Questions on parallel computing in Mathematica.

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4
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1answer
58 views

How can I access memoized values from parallel evaluation? [duplicate]

I want to evaluate a table of functions with ParallelTable. Here is the serial code: ...
4
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0answers
84 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 ...
4
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0answers
92 views

Improving the speed of an optimization algorithm via compilation and parallellization

I have written an implementation of eight variants of the PSO-algorithm and I want to test them over a set of test functions. I am using parallelization as it improves the speed a lot and I have also, ...
4
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0answers
366 views

ParallelTable kernels die - maybe Mathlink timeout?

I am new to parallel computing in Mathematica. I am using LaunchKernels[16] ParallelTable[] to parallelize calculations. The ParallelTable consists of approx ...
4
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0answers
354 views

OpenCL vs. CUDA with Mathematica

I am thinking about using GPU programming with Mathematica using a MacBook Pro with a NVIDIA GPU. At this page, the Mathematica documentation says "Programming OpenCL in the Wolfram Language is simple ...
4
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0answers
354 views

Death of parallel sub-kernels

EDIT : Finally, the new Mathematica 10.0 seems to fix it. I have a little parallelization problem. I wrote a code to generate a quasicrystal by dynamical generation. Here the code: ...
4
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0answers
300 views

How to force the compilation language to be C++ (not C) in CreateExecutable or CreateLibrary

I'm trying to speed up a section of a Mathematica 9.0.1 notebook by performing some calculations in C++ with the Cilk Plus and Threading Building Blocks tools available for the Intel C++ 14.0 compiler ...
4
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0answers
120 views

LibraryLink parallel performance

I'm trying to use a LibraryLink function in parallel. It is an embarrassingly parallel problem, so that no dependency between those parallel tasks. However I can only get the parallel efficiency about ...
4
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0answers
424 views

To what extent can NonlinearModelFit be sped up? [closed]

Can NonlinearModelFit be parallelized or compiled to allow one to achieve a scalable speedup for a fitting procedure? Attempting to use this function to fit a ...
4
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0answers
135 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. ...
4
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0answers
250 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 ...
4
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0answers
87 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 ...
3
votes
3answers
177 views

Optimizing a series of basic matrix operations—scaling doesn't seem right with matrix size

I have a simple operation that I'd like to apply to an n×n matrix. My problem (well, one of them...) is that it runs in, say, 4 seconds for a 100×100 matrix, but it took five and a half minutes to run ...
3
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3answers
654 views

How can I suppress Print in parallel evaluation?

When using a function that includes Print statements, one can suppress the output by ...
3
votes
1answer
702 views

Suppress warnings in ParallelTable

I'm using ParallelTable to evaluate a function that involves NIntegrate. There are a lot of ...
3
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1answer
145 views

How to speed up filling a matrix as much as possible in a loop?

In order to find the solution of an $n\times n$ system of nonlinear equations by the method $x_{k+1}=x_k-D_k^{-1}f(x_k)$ where $D_k$ is an approximation of the Jacobian and defined by \begin{equation}...
3
votes
1answer
197 views

How can I understand this short example?

First launch kernels LaunchKernels[4] {KernelObject[5, "local"], KernelObject[6, "local"], KernelObject[7, "local"], KernelObject[8, "local"]} Then I calculate ...
3
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1answer
731 views

Parallel computation of a system of differential equation

I need to solve a system of differential equations which contains, at minimum, ten thousands of differential equations. Actually, I am trying to solve density matrix equation $$\frac{d}{d t}\rho(t) = ...
3
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1answer
433 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
194 views

Alternatives to For/Do Loop to optimize indexing Matrix

I am trying to optimize my code that searches for elements in the rows of matrix that are greater than 0. Then use that position to grab the element from other matrix. I use the do loop to iterate ...
3
votes
1answer
107 views

Fast evaluation of a function in many points

I need to feed to an external program a number of points (in Complex128 format) generated from the numerical evaluation of some function, e.g. $e^{i \vec{k}\cdot\...
3
votes
1answer
156 views

