Questions on parallel computing in Mathematica.

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18
votes
2answers
2k 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 ...
12
votes
1answer
153 views

DistributeDefinitions and synchronization in Mathematica 10

The command DistributeDefinitions[z] installs all current definitions for z on the local kernels. A simple example: we assign ...
7
votes
1answer
384 views

Launching remote slave kernels on HPC causes slow down

I had a post earlier regarding how I can run Mathematica at a HPC cluster (running PBSpro) by having a single MathKernel launch ...
12
votes
3answers
342 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 ...
10
votes
2answers
198 views

ParallelTable behaves differently when it is run inside a package

I've been butting my head against some very weird behaviour by ParallelTable, and its interaction with packages, over the past few weeks, and making relatively ...
10
votes
1answer
307 views

Using Compile to speed up Function with PermutationProduct [closed]

I have the following fairly simple routine dot involving PermutationProduct that I wish to speed up using ...
7
votes
1answer
40 views

How to ensure that a package is always loaded on startup, even in parallel kernels?

Is there a robust way to ensure that a package is always loaded on startup, even in parallel kernels? Parallel kernels do not read Kernel/init.m.
6
votes
1answer
52 views

Run several input cells in parallel

I have a notebook with several input cells that produce data which is then plotted into separate graphs. Since I do not want to save the results, because it makes the file huge, I keep the ...
5
votes
2answers
310 views

ParallelMap and Sow/Reap - not behaving as expected? [duplicate]

Is ParallelMap and Parallelize@Map expected to work with Sow and Reap construct. This is a rather brief toy code to find all Primes just to force the use of Sow/Reap inside Map ...
5
votes
2answers
221 views

Parallelizing or optimizing a script for calculating the size of all pairwise intersections between collections of sets

I need to speed up or parallelize an operation that looks essentially like this: ...
4
votes
1answer
336 views

Errors when using ParallelTable inside a package

I'm developing a package that contains a function that requires evaluation of an expensive Table, so I use ParallelTable ...
14
votes
1answer
707 views

How to run an external program in parallel with a Mathematica package?

Under Mathematica 8 (Linux x84_64) I was able to run an external program in parallel from a Mathematica package. However this procedure breaks down under Mathematica 9. Within my Mathematica package ...
5
votes
2answers
188 views

Why doesn't ParallelTable work on this very simple example?

For some reason, I'd like to use ParallelTable with a variable number of iterators. Table[a[1], {a[1], 0, 10}] works fine: ...
16
votes
1answer
3k views

Parallelizing Numerical Integration in Mathematica

I have an ugly, six dimensional function that I need to integrate numerically. It works, but it currently take twelve hours to complete the calculation. Is there any good way to parallelize the ...
10
votes
2answers
2k 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 ...
7
votes
2answers
329 views

Communication between local kernels

this is my first post but you have already helped me so many times that I have to start by saying thanks a lot! I have a really long calculation to do, and I have used the Evaluation->Kernel ...
6
votes
1answer
401 views

Is matrix multiplication automatically done in parallel in Mathematica 9?

In good old Mathematica versions (5.2, 6.0), matrix multiplication was automatically done in parallel. For example, on an 8-core machine, define two square real matrices: ...
5
votes
2answers
103 views

Parallel function evaluation for minimal value

I am asking myself, if the evaluation of a function f looking for a minimal value over a discrete set of values can be parallelize (brute scan for a potential ...
5
votes
1answer
288 views

Reap, Sow with Parallelize: bad performance, why?

I have a question about the performance of Reap and Sow with Parallelize. I am aware of the following questions How to collect result continuously (interruptible calculation) when running parallel ...
5
votes
2answers
257 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 ...
4
votes
1answer
102 views

Can a package append its context to $DistributedContexts?

I am writing a package (for reference, this one) which I use extensively in parallel computations, and to lighten the coding load on the 'run-time' notebook, I want my package to sit on the ...
4
votes
0answers
77 views

ParallelTable slow down, Region functions

I am experiencing speed issues with ParallelTable. There are a few related problems on SX posted here and here, but no resolution. The various respondents to those ...
3
votes
1answer
652 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
623 views

How can I suppress Print in parallel evaluation?

