Questions tagged [parallelization]
Questions on parallel computing in Mathematica.
658
questions
2
votes
1answer
15 views
Parallel Computation with the possibility of calculation failure
I would like to use Mathematica to speed-up a parallel calculation.
I envisage each sub-process producing a list of 4 million machine reals. My problem is that sometimes the sub-process (based ...
0
votes
0answers
11 views
Parallel evaluate a cell distributing the definitions
In Cell evaluation and parallel kernels a solution is proposed for how to evaluate multiple cells in parallel. I tried it, but ran into the problem that definitions do not get distributed to the new ...
6
votes
1answer
123 views
Speeding up tensor contractions and multiplication
Consider a tensor $T\in\mathbb{R}^{N\times N\times N\times M}$ and two vectors $x,y\in\mathbb{R}^N$. I want to compute the $N\times M$ vector defined by $X_{ij}=\operatorname{tr}(x^\top T_{:,:,i,j}y)=\...
0
votes
0answers
22 views
Having trouble distributing a large association to sub-kernels
The following seems to work based on memory usage.
...
0
votes
0answers
28 views
1
vote
1answer
61 views
Parallelization command possible bug
In the following Mathematica compiled program, 3 persons take turns in a fair Russian Roulette Game with 1 bullet in the 6th chamber and we find the probabilities of each person being killed after 1,...
2
votes
0answers
42 views
Possible bug ParallelDo (or better practices for ParallelDo)
ParallelDo is having problems evaluate an expression that evaluates fine outside ParallelDo. The problem is not due to the use ...
1
vote
0answers
65 views
How can I devote all the cores to Mathematica?
I have a problem with the calculations speeds in xAct package. In fact, some of them take lots of seconds. Is there any way to speed up the calculations by engaging all the cores for Mathematica (or ...
2
votes
1answer
71 views
Passing Package Dependencies to Subkernels
Say I have a function f[x_,...]:=... in a *.wl-Package form that depends on a bunch of Packages (some other *.wl files), and say I want to call this function ...
0
votes
1answer
44 views
How to build a matrix of size n + 4 from a matrix of size n and 4 rows and 4 columns?
I have a matrix size n + 4 very long and very complicated and to find my matrix I have a matrix of size n and 3 rows and 3 columns
To better understand my problem here is a simple example
...
3
votes
0answers
27 views
ParallelDo and Reap/Sow in combination fails
I just realized the following problem. I tried to speed up a program that reads hundreds of files each of size up to 200+ MB and processes them, therefore I changed a ...
1
vote
0answers
117 views
Surprise: I don't need a new kernel to make to MMA notebooks independent [closed]
People seem to suggest that one needs to start a new kernel to keep multiple Mathematica (MMA) notebooks independent e.g. Kernel management link. But I did not do so and still found my two notebooks ...
7
votes
2answers
75 views
Parallelizing MapAt
What is the best way to parallelize MapAt? Only ParallelMap is provided, but seems bad when executing functions on a subset of a ...
0
votes
1answer
67 views
How do I share my variables and my function output in parallel computing?
Here as a simple example
...
0
votes
0answers
37 views
Parameter sweeps on a HPC cluster
I have a mathematica *.wl file set up, such that there are a couple of parameters defined in the beginning, and, when run, it produces a few outputs. I can run this script on a Slurm-run HPC cluster ...
3
votes
0answers
79 views
Parallel evaluation of RandomVariate for an InterpolatingFunction
I need to generate a lot of point according to a given distribution. I don't have an analytic form of this distribution so I am using an InterpolatingFunction of ~100 points computed numerically. I ...
0
votes
1answer
50 views
Parallel XML import
I need to import some xml information from many pages. I have list of this pages. Doing it in single thread is too long. But I can't access multiple pages from the same IP at the same time. So I need ...
0
votes
0answers
16 views
Parallezation gives LaunchLocal::somefail
I was running a program using parallelization, and I got the following warning message:
LinkOpen::linke: No MathLink problem encountered..
SubKernels`LocalKernels`LaunchLocal::somefail: 1 ...
1
vote
0answers
57 views
0
votes
0answers
76 views
0
votes
0answers
27 views
Saving DownValues for a function computed in parallel
Is it possible to save DownValues of a function computed using a parallelization routine?
I have a rather costly function f I wish to evaluate at a grid and save ...
2
votes
2answers
170 views
Parallel Computing Problem [closed]
The program runs out quickly(30 seconds) if I don't do parallel.But when I replace Table with ParallelTable,the Program will keep running,no output results.
My code
https://privatebin.net/?...
5
votes
1answer
104 views
Which version of Mathematica did DiracDelta become to the derivative of HeavisideTheta from that of UnitStep?
The mathematica's version of my coworkers is 5.0, they use UnitStep to derive formula, However, I also want to use the parallel features so used the latest version ...
0
votes
1answer
51 views
Parallelizing nested for loops
I'm currently computing nested for loops.
I count up a few counting variables and compute a value for each set of counting variables, then that value is added to an array. It is a way of adding up ...
0
votes
0answers
31 views
Reading a chunk of data from a stream using Parallelization
I am trying to read a stream and perform some operations in parallel. Here is the logic of the code inside the ParallelDo:
1- Open stream
2- Read chunk of data
3- Close stream
4- Process the data
...
5
votes
1answer
528 views
1
vote
1answer
105 views
How to run multiple functions simultaneously by multi-core CPU in Windows?
There exist multiple functions, take them for instance, 3 functions as follows:
...
3
votes
1answer
47 views
PatternTest vs