Problem with ParallelTable

The following code creates an array of length N, such that the sum of elements is less than or equal to p and each element is between 0 and l. All elements are integers. (code courtesy, Kellen Myers ...
3
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1answer
243 views

Bug in parallel computing

The following is a simplified example. We construct a library function f and another library function g, in which the library function f is called. ...
3
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1answer
207 views

Optimization of power tower fractal generator [closed]

I tried to optimize the code for generating power tower fractals from here. As the author suggested, I tried to memorize the points already tested in a list. Here is my code : ...
3
votes
1answer
340 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 ...
3
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1answer
62 views

Side effects with ParallelDo

Hi guys I've the following problem with ParallelDo: if I run the code: ...
3
votes
1answer
67 views

What does it mean when number of LaunchKernels much greater than cpu cores?

My Laptop only has two cores, In[69]:= $ProcessorCount Out[69]= 2 And ...
3
votes
2answers
167 views

Efficient and fastest way to execute 4 nested loops

I have a question regarding the use of ParallelDo. I tried to parallelize the following code involving four nested Do loops by ...
3
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1answer
117 views

Mathematica 10, With and ParallelEvaluate: New syntax?

Consider the following trivial code to evaluate something on a parallel kernel ...
3
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1answer
91 views

Why doesn't my expression evaluate at the subkernel?

Consider this code: ...
3
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2answers
145 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
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1answer
84 views
3
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2answers
206 views

Definitions inside ParallelTable?

How can I make definitions inside ParallelTable to use them outside? For example, if I execute: ...
3
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1answer
480 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 ...
3
votes
1answer
83 views

How to simultaneously monitoring parallel computations in different Kernels?

I have a question about monitoring parallel processes. Let's suppose that I am running the following code with 5 active Kernels. ...
3
votes
1answer
62 views

Shared variable can not be distributed again after UnsetShared

I see a weired behavior in my MM 10.3 version. Can someone reproduce it or explain what is going on? The code is easy: ...
3
votes
1answer
127 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
322 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
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1answer
112 views

Creating a parallelizable DiscretePlot

To my knowledge, DiscretePlot cannot be parallelized, although one can simulate the default behavior of DiscretePlot and get the ...
3
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1answer
34 views

Skipping commented in a stream from OpenRead

Is there a solution to skip comments in text files that are imported with OpenRead? I know there are solutions for Importand <...
3
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1answer
187 views

Image background subtraction using parallel computing

I am developing a program for pattern recognition. I want to use the parallel computing to get a real time application. I have two cameras where each one gives n frames/second. I need to process the ...
3
votes
1answer
367 views

Parallel kernel and front end

I have a piece of code which looks like this: ParallelTable[ Monitor[ Table[ <code here> ,{i,i1,i2]; ,i]; ] so basically a ...
3
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1answer
107 views

ParallelTable Works in Regular Notebook but Gives Error When Packaged

Consider the following: ...
3
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1answer
659 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
1answer
59 views

Execute a function in parallel on different cores?

Suppose I have a function f which takes a list and does something with it: ...
3
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1answer
61 views

LaunchKernels behavior

I have one processor with 2 cores on my local computer. CloseKernels[];LaunchKernels[] (* {"KernelObject"[1, "local"], "KernelObject"[2, "local"]} *) I can't ...
3
votes
2answers
106 views

Add Results of ParallelMap in Parallel

I'm new to coding in parallel, but I really could use it. I need a command to call a function on each element in a huge list, and then add them all up. Currently I use something like this: ...
3
votes
1answer
301 views

Setting up parallel remote kernels

I'm having trouble setting-up a parallel remote kernel. I have correctly set-up remote kernels and can use them instead of the local kernels, by executing tunnel.sh ...
3
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1answer
153 views

Parallel Apply on a deeply nested expression

I have a deeply nested expression, i.e. something like {{{{...}..}..}..}, and I'd like to use Apply in a parallel fashion, e.g. <...
3
votes
1answer
117 views

Dynamic Output during ParallelMap

I can't seem to figure out how to dynamically output a variable that is being used in a parallel evaluation. Below is an example function that demonstrates my problem. ...