Questions tagged [parallelization]
Questions on parallel computing in Mathematica.
750
questions
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ParallelTable - performance problem
I noticed some issue while making parallel computations with Table loop.
I noticed that when one of kernels finishes its part of job, it stops working and only rest of kernels work. But when ...
3
votes
4answers
305 views
Solving an equation in natural numbers
I am trying to solve the following equation in the Natural Numbers, with the condition $a\ge1$, $b\ge1$, and $r\ge3$:
$$\frac{a(a + 3)(a(r - 5) + (12 - r))}{9}=\frac{b (9 + b (-14 + r) - r)}{3}\tag1$$
...
4
votes
2answers
141 views
Finding the number of even numbers in Pascal's triangle (code gives memory error)
I have the following code:
...
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0answers
48 views
Running NonlinearModelFit in more one kernel simultaneously
I want to perform a nonlinear least square fit of data points upto 3000. Because the model I provide is huge polynomials with 300 to 400 fitting parameters to be estimated, my mac i7 computer proceeds ...
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vote
0answers
35 views
What does it mean when $MaxLicenseProcesses returns Infinity?
I am learning how to use Mathematica on a cluster, and a lot of this stuff is still way over my head. Please let me know if I am missing any crucial details.
The cluster uses Linux and uses Lmod to ...
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0answers
28 views
Parallel computation in a computer with 2 CPUs
My computer has 2 CPUs, each with 8 cores. However, when using parallel operation, only 8 cores of one CPU can be called. How can I set it so that 8 cores of the other CPU can also participate in the ...
2
votes
1answer
66 views
Implementation of Dirichlet-Neumann method
I am new in Mathematica and I was trying to find documentation on the Dirichlet-Neumann and Neumann-Neumann methods (which are part of Domain Decomposition Method), but I couldn't find any. Can ...
2
votes
0answers
31 views
Mathematica parallelization error
I am trying to parallelize some code in Mathematica 11.3 under Ubuntu 20.04, but I get the following errors:
the code is a s follows:
...
0
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1answer
102 views
Writing a program that finds for what $(x,y)$ a function gives a perfect square number
The overal question I am trying to answer is:
For what $(x,y)$, which are positive integers, is the following number a perfect square number?
$$9 \left(x^3 (y-2)^2+3 x^2 (y-2)-2 x (y-45) (y-2)+7 (y-1)^...
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0answers
28 views
How can I parallaize expresion that contains ParallelSum?
I have this code where the last part contains ParallelSum
...
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0answers
52 views
Generating and operating with random number
I'm working basically with the creation of random numbers that represent the positions of $N$ electrons within a box. Later, I sum all the individual electric fields generated by the electrons, thus ...
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vote
2answers
132 views
Fast way to check if $f(x)>x$ for what value of $x$
In order to find the value $x$ for which $f(x)>x$, I tried it using the following code:
ParallelTable[If[TrueQ[f[x]>x],x,Nothing],{x,0,10^9}]
For some ...
0
votes
1answer
49 views
What is the cheapest method to get cloud computing, remote kernels, HPC access, connection to clusters or GPUs?
I want to be able to run parallelisable tasks quicker and on better hardware. Are there any services that can easily do this with my personal copy of Mathematica?
2
votes
0answers
121 views
How can I numerically evaluate the trace of a large matrix to speed up the code?
I have a large matrix (4Wn*4Wn) resulted from multiplication of different matrices and I would like to evaluate the trace numerically to speed up the process. Here ...
5
votes
2answers
214 views
How are the CPU cores distributed to each kernel in parallelization calculation?
Just want to make sure that I understand correctly before I ask questions. I saw some people saying that some functions in Mathematica will automatically use multi-cores (I am not referring to those ...
0
votes
1answer
109 views
How can we speed up a matrix multiplication using ParallelTable and ParallelISum?
I do belive that Mathematica can work as fast as other packages, but it is really sensitive to the way we write the code. Here I would like to evaluate a trace resulted from a matrix multiplication at ...
0
votes
1answer
42 views
How can I use ParallelTable with ParallelSum effectively?
I have this expression (as an example) as a function of nc and nr (real one is more nasty)
...
3
votes
1answer
112 views
“Part specification is longer than depth of object.” only when executing inside ParallelTable (but not Table)
Background
I have a function I would like to execute inside a ParallelTable. One of the arguments of this function is another function. So it looks something like this:
...
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0answers
48 views
Is possible to make RowReduce more efficient?
I have huge matrices (not square ones, the rows are many more than columns), like 85k rows and 50k columns. I would like to use RowReduce on these, but it takes too much time to do that. I need to ...
3
votes
1answer
146 views
How to make a progress indicator work in ParallelTable mode in Mathematica?
I developed a code to display a progress bar, percentage and time dynamically when I am running a plot that calculates things (using user defined function called computethings). It works nicely in ...
4
votes
2answers
118 views
4X4 matrix of distinct cubed integers with identical row and column sums
I wrote the following code:
...
0
votes
0answers
34 views
Parallelized FactorInteger
FactorInteger has no documented option to be parallelized. Can this be done by some clever hack? Or is there a ready-made substitute that makes use of multiple ...
4
votes
1answer
135 views
Why Does Parallelization Not Speed Up these Seemingly Well-Parallelizable, Simple Functions?
Original Example
Consider function f, a parallelized version fPar, and a coarsest-grained parallelized version ...
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0answers
39 views
Parallel Matrix Manipulation: find eigenvalues and construct list
I'm having some trouble with the Parallel commands in Mathematica 12.1:
I need to construct a table where its entries are {M, Eigenvalues of X[M]}, where X is a square matrix of dimension N with N big ...
