Questions on parallel computing in Mathematica.

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2
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0answers
68 views

How can you link Parallel Mapping and Error tracking

Following this question and the comments made, together with the information in this question, the following code allows error tracking and debugging very nicely. ...
7
votes
2answers
474 views

Writing data to a common file during parallel processing

I am executing a loop, and in each loop I have to store a parameter in a file. It is like ...
1
vote
0answers
137 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 ...
4
votes
2answers
114 views

ParallelTable with nonstandard iterator

This works as expected: Table[x[1], {x[1], 1, 10}] However, the parallel version ParallelTable[x[1], {x[1], 1, 10}] ...
2
votes
0answers
121 views

correct usage of ParallelTable

I am trying to parallelize my script. Here is a MWE of how I have done it: ...
6
votes
2answers
220 views

Does Eigenvalues evaluate in a parallelized way?

I use mathematica on a computer with linux operating system. The computer has 2 cpus and each cpu has 4 cores, so there are totally 8 cores available. Now I got confused with whether the evaluation ...
8
votes
2answers
212 views

Distribute and analyze large datasets

I need to analyze very large datasets, and they obviously don't fit in a computer memory. I need to produce some statistics on these datasets, and this brings me here: How can I make some statistical ...
10
votes
1answer
429 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 ...
9
votes
3answers
312 views

Why is this parallel evaluation with Dispatch[] so slow?

Can you efficiently parallelize this? The parallel versions are much slower than the sequential version, and I'm not sure why. Does SetSharedVariable allow ...
3
votes
0answers
141 views

Mathlink and multithreading

In order to make my computations faster I have developed a C/C++ application calling Mathematica kernel and performing many operations using Mathematica functions for equation solving. Now I want to ...
5
votes
0answers
196 views

Parallelizing is much slower than single kernel evaluation?

Starting with a vector of matrices, tVec, I would like to parallelize the multiplication of each element with the same matrix ...
4
votes
0answers
139 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 ...
2
votes
1answer
189 views

Mathematica 7: Problems when evaluating Fourier inside a ParallelTable

after I got such a great response for my first question on this site, I'm very encouraged to asked my second one! So here it is, very generally: To speed up a "row-wise" (i.e. 1D) operation on a ...
2
votes
1answer
224 views

How can I prevent these warnings while using ParallelTable

I have this code to find all the permutations of a set of letters that form legal words. ...
6
votes
1answer
237 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 ...
7
votes
3answers
349 views

Efficient way to utilise Parallel features to make use of many cores

Let's say I have 100 cores/kernels as my disposal and want to compute a function of two variables f[x,y] over {x,1,10}, ...
2
votes
2answers
153 views

Parallelization of REvaluate[]?

Is there a way to run several RLink computations via REvaluate[] in parallel, e.g. with ParallelTable[]?
12
votes
3answers
594 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 ...
2
votes
1answer
127 views

Mathematica 9.0 problem: ParallelTable with SQLExecute

I have run into the following problem: when I try to run the following code in Mathematica 9 I get SQL connection error on all kernels. The code is: ...
0
votes
1answer
239 views

Why does my attempt at parallelization not work?

I want to run some function with different parameters, parallel on 4 cores (i5). When I run it without using Parallelize, processor has ~25% utilization. It's a ...
10
votes
1answer
387 views

Parallelization and Hadoop

The short question: Has anyone used Mathematica in conjunction with Hadoop and does Mathematica's built in parallelization play well with Hadoop? The long version: So I have a Mathematica program ...
3
votes
2answers
558 views

why I can't define a commutator operator in this way?

I am trying to define some operators I used frequently.For example, I defined a KroneckerProduct operator as $ \otimes $ as follows: a_$ \otimes $b_:=a.b-b.a and this works fine. Then I want to ...
3
votes
1answer
210 views

Determining the partitioning of Do loop iterations between kernels?

Say I have some Do loop that I'd like to evaluate in parallel: Do[Something, {i, 1, M}]. I'd like to split this list up into ...
1
vote
1answer
132 views

Understanding a slowdown associated with wrapping a set of nested Do loops with a ParallelDo expression

I have a set of set of nested Do loops that require data from three different arrays (though the position from each array is fixed per cycle of the outer Do loop). Let's call these arrays: ListA, ...
2
votes
1answer
98 views

Parallel computing NInverseFourierTransForm

I am running the code below, and it works perfectly. I have some function in Fourier space, and I take the numerical InverseFourierTransform. However, I will have ...
6
votes
1answer
93 views

Is it safe to use older version subkernels with a newer version main kernel?

At the moment we only have access to version 8 of the Lightweight Grid (i.e. version 8 of the Mathematica kernel). Is it safe to run version 8 subkernels together with a version 9 main kernel? It ...
3
votes
1answer
67 views

local logfiles for remote kernels

I'd like remote slave kernels to produce log files on my local machine, subject to the following constraints: 1) I don't want to install a distributed filesystem or do other administrative work on ...
2
votes
1answer
83 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
296 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
501 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
333 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
227 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
100 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
222 views

How to make this code threadsafe?

I have the following code, schematically: ...
2
votes
1answer
267 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
312 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
401 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
170 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
250 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
193 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
287 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
295 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 ...
3
votes
1answer
237 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
220 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
198 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
396 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
211 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
267 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
160 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 ...