Questions on parallel computing in Mathematica.

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Placing package in existing Utilities` context has odd paraellelization effect

I noticed this in V.10 but possibly it was in effect in V.9. I have a package which in simplified form looks like:- ...
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74 views

Diagonalization in parallel

I would like to diagonalize one unitary non-sparse matrix of size 12870 with complex number entries (not symbols, this is really a numerical problem). Is is possible to make eigensystem run in ...
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82 views

Parallel numerically integrated function can't be plotted

I've been working on a problem where I need to integrate a function numerically. The function is quite complex and it takes almost an hour for Mathematica to make a plot. To speed the process up I ...
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514 views

Threads vs Cores: How many kernels need to launch in parallel Mathematica?

I have a dual-core intel machine. I would like to test how many parallel local kernels should be launch to get the optimized performance. Knowing that the HyperThreading technology of Intel could run ...
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40 views

Parallelizing an associative binary operation

I have an associative binary operation '.', which I often use in this sort of way: result = expr1 . expr2 . expr3 . expr4 The ...
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60 views

Why ParallelTable gives different answer than Table [duplicate]

Consider this code: ...
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188 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 ...
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141 views

Why doesn't ParallelMap improve the performance of FoldList?

This question arose during my analysis of the following problem: filling gaps. (The code used here is Simon Woods's work.) FoldList seems to not cooperate with ...
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171 views

Parallel linear algebra with arbitrary precision

Is it possible to do parallel linear algebra with arbitrary precision within Mathematica (in a simple manner, as is done for the machine precision)?
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197 views

Return Functions from parallel execution of module

I wrote a module which numerically solves an ODE using NDSolve. The result from this is e.g. either ...
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1answer
244 views

Why does my attempt at parallelization not work?

I want to run some function with different parameters, parallel on 4 cores (i5). When I run it without using Parallelize, processor has ~25% utilization. It's a ...
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3answers
350 views

Silence debug output from Parallelize?

I have this script, which does a bunch of image aligning in parallel: https://gist.github.com/8848a25a15da013ed1ad However, on EVERY print, Mathematica also prints from what Kernel the message came ...
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1answer
110 views

ParallelTable and DistributeDefinitions

I have a function in the following form: function[...] := With[ {...}, Table[ anotherfunction[i, j, ...], {i, ...}, {j, ...}, ... ] ] If ...
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2answers
752 views

nested numerical integration: not valid limits?

I encountered an error when I was hoping for some Mathematica (8.0.4) magic sparing me to code up numerical integration, function approximation and root-finding myself. The broader context and the ...
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1answer
79 views

ParallelTable not firing

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1answer
81 views

Can ParallelDo speed up a counting problem?

How to make parallelize the following code keeping the same "idea". The example I have in mind is more complicated, but I would like to know if a program of this structure can be parallelized? ...
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1answer
95 views

Parallelize matrix operations

I'm trying to reduce to a minimum the time of some matrix operations. When I don't parallelize and write the code in the most compact form I get the operation done in around 1sec (is this good? the ...
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1answer
180 views

Parallel computation of NDSolve and a problem

I used this code to solve a system of differential equations: ...
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1answer
138 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. It's like something ...
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1answer
430 views

ParallelTable 70 times slower on 16 cores than Table on single core

Consider these code(sorry it's messy), why the ParallelTable version is 70 times slower than the Table version? ...
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1answer
453 views

On the parallelization of matrix multiplications in Mathematica 8

I have installed Mathematica 8, but I think the commands for parallelizations do not work! Even when I try to test the example in the Help of Mathematica, I face with ParallelDo::nopar: No ...
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1answer
264 views

How to distribute definitions when loading external *.m packages

i'm struggling with the following. I use ParallelTable and it works transparently as it automatically distributes the needed definitions. However, I run into ...
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1answer
70 views

ParallelMap returns incorrect results over Map

I've written a function to pull in the useful column of a large data file: ...
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1answer
56 views

ParallelTable and plotting result of own define funtion

I define function which return a list of numbers ...
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2answers
69 views

Distributing value of variable to specific kernel

I want to distribute the value of a variable to a specific kernel in a parallel computing setup. Using DistributeDefinitions of course does the job, but it ...
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1answer
61 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 ...
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0answers
69 views

strange timing behavior

The following code is from a book about Mathematica. ...
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0answers
39 views

