Questions tagged [parallelization]

Questions on parallel computing in Mathematica.

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2
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0answers
72 views

How to sync parallel kernels across multiple nodes on an HPC

I'm hoping to parallelise my Mathematica script across multiple nodes on an HPC, but I can't get it to work. My code has the following schematic form: ...
2
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1answer
71 views

Why `ParallelTable` doesn't work in this simple code?

The code Table[{a[i] = i^2, b[i] = a[i] + 100}, {i, 1, 4}] a[1] a[2] a[3] a[4] b[1] b[2] b[3] b[4] returns (correctly) the following output: ...
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122 views

gridMathematica: manual launching kernel on cluster node error

I have a cluster with gridMathematica installed, and the version is: Mathematica 7.0 for Linux x86 (64-bit) Command ...
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0answers
44 views

Trouble parallellising on HPC

I'm trying to carry out a parallel computation using Mathematica's inbuilt parallel functions, ParallelTable, etc. The problem is that the HPC doesn't seem to like ...
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1answer
55 views

Can operations with the CDF of random variables be parallelized?

I am trying to parallelize the computation of the CDF of a random variable (more precisely, a doubly noncentral $F$ variable) for a matrix of values. This is a MWE: ...
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118 views

Parallel computation on an HPC

This is my first time using an HPC and I am completely lost as to how to successfully launch a master kernel and a set of slave kernels. So far I have a .sh called <...
9
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3answers
3k views

Which processor and graphics card to use for my Mathematica license

Does my Mathematica license support processors with 8 cores? I have to choose between one of the following processors: Intel® Xeon® E5-1630 v4 Prozessor (4 cores, 3,7 GHz, 4,0 GHz Turbo) Intel® ...
1
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1answer
140 views

ParallelTable fail to distribute computation to local kernels and remote kernels

Recently I'm trying to process some experiment data, my PC with OS Win10 (mathematica v10.4) is not enough, so I connect to another PC with OS Ubuntu 16.04 (mathematica 11.0) by the way supported here....
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0answers
152 views

Parallelization of Monte Carlo numerical integration

I'm trying to parallelize some integral. What I do: I define integrand: ...
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0answers
251 views

Parallelizing NDSolve

I have a system of 300 coupled linear ODE's, which takes days to solve with NDSolve (i.e. but it's basically not possible to solve it since it requires >100 gigabytes of RAM). In other posts, I read ...
1
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1answer
256 views

ParallelDo works sometimes only

The following ParallelDo works sometimes (If I restart Mathematica, sometimes works). But, it usually does not work. Had not it worked all the time, I can be sure there is a coding error, but as it ...
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1answer
114 views

Speed up for NDSolveValue containing a coefficient of interpolate function

Could you give me some advice to speed up this code? I think especially NDSolveValue takes a lot of time. For j=1, it the NDSolveValue seems to be fast. But for j=2, I use the result of previous ...
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0answers
161 views

Parallelizing / speeding up a replacement rule over large list

I have a list of differentiated expression of the form {f[0,0,0],(f^(a,b,c))[0,0,0],...} where I have left the function as a general ...
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0answers
79 views

Finding the best way to try `Parallelize` a code

Consider a code like ...
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0answers
176 views

Keep kernels alive in parallel evaluations of several scripts

I have written a parallel script file that after initializing the kernels it puts the result of some computation in a file. I provide some external parameters to the script. I would like to run the ...
3
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0answers
57 views

Circumvent DistributeDefinitions

I have a code in which I create a few very large matrices with which I need to do long calculations. I have parallelised my code and, in the end, the thing that slows me the most is the time it takes ...
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1answer
68 views

Optimising matrix calculation [closed]

I was calculating the elements of a matrix like this: ...
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1answer
78 views

Large sum of 6-rank tensors

I have a question regarding the use of ParallelSum. I would like to perform a sum of the form: ...
4
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2answers
278 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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0answers
76 views

The conditions used in Sum or ParallelSum: Calling a function/variable

For some reason, I encounter a problem when doing the Sum and ParallelSum (or doing the Do or ParallelDo, e.g. such as the issue here), I figured that the potential cause of the problem can be ...
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0answers
202 views

Possible to use all cores for FullSimplify-ing elements from a matrix or vector? [closed]

I understand that FullSimplify, in general, uses one core only. However, when you FullSimplify a matrix or vector, I'm guessing Mathematica simplifies each element independently of the rest, so... why ...
2
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1answer
247 views

Does nesting NIntegrate inside ParallelMap hinder NIntegrate's built-in parallel execution?