5
votes
1answer
71 views
Prevent resurrection of dead subkernels
How do I prevent Mathematica from trying to resurrect subkernels that it has deemed to be dead? I would like to avoid this:
...
6
votes
2answers
100 views
Choose the number of kernels used by ParallelTable
By default, on my system, ParallelTable uses 4 kernels. Is it possible to change the number of kernels used, for example using only 3 instead of 4?
7
votes
1answer
89 views
Is there something wrong with DistributeDefinitions?
I have the following code, which fails to distribute the DownValues for the symbol f. Could anybody please explain what is wrong.
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0answers
35 views
Difference in computation speed of Eigensystem not to expectation for ParallelTable and Table
I was trying to compute the time it takes for Eigensystem to evaluate while being inside a ParallelTable, as it is well-known LAPACK subroutine has an inbuilt Parallelization to it. And the difference ...
0
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1answer
36 views
Evaluating values from a indexed ParametricNDSolve solution in parallel
I have a ParametricNDsolve solution for a differential equation for a huge system given by s1. I have no problem in evaluating ...
2
votes
1answer
39 views
DecompositionNDSolveValue analogue for NDEigenvalues
In FEMAddOns there is a function DecompositionNDSolveValue to solve stationary PDEs on a cluster. Is there a similar way to solve the eigenvalue problem for a system of ODEs in parallel kernels, ...
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0answers
123 views
Simplify Vs FullSimplify
I performed an integral and received an extremely long answer. I tried running FullSimplify on the answer, and after 72 hours gave up. Does ...
3
votes
1answer
61 views
Tracking progress of ParallelTable Computations
I have a notebook where I work with large datasets, where the data is stored as an A x B array of signals, where each signal is often 1000 samples long. In the past I would track the progress of ...
1
vote
2answers
70 views
How to Parallel submit nested do loop
This is the first time I'm trying to parallel compute something on Mathematica. So this question might be silly.
I have a nested Do loop of the form:
...
8
votes
1answer
505 views
Parallel computing: cores vs threads
I'm running Mathematica on a machine wtih 48 cores and 96 threads. I want to limit the number of threads the computation can have access to. If I give LaunchKernels[1] it correctly launches a single ...
2
votes
1answer
37 views
Filtering solutions using the Select function [closed]
I have a certain code that output in the following format:
{{a1,b1},{a2,b2},{a3,b3},...,{an,bn}}
Where $a_1$ and $b_1$ etc are numbers. Now I want to filter ...
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0answers
32 views
Parallelization option gives Import error for Package files
I have an issue when trying to use parallelization when loading a stand-alone Package. To simplify the question I have a few scenarios:
The first scenario, with single-kernel evaluation, works fine:
...
3
votes
0answers
59 views
Parallelize import of many files
I'm trying to speed up the import of a large number of files, using ParallelTable to store them in a indexed variable, eqDump. The files are in the folder "Frames" and are named "Conf_Run.1000", "...
2
votes
0answers
76 views
Aborting any computation that takes too long
One of the biggest annoyances in Mathematica is that it will often hang up without any way to abort (i.e. Alt + . or other methods can't stop the computation). Is ...
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vote
0answers
30 views
How to close a specific Kernel after completion of evaluation in ParallelDo
I have a particular code that I have to run over several different parameters. I am using ParallelDo to parallelize the process. Due to the nature of the evaluations some Kernels finish the ...
0
votes
1answer
22 views
Defining specific evaluation task to specific parallel kernel
Is it possible to specify particular task to a particular kernel to be evaluated in parallel?
0
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0answers
36 views
Why ParallelTable warns where Table runs quietly?
I have a code involving ParametricNDSolveValue and FindRoot to find a trajectory [actually, trajectory of a line that everywhere ...
1
vote
1answer
32 views
A problem with nested tables and parallelization
My code contains the structure
Table[....,Table[....,{m1,1,N}],{m2,1,M}]
and I would like to use ParallelTable to improve timing. Empirically, I know that ...
7
votes
2answers
143 views
Parallelize GroupBy
I have a huge list longList that I want to split into two parts depending on whether an element of the list satisfies the condition: ...
1
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0answers
21 views
Command line instances sharing variables [closed]
I have a Mathematica notebook that I have been running on my desktop and am working on moving it over to a high-performance cluster.
One part of the code is a random walk algorithm that uses a ...
1
vote
0answers
31 views
ParalleTable can't use 100% CPU
I have two notebook. A.nb and B.nb. When I run the ParalleTable in A.nb, it will use 100% CPU. But I change some items in A.nb to get B.nb. When I run B.nb, it only used 50% CPU.
I can't find the ...
2
votes
0answers
45 views
How can I parallelize this calculation?
I need to compute a sum function:
$$E=\frac{(2 \gamma )}{\delta ^2} \sum _{m,n,p,q=0}^{\text{mMax}-1} a_m a_n a_p a_q \text{A}(m) \text{A}(n) \text{A}(p) \text{A}(q) \text{D}\left(\frac{1}{2} (m+n+p+q)...
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vote
0answers
64 views
7X7 matrix of distinct cubed integers with identical row and column sums
Problem: find a 7X7 matrix of distinct cubed integers with identical row and column sums.
Well, I have the following code (that came from @kglr from my previous question):
...
0
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0answers
30 views
Closing sleeping kernels in parallel computation
I want to close the kernels which have completed their jobs in parallel computation. I have a test code as following:
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2
votes
1answer
48 views
ParallelTable does not evaluate DLL functions
I have a function programed in C which I load in MMA with
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0
votes
2answers
91 views
Solving a system of equations using the data generated by PowersRepresentations and ParallelTable
First of all, it is possible to check the code that I am asking for because I know that $x=3051$ must yield at least a solution to the problem.
Well, I have the following system of equations:
Now, I ...
