Questions on parallel computing in Mathematica.

learn more… | top users | synonyms

23
votes
1answer
481 views

Is it safe to launch/close kernels in the middle of a parallel calculation?

It appears that it is possible to launch additional kernels (or close existing ones) during a parallel calculation. The newly launched kernels will be utilized for the rest of the calculation. ...
1
vote
1answer
94 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 ...
7
votes
0answers
225 views

Using Compile to speed up Function with PermutationProduct

I have the following fairly simple routine dot involving PermutationProduct that I wish to speed up using ...
5
votes
0answers
66 views

Experimental`NumericalFunction in NMinimize solution

I try to make a number of optimizations using this code: ...
5
votes
0answers
72 views

What do the elements of the Parallel Kernel Status screen mean?

I just managed to get my multiple kernels up and humming on a new multi-core machine, which I am quite happy about. I am slightly at a loss, though, about the meaning of the different parts of the ...
5
votes
0answers
180 views

Parallelizing is much slower than single kernel evaluation?

Starting with a vector of matrices, tVec, I would like to parallelize the multiplication of each element with the same matrix ...
4
votes
0answers
92 views

Discriminant of Characteristic Polynomial

I'm doing a calculation which finds the characteristic polynomial of a matrix with rather complex entries and then determines the discriminant of that polynomial. For smaller matrices up to around 7x7 ...
4
votes
0answers
168 views

Does `Eigenvalues` evaluate in a parallelized way?

I use mathematica on a computer with linux operating system. The computer has 2 cpus and each cpu has 4 cores, so there are totally 8 cores available. Now I got confused with whether the evaluation ...
4
votes
0answers
131 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 ...
3
votes
0answers
77 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
votes
0answers
137 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
0answers
46 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 ...
2
votes
0answers
121 views

Remote kernel shuts down after several seconds

I have Mathematica 9 installed on two Windows Server 2008 R2 machines. Now i want to try using one of them as a frontend with local kernels and the other one for remote kernels. OpenSSH 6.5 for ...
2
votes
0answers
81 views

Whether NIntegrate evaluation is multithreaded or not?

About MultiThread evaluation I am talking about here, see this post I am NIntegrate the function grarm[e, 3, dimension, 1, 1, 0.005]. There is matrix operation in ...
2
votes
0answers
53 views

Setting Up Lightweight Grid On Multiple Clients Programmatically

I have a number of computers which all might need to use the same (client) configuration for the Wolfram Lightweight Grid at some point. I know that there are ways to programmatically set certain ...
2
votes
0answers
60 views

How can you link Parallel Mapping and Error tracking

Following this question and the comments made, together with the information in this question, the following code allows error tracking and debugging very nicely. ...
2
votes
0answers
112 views

correct usage of ParallelTable

I am trying to parallelize my script. Here is a MWE of how I have done it: ...
1
vote
0answers
66 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 ...
1
vote
0answers
261 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 ...
1
vote
0answers
35 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 ...
1
vote
0answers
119 views

Optimization of power tower fractal generator

I tried to optimize the code for generating power tower fractals from here. As the author suggested, I tried to memorize the points already tested in a list. Here is my code : ...
1
vote
0answers
154 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 ...
1
vote
0answers
134 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 ...
1
vote
0answers
165 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)?
1
vote
0answers
167 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 ...
0
votes
0answers
45 views

Main Kernel in Mathematica

I would like to copy some parameter from the main Kernel of Mathematica to the parallel kernels available. So I'm running now a command like: ...
0
votes
0answers
47 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 ...
0
votes
0answers
22 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: ...
0
votes
0answers
145 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. ...
0
votes
0answers
39 views

Monitor progress of a ParallelMap computation

I think this question is very similar to http://stackoverflow.com/questions/7352461/monitoring-progress-of-a-parallel-computation-in-mathematica I have been a while trying to adapt that to my problem ...
0
votes
0answers
40 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 ...
0
votes
0answers
57 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 ...
0
votes
0answers
64 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, ...
0
votes
0answers
39 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 ...
0
votes
0answers
99 views

Strange ParallelMap behavior

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