I have a function fun[a_,b_] and I want to NIntegrate that function with respect to a for ...
4
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1answer
162 views

Remote parallel processing

(The problem has been narrowed down, and solved to a more simple one described at the end of the post beside UPDATE 3) I'm doing some numerical work that takes quite a long time to run on my computer ...
1
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1answer
31 views

Parallelize evaluation of points, storing points + output in list

I have a function which takes real numbers as inputs: MyFunc:=[v1_,v2_,v3_,v4_] and outputs a single real number. Now I want to evaluate ...
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1answer
139 views

Debugging parallelized code

Is it possible to add a stack trace for this parallelized code to see where the problems stem from? ...
0
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1answer
56 views

Force parallelization on this cell

I have three large lists that need to have certain values removed from them. Each list is completely independent of each other, so three threads should be able to execute these in parallel. Here's a ...
1
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1answer
114 views

Parallelization STOPS using all CPU power

I'm still not sure how to reproduce this, but it is certainly NOT a code-issue. I just hope I'm missing something easy, or this is a known issue with a known workaround. I have a script that uses <...
4
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1answer
274 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 ...
7
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0answers
68 views

What's with the weird HoldRest Attribute of ParallelMap?

Bug introduced in 10.0 or earlier and persisting through 11.1 I have noticed some odd behavior of ParallelMap: When the list, that is mapped over, is not inserted ...
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0answers
67 views

Dealing with cache file locks when using EntityValue in ParallelMap

I'm trying to run the following (naturally, I have FAR more zip codes and a much longer list of properties, both truncated for speed of the example): ...
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0answers
46 views

Improve timing of URLExecute command?

I am using a ionosphere model that runs online, IRI2016. The URL gives me a table with usefull parameters like electron density in upper atmosphere. The URLExecute...
5
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0answers
455 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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1answer
218 views

Part::wrsym Symbol Protected Error with ParallelMap

Here's my minimal example: ...
2
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1answer
102 views

How to optimizing Do and Manipulate for image processing purposes (Gravitational Lensing)?

I am trying to replicate LensToy using Mathematica, which is a web-based gravitational lensing simulator. I am having issues with Manipulate/...
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0answers
64 views

Using NearestFunction in ParallelMap: why the slowdown?

Intro I am trying to do various calculations (call some Analyze[point, neighbourhood] function) over the large datasets of points in 2D space. The nature of the calculations is irrelevant, but basic ...
10
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1answer
842 views

Parallelization with two Processors: only half number of cores run

I have a code which works really good in a parallelized way (with ParallelTable). I have a machine with 1 processor, 4 physical/8 logical cores, there 100% of the ...
5
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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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0answers
80 views

Parallel Evaluation

I want to speed-up the following program for obtaining Poincare Sections ...
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0answers
66 views

ParallelSum faster… if I don't load my own Package

I have a big sum to compute. I remarked that if I load my package, the parallelisation is as slow as the "non" parallelisation. Whereas, when I don't load it, the parallelisation is faster. The ...
38
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3answers
1k views

Good references for parallel programming in Mathematica

There are plenty of good references for all sorts of Mathematica programming: This forum is a great example for specific questions/"getting things done". Books like those by R.Maeder (esp. the now ...
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0answers
109 views

Updating “Parallel Kernel Status” window during evaluation

I really like the "Parallel Kernel Status" window for monitoring my parallel kernels. However, as long as a cell is evaluating, it is almost not updated (only the red and green circles that show ...
3
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1answer
72 views

Is it possible to recover remote subkernels if Internet connection is lost?

I was wondering if it is somehow possible to start a parallel calculation (where each part that is run in parallel takes about an hour) on remote subkernels, then disconnect the Internet connection, ...
2
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0answers
172 views

Why is my parallel version of `DensityPlot` slow?

I am exploiting the possibility to parallelize DensityPlot. This is my naive implementation ...
0
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1answer
120 views

Running out of memory when dealing with 210 million matrix elements

I have a program for counting pixel elements in RGB with a precision of two decimal places. Each image consists of 280 x 250 pixels, and the images are stored in a folder containing 1200 images. At ...
6
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2answers
243 views

How can I terminate a MathKernel that is running an external program after a timeout?

I'm using ParrallelDo to parallel run another program (windows executable) in 8 subkernels. Sometimes a SubKernel freezes. What I see in the task-manager is that ...
2
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1answer
178 views

Inconsistent behaviour of shared variable

It is well known that assignments to a variable shared between the main kernel and the subkernels are only executed by the main kernel. I suppose that when a subkernel has to assign to a shared ...
0
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0answers
51 views

Error message when calling Parallelize

I have some initialization code that I would like to run on any newly started kernel, and, following this question, my code starts with a call to Parallelize; on ...
11
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2answers
583 views

ParallelMap vs Map performance comparsion

The ParallelMap claims doing map faster than the normal Map, and I checked the demo does as the document describing but, I try ...
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0answers
365 views

How to use more CPU cores on linux? [closed]

I noticed that ParallelTable of Mathematica doesn't work well on my linux computer. WolframKernel uses just one cpu core. then I find That's weird.. I want to ...
3
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0answers
61 views

ParallelDo with NotebookDirectory[]

I have a main directory with subdirectories numbered (1, 2, 3, ...). In each folder there is an exe file. I execute this code: ...

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