Questions tagged [parallelization]

Questions on parallel computing in Mathematica.

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5
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1answer
316 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. ...
5
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1answer
969 views

How does Mathematica detect the number of cores in a system?

I'm running Mathematica 10.3.1.0 on a machine with 16 cores, but Mathematica (in the Parallel settings) says "Number of processor cores is 8." It's a 16-core Opteron 6300 chip on an Ubuntu system. All ...
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1answer
178 views

Eigensystem on HPC

I am submitting Mathematica jobs to an HPC. I have a large matrix that is a function of (x,y) and I am diagonalizing it for around 500 points in the plane. My initial idea was to request a node with ...
5
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1answer
214 views

Print messages of parallel kernels to console

This question shows how to print output to the console, but how about messages? For the main kernel, I know this way: ...
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1answer
140 views

Problems with ParallelDo

As example I have the following two image sets (10 images each, png format, 8 bit gray scale) in two different directories and want to determine the mean intensity of each image: set 1: https://drive....
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2answers
321 views

ParallelTable vs. Table: Parallel gives NMinimize:nnum error

I have run into an issue where I am getting nnum errors when I use ParallelTable, which I do not get when I use Table (and even ...
5
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2answers
299 views

Creating a version of ParallelTable that parallelizes over all levels

Mathematica's ParallelTable (or any Parallel function based on iterators, like ParallelDo) only parallize the computation for the top level iterator (even with `Method -> "FinestGrained"' set). For ...
5
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1answer
534 views

How to Export from ParallelDo? [duplicate]

I'm running a simulation with parallel, and I want the results from each parameter set exported to a file whenever it's done (because the parameter space is huge and my computer doesn't have enough ...
5
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1answer
791 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 ...
5
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1answer
331 views

clear variables on parallel kernel

Short question: what is the proper way to clear a variable on a given kernel ? AND how can I ensure that the memory will indeed be freed subsequently ? Full question. Let me elaborate this question ...
5
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1answer
351 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. ...
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1answer
1k views

Parallel evaluation and memory use

I have never used Mathematica's parallel evaluation before and have some trouble getting it to work properly. For the record, I am running Mathematica 9 on Linux with an Intel Core i7 processor (4 ...
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1answer
403 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 ...
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126 views

Optimize Use of PeakDetect in Mathematica

I am quite new to Mathematica and I am looking for some advice in order to improve and optimize my code. Here is what I am trying to do: Open a stream Read the stream line by line and store it in "...
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87 views

Random number generation within Compile and Parallelization->True

According to this thread RandomChoice is a compilable function. I use it to generate random numbers in a compiled function with parallelization enabled. I wrote ...
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37 views

Efficient Parallelization of PermutationReplace

I am generating the orbit of a partition of a set of size $n$ under the action of the symmetric group $S_n$. PermutationReplace won't allow itself to be parallelized. Why is this ? Is it because the ...
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452 views

Can't Launch Kernels, Updating from Wolfram Research Server

So, I'm running Mathematica on an HPC cluster using the math module command line interface. I'm trying to figure out some problems with attempting to parallelize my ...
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0answers
45 views

Random Number Generation on Parallel Cores [duplicate]

So, I've noticed an odd trend in some of my Mathematica results recently- I'm running large Monte Carlo simulations on a system that involves running several jobs independently, each on a different ...
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114 views

Is there a clean way to parallelize multi-index tables?

The documentation of ParallelTable indicates that if you want to parallelize the evaluation of a table of more than one dimension, such as ...
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0answers
206 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 ...
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0answers
153 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, ...
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82 views

The change of precision doesn't work in ParallelDo. Is it a bug in Parallel?

Cross-post: http://zhidao.baidu.com/question/2075301703219376588.html Input: ...
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394 views

Mathematica + RasPi + Parallela = Kaboom?

Is it possible to use the Parallela computing platform to enhance Mathematica computing on a Raspberry Pi? It's not at all clear to me how to interface the two boards (here it says it's done via ...
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0answers
208 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 ...
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3answers
1k views

How can I suppress Print in parallel evaluation?

When using a function that includes Print statements, one can suppress the output by ...
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2answers
459 views

Why does ParallelDo return wrong number of results

I am testing out some optimization algorithms. I have written the code with a Do loop inside a Do loop. The inner loop is the algorithm itself and the order the steps are executed is very important. ...
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1answer
730 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 instead....
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2answers
252 views

Parallelize function evaluation with different parameters

How do you run the same function multiple times and at the same time, but with different parameters? I have had a look at ParallelEvaluate[] but it is meant to run ...
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2answers
619 views

How to use multicore in this case?

