallelTable::nopar1: [...] cannot be parallelized; proceeding with sequential evaluation." ...
1
vote
0answers
221 views

Return Functions from parallel execution of module

I wrote a module which numerically solves an ODE using NDSolve. The result from this is e.g. either ...
6
votes
2answers
304 views

Use of Cellular Automaton or Discrete Convolution to calculate Potts Energy of a 2D Matrix

In a project of Monte Carlo Modelling of Grain Growth (Link) one of the most costly subroutines is the calculation of the Potts-Energy of an Monte Carlo Grid cell by comparing the center cell value ...
3
votes
1answer
325 views

using interpolation functions in ParallelMap

Edit I am editing the question to give a simple workable example. It is at the bottom under the heading Example. The original question is now headed withe Background. Background I am trying to ...
4
votes
1answer
265 views

ParallelTable and Precision

I'm using ParallelTable[] to calculate a function over a range of my parameters , ($\omega,\ell$). This seems to be working well (in terms of speed increase) except ...
7
votes
1answer
235 views

Is there a way to convert mathematica code to OpenMP or OpenACC?

I see that Mathematica has limited support for things like OpenCL and CUDA, but what about other standards like OpenMP or OpenACC?
2
votes
1answer
219 views

Clearing distributed definitions from remote kernels

The documentation shows the following example to "Remove a distributed definition..." Oh, course this doesn't work without redefining the function prior to re distributing the definition. The ...
7
votes
1answer
449 views

Communication between parallel kernels

Greetings. This is my first post here, also, I am not a seasoned programmer, so any advice pertaining to coding that is not directly related to the problem (stated below) is welcome. I am having ...
5
votes
1answer
236 views

MapThread and parallel computing

This time I have a very short question. Is there a deeper reason why ParallelMapThread does not exist? Regards, Frink
11
votes
2answers
299 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, ...
15
votes
2answers
1k 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 ...
3
votes
1answer
165 views

How do I fix Needs[“OpenCLLink`”] failure?

In Mathematica 8.0.4 under Mac OS X 10.8.2, when I evaluate Needs["OpenCLLink`"] I get error ...
10
votes
1answer
666 views

Is there a simple example using OpenCLLink that shows performance advantages?

OpenCLLink allows Mathematica to use the OpenCL parallel computing language. I have done some tests on simple examples, but so far, the CPU regularly outperforms ...
3
votes
1answer
582 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 ...
7
votes
0answers
243 views

Using Compile to speed up Function with PermutationProduct

I have the following fairly simple routine dot involving PermutationProduct that I wish to speed up using ...
2
votes
2answers
486 views

Difference between sub MathKernel and MathKernel

When I try to run Mathematica processes in parallel on a Linux based server, I see that my server allows 7 MathKernels and 28 sub MathKernels. I was wondering what the difference is and how I can take ...
5
votes
1answer
251 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 ...
1
vote
1answer
215 views

Version differences in Parallelize

I am having a problem which I guess is due to version difference. I have to generate a list of unitary matrices, which I can do easily. However I came to know about ...
4
votes
0answers
83 views

Mathlink and Parallelization [duplicate]

Possible Duplicate: How to run mathlink external commands in parallel? Abstract I have a binary file compiled to work with MathLink. I can install the file and run the component functions ...
2
votes
1answer
170 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 ...
5
votes
2answers
209 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 ...
15
votes
1answer
530 views

Parallel compiled functions running on parallel sub-kernels

Question Why is it, that compiled, Listable, parallel functions which work perfectly fine on the main kernel, do not run in parallel on sub-kernels? Details ...
6
votes
2answers
184 views

ParallelTable running on outermost index only

I need to run a simple ParallelTable: ...
0
votes
1answer
504 views

On the parallelization of matrix multiplications in Mathematica 8

I have installed Mathematica 8, but I think the commands for parallelizations do not work! Even when I try to test the example in the Help of Mathematica, I face with ParallelDo::nopar: No ...
2
votes
1answer
219 views

how to nest parallelized computations on a cluster?

I am lucky to have access to a computational cluster and I could submit my job to many-many cores. As I need to evaluate a numerical integral within a numerical integral, I would like to know if I can ...
0
votes
2answers
799 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 ...
21
votes
3answers
1k views

Does parallel programming use up large quantities of memory in Mathematica?

When I start Mathematica with a fresh kernel and load a program I am developing to analyze biology data, the amount of used system memory is 1.9 GB (free memory is 14.5 GB). These memory values are ...
13
votes
2answers
808 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 ...
3
votes
3answers
355 views

How can I suppress Print in parallel evaluation?

When using a function that includes Print statements, one can suppress the output by ...
4
votes
1answer
252 views

DistributeDefinitions doesn't work as expected when used for table iterator bounds?

I am new to parallelization in Mathematica, so this question may reflect some elementary confusion. I am attempting to parallelize a rather complicated module which, as part of its internal ...
7
votes
1answer
282 views

Setting $RecursionLimit across all parallel kernels

I'm trying to optimize an elliptic curve factoring method by running it in parallel. There is a recursive step which required me to set the recursion limit higher than 256, however when I try and run ...
30
votes
3answers
2k 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 ...
5
votes
1answer
489 views

Export to file from ParallelDo loop

I currently have a Mathematica code similar to: ...
12
votes
2answers
283 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 ...
31
votes
1answer
951 views

Transferring a large amount of data in parallel calculations

This question is inspired by one of @whuber's answers Consider the following code: ...
6
votes
2answers
596 views

Filling global arrays in parallel calculations

I want to parallelize heavy computations which has to be done many times, the result should be arrays of data. Each calculation does not depend on others (but uses the same variables though). The ...
10
votes
1answer
675 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 ...
10
votes
2answers
1k 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 ...
9
votes
1answer
1k 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 ...