Shared variable impacting speed? [duplicate]

I am using a shared variable as a progress indicator ( via SetSharedVariable[counter] and then Dynamic[counter]), to keep track ...
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61 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: ...
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15 views

How can I set global computation options ($MaxPiecewiseCases) for parallel kernels? [duplicate]

I'm trying to do a calculation in parallel that requires setting $MaxPiecewiseCases. How can I do this? This small test case doesn't work for me: ...
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28 views

Notebook stops using extra kernels after some time

Have a mathematica .nb job where I've programmed to run on parallel. Everything goes fine for about an hour but after this most kernels just stop being used by the program. I can see this happing in ...
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55 views

Cluster integration: Problem connecting to Sun Grid Engine

I'm trying to launch some kernels in a cluster engine running Sun Grid Engine using Cluster integration. But I'm getting the error "Cannot find components required for SGE". ...
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1answer
44 views

A problem with parallelize

I am experimenting with Parallelize and ParallelTable This is the code I am using: ...
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45 views

Need to parallelize function f in a iteration

I don't have experience using Mathematica for parallel calculation. I need to do something simple to parallelize the calculation of f which is calculate each time n iterates: ...
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0answers
41 views

How to parallelize a the calculation of a vector function which is inside a recursive formula

I need some help with parallelizing the calculation of a vector function F which is inside a recursive formula. An example of the code is below for few iterations. ...
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61 views

How to parallelize this code

Here I obtained one code which should tests some zeros of the poly for various g, but sometimes I have to many cycles because of step and I need to parallelize the running on all cores. Classical ...
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30 views

KernelObject::rdead on local kernels

I'm trying to parallelize some tasks which involve fetching data from a URL and processing it. This is the code: ...
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584 views

Fastest way to create a NxNxNxN dimensional matrix

I have a function that outputs a complex number Func[x_,y_]:= blah blah; I have constructed a table of all possible values of this function. ...
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44 views

Aborting Multiple Trial Divisions if a Factor is found

I am using Mathematica to perform trial divisions on large Mersenne numbers using specific prime numbers (e.g., primes of the form 8n+1 or 8n-1) and would like the program to abort once a factor is ...
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63 views

coding simple structures, potential problems (multithreading) and how to solve them

This post contains two parts. In the first part I will explain what I am trying to do. In the second part I will explain what I fear. My questions are about these fears. Are they justified and if yes ...
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19 views

save data in parallel table [duplicate]

Suppose we have a table such as: Table[a[i,j]= 3 i^2+5 j,{i,1,100},{j,1,1000}]; after running this command we will have access to a[i,j], for example: ...
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32 views

Updating List with Do works but not with ParallelDo [duplicate]

I am trying to find 5 minimas for some function. I can obtain the results if I implement a simple Do function. I tried to speed it up by using ParallelDo and then my code returns spurious results. ...
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41 views

How to construct a list in a For Loop nested in a Parallel Loop [duplicate]

I've the following problem I cannot solve. I allocate an empty matrix, v, of size n x m. Then I want to do a Parallel loop (ex. ParallelDo), and do some operations (described by a function ...
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68 views

Parallelising the solving of polynomials

I'm working on finding solutions to a, not so very nice, system of equations. They are all polynomials of degree $4$ with $5$ parameters and all terms are of even order. I'll post the code on request, ...
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44 views

ParallelTable: explicitly assign iterator values to kernels

I've a construct that reads ParallelTable[ MyFunction[i], {i, 16} ] Now, MyFunction[i] takes an amount of time to be evaluated which is a decreasing function ...
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1answer
92 views

Problem with List Dimension Outer Map [duplicate]

I am currently handling a big list which has the following dimension: {6, 3, 4, 2, 2, 1, 8} where the last number 8 represent a ...
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108 views

Strange ParallelMap behavior

Let the symbol V denote an element of some vector space and nV its norm. Let lin be a linear ...
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1answer
157 views

How to use all the kernels efficiently

We build a project with Java and Mathematica technologies. For this project we have written a bunch of functions in Mathematica and integrated some functions in one ...