Say I have something like this: myfun[dataA,X1,Y1,Z1,W1]; myfun[dataB,X2,Y2,Z2]; myfun[dataC,X3,Y3,Z3]; (* with many more of the same *) Each would take about 5 ...
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1answer
151 views

Optimization: Differences between Map and ParallelMap

I just was studying Map and ParallelMap in a MacBook Air of 2 kernels. So, I tried comparing the AbosoluteTiming of these input lines and the outputs sorprised me because I thought a ParallelMap would ...
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2answers
92 views

Shadowing of symbols with ParallelEvaluate and packages

I'm new to Mathematica's parallel evaluation and can't really figure out how to properly use packages on parallel kernels: I get ::shdw messages complaining about ...
4
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2answers
319 views

Elegant way to partition list to be faster than `ParallelTable` (using `ParallelSubmit`), or some alternative?

Suppose you have a function fun[x_] := (Pause[.05*x]; x^2); of which you know that its evaluation time increases with its argument - in this case obviously ...
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1answer
244 views

How to further accelerate arithmetic with Fermat Pseudoprime and Fibonacci number

I've been working on this all night, and I have made this go pretty fast, compared to my first iteration of the program, but now I'm out of ideas. I'm trying to write a program to test (by good old ...
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2answers
272 views

ParallelSum vs. Sum: New functions also defined in other Kernels?

Set-Up: While I had tested a few toy examples that ParallelSum produces the result faster than the Sum, here I encounter one example in my code that the ParallelSum produces either wrong/incorrect ...
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1answer
780 views

Why can't Mathematica parallelize this?

The following code makes mathematica print "ParallelTable::nopar1: [...] cannot be parallelized; proceeding with sequential evaluation." ...
4
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1answer
510 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 ...
4
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1answer
191 views

Run multiple NDSolve Simultaneously

In a previous question I asked how to speed up the performance for NDSolve for a single evaluation. With the help provided, the solution is much faster. Now, I'd like to run the same code in different ...
4
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1answer
217 views

ParallelEvaluate: Evaluation Rules and Increment

I'm trying to understand how ParallelEvaluate works, considering the two following snippets: ...
4
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1answer
140 views

Right syntax to launch multiple kernels on SLURM cluster

I have access to a SLURM based cluster where I allocate 2 nodes, each with 12 processors. I am looking for a way to launch all 24 kernels to utilize the resources to the maximum for parallel ...
4
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1answer
759 views

Parallelization does not use all cores fully

On a new laptop with a 6-core i7-8850H in Mma11.3, I'd like to use its full capabilities. Unicore code ...
4
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2answers
697 views

Finite Element Parallel NDSolve

How can "MeshElementBlocks" be used with NDSolve to run a parallel kernel evaluation of a Finite Element problem? ...
4
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2answers
318 views

Mysterious behaviour of ParallelTable

This question is related to Export bug in combination with ParallelTable?. The following code shows an even stranger bug than in the upper question. The y-axis should always be logarithmic, but in ...
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2answers
439 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, ...
4
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2answers
335 views

Definitions inside ParallelTable?

How can I make definitions inside ParallelTable to use them outside? For example, if I execute: ...
4
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1answer
248 views

Parallelization of the stochastic Euler scheme

I wrote a simulation to approximate the law of a stochastic differential equation via a Monte Carlo method using the stochastic Euler scheme. Then I thought, it would be a good idea to speed up ...
4
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1answer
680 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
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1answer
238 views

NDSolve`Iterate with shared variables

I'm trying to parallelize a set of NDSolves that share a few variables. Here is a short working example: ...
4
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1answer
270 views

Monitor ParallelMap (again) - how to predict the number of function calls efficiently?

I am currently implementing a function to let me monitor the progress of a computation running in parallel (similar to the answers in Monitor doesn't work with ParallelTable). The goal is to have ...
4
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1answer
177 views

When using Java objects through JLink, how can I multitask the objects?

I use Mathematica 11.0.1 on Windows 10 and have a Java class which acts as a 'facade' for a headless browser (PhantomJS). In Mathematica I instantiate the class through JLink as follows: ...
4
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1answer
91 views

Programmatically access the data from the Parallel Kernel Status window

I want to show the parallel kernel status within a notebook, and not in the separate Parallel Kernel Status window. How can I programmatically access the Performance Measurements data shown in the ...

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