When using a function that includes Print statements, one can suppress the output by ...
2
votes
1answer
315 views

ParallelTable and DistributeDefinitions

I have a function in the following form: function[...] := With[ {...}, Table[ anotherfunction[i, j, ...], {i, ...}, {j, ...}, ... ] ] If ...
2
votes
1answer
211 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 ...
8
votes
1answer
208 views

Experimental`NumericalFunction in NMinimize solution

I try to make a number of optimizations using this code: ...
7
votes
1answer
485 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
710 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 ...
6
votes
1answer
854 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 ...
5
votes
1answer
147 views

memory leaks using NIntegrate on parallel kernel

Bug fixed in version 10.2.0 I'm running a large computation in parallel and the memory usage of the parallel kernels is increasing with every iteration of the calculation. Neither ...
5
votes
1answer
213 views

Parallel evaluation of Image and Rasterize problem

The following command: ParallelTable[Image[Graphics[{{Red, Disk[{5, 5}, 4]}}]], {i, 10}] shows a very strange behaviour. It starts a new Mathematica process on ...
5
votes
0answers
183 views

Raster with ColorFunction is blank when Dynamic Updating is disabled

UPDATE Today I was having these WaveletScalogram problems again. I think this is ultimately some kind of interaction issue with Dynamic. I have narrowed it down to ...
5
votes
1answer
302 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 ...
4
votes
1answer
64 views

InstallJava on a parallel kernel while debugging in Wolfram Workbench

Here's my problem. I need to create a link between a client that is a parallel Wolfram kernel and a server through a Java API. I'm using Wolfram Workbench in debugging mode (like most of the time ...
4
votes
2answers
774 views
3
votes
1answer
119 views

Why is $ProcessorCount not equal to LaunchKernels[ ]?

Normally, number of $ProcessorCount should be the same as LaunchKernels[], but if they are not the same, what is the problem? ...
3
votes
1answer
86 views

Why doesn't my expression evaluate at the subkernel?

Consider this code: ...
3
votes
2answers
134 views

How to share numbered variables between kernels

Supose I have two variables v[1] and v[2]. I used: SetSharedVariable[{v[1], v[2]}] Then, ...
3
votes
1answer
307 views

Issue in ParallelTable after evaluating another function using NDSolve and FindRoot. What is wrong with this inverse?

I am trying to find the inverse of a function which is defined through NDSolve and NIntegrate. The question is pretty similar ...
3
votes
1answer
405 views

Why can't Mathematica parallelize this?

The following code makes mathematica print "ParallelTable::nopar1: [...] cannot be parallelized; proceeding with sequential evaluation." ...
3
votes
1answer
330 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 ...
2
votes
0answers
81 views

Is there a way to specify which kernel is used to import files (SOLVED)?

Following up on a previous question in which I encountered a memory leak in the JSON importer I have created a SandBox script that will run the Import and analysis on a separate kernel, which be ...
2
votes
1answer
184 views

SSH known hosts in Windows (Error code = 124)

I had to re-install Raspbian OS and now it has new SSH key. SSH clients usually let ignore this fact and save the new key, but not now. Mathematica gives no way to go if the Host Key was changed. I ...
2
votes
0answers
146 views

Whether NIntegrate evaluation is multithreaded or not?

About MultiThread evaluation I am talking about here, see this post I am NIntegrate the function grarm[e, 3, dimension, 1, 1, 0.005]. There is matrix operation in ...
2
votes
1answer
248 views

Parallelization of REvaluate[]?

Is there a way to run several RLink computations via REvaluate[] in parallel, e.g. with ParallelTable[]?
1
vote
1answer
73 views

Break out of ParallelDo

In a parallelised computation, I would like each kernel separately to break out of ParallelDo when it has finished going through the loop once. For a single kernel ...
1
vote
1answer
43 views

$IterationLimit and parallel computing

Short question: How can you set $IterationLimit for parallel computation? I thought just setting $IterationLimit = Infinity ...
1
vote
1answer
150 views

ParallelTable of ParametricNDSolve objects fail

There seems to be a problem with ParametricNDSolveValue togeteher with ParallelTable First we create a ParametricNDSolveValue object ...
1
vote
0answers
161 views

Why doesn't ParallelMap improve the performance of FoldList?

This question arose during my analysis of the following problem: filling gaps. (The code used here is Simon Woods's work.) FoldList seems to not cooperate with ...