Questions on parallel computing in Mathematica.

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3
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0answers
224 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: ...
3
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0answers
94 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 ...
3
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0answers
181 views

Launching Remote Kernels takes a lot of time

I recently played around with establishing a remote kernel setup without using mathematica grid. To do this I use the LaunchKernels[] command and ...
3
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0answers
317 views

To what extent can NonlinearModelFit be sped up?

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 ...
3
votes
0answers
189 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 ...
2
votes
1answer
660 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 ...
2
votes
2answers
629 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 ...
2
votes
1answer
240 views

Parallelization of REvaluate[]?

Is there a way to run several RLink computations via REvaluate[] in parallel, e.g. with ParallelTable[]?
2
votes
2answers
299 views

Will Parallelize in this programme help it run faster? [closed]

I have a programme, and inside it this line of code. ...
2
votes
1answer
430 views

Suppress warnings in ParallelTable

I'm using ParallelTable to evaluate a function that involves NIntegrate. There are a lot of ...
2
votes
2answers
55 views

Disappearing variable in parallel computations

I have a problem with parallel computations. When I try to evaluate formula like this: Do[m[i]=2,{i,1,10}] and then I try to call for instance ...
2
votes
2answers
317 views

Is there a way to parallelize the convolution component of EdgeDetect?

Provided an image like - test = Import["http://upload.wikimedia.org/wikipedia/commons/d/d5/Sunflowers.jpg"] We can run ...
2
votes
1answer
257 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
94 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 ...
2
votes
2answers
81 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, ...
2
votes
1answer
112 views

ParallelEvaluate: Evaluation Rules and Increment

I'm trying to understand how ParallelEvaluate works, considering the two following snippets: ...
2
votes
1answer
181 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
99 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 ...
2
votes
1answer
382 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 ...
2
votes
1answer
278 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
1answer
44 views

Parallel kernels cannot launch: LinkOpen::linke error [closed]

I have been regularly using parallel kernels on my machine but this morning all I receive is a cryptic error whenever I call any parallel function (LinkOpen::linke). As far as I can see sequential ...
2
votes
1answer
80 views
2
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1answer
125 views

ParallelTable slowdown for a task involving ComponentMeasurements

I'm having trouble understanding a slowdown associated with code I'm running, which should be trivial to parallelize. My code looks something like this: ...
2
votes
1answer
59 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. ...
2
votes
1answer
65 views

Button action preventing parallel execution?

I couldn't find a better title, so I'll jump straight to the example! There is this long list of slow jobs to be executed in a parallel way, at the press of a button: ...
2
votes
1answer
130 views

Launching external program in background process with ParallelSubmit

I work on the implementation of an image processing pipeline in Mathematica in which I also would like to use external programs to do certain processing steps. As an example I have macros for the ...
2
votes
2answers
182 views

Definitions inside ParallelTable?

How can I make definitions inside ParallelTable to use them outside? For example, if I execute: ...
2
votes
2answers
191 views

Executing several input cell simultaneously with parallelization

How can I execute more than one input cell simultaneously using different processor. For example consider this two cells ...
2
votes
1answer
274 views

How to parallel this nested table efficiently?

I have an 8 core CPU and want to parallel evaluate the following nested Table Table[Table[expr[i,j], {i,1,10}], {j,1,4}] But ...
2
votes
1answer
259 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. ...
2
votes
1answer
118 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 ...
2
votes
1answer
77 views

ParallelMap doesn't work with an Association. Is this a bug?

I receive a ParallelCombine::nopar1 error when executing ParallelMap[Identity, <|1 -> 1, 2 -> 2|>] Is this an ...
2
votes
1answer
93 views

How to access directly the “CUDA Memory” address from another parallel kernel?

I work with CUDALink and have some small successes. I use direct calculation on GPU without using CPU (only for sanding commands for CUDA function). Until now I have stored on the hard drive with ...
2
votes
1answer
85 views

Intensive test parallel computation?

I need an example of a not-too-complicated yet intensive parallel computation in Mathematica. The result of the computation should be known before hand. I need this to test the capabilities of a ...
2
votes
1answer
137 views

How to parallelize the most outer loop only?

I have two Doloops. The outer loop iterate over the inner loop. The inner loop contains a set of step by step instructions which each next step depends on the ...
2
votes
1answer
58 views

Lightweight Grid saving to file

I'm trying to launching my first jobs on LightWeight Grid using ParallelDo. I have 10000 jobs, each of which returns a 1M output, which I would like saved to a file on the head machine, one file per ...
2
votes
1answer
343 views

Remote Kernel Setup: SSH fails with exit code 32512

I am having trouble with configuring parallel kernels. What I want to do is the following: run remote kernels on my home server to which I would like to connect from work using my laptop. Both ...
2
votes
1answer
66 views

Parallelization and evaluation of random number generation

Suppose I have the following functions: ...
2
votes
1answer
160 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
1answer
191 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 ...
2
votes
1answer
250 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 ...
2
votes
0answers
50 views

Parallel evaluation of symbolic matrix eigenvalues

I'm trying to find eigenvalues of symbolic hermitian 40x40 block matrix. It is made from 20 2x2 matrices like this: ArrayFlatten[Table[M[m,n],{m,1,20},{n,1,20}]] ...
2
votes
0answers
55 views

Is it possible to automatically apply Parallelize when possible

Parallelize in Mathematica is pretty easy to use. Most of the time, applying Parallelize to an expression, it tries to evaluates ...
2
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0answers
46 views

Export on local machine results of a parallel computation using remote kernels

I've got a long calculus to do with Mathematica. I've Parallelized the code using local kernels and remote kernels. I'm using a ParallelDo loop with an ...
2
votes
0answers
30 views

ParallelSubmit and WaitNext: check if a job is done before calling WaitNext

Say I process something with ParallelSubmit: LaunchKernels[] job = ParallelSubmit[1 + 2] Parallel`Developer`QueueRun[] Then, I will use ...
2
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0answers
67 views

What was the thought behind the parallel versions of Table, Map, etc..?

There separately named versions of the parallel analogues of Map[] and friends: ...
2
votes
0answers
109 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. ...
2
votes
0answers
95 views

Parallel Kernel Status

For parallel computing, the window Parallel Kernel Status shows some information on the subkernels. I can use two kernels, and which each of them I can do parallel computations. However, it seems that ...
2
votes
0answers
128 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 ...
2
votes
0answers
36 views

do successive parallel computations require distribute definitions at each intermediate step?

Suppose I am doing a parallel computation, say, using parallel table. I distribute necessary definitions to all kernels. After computation is done, I would like to use the first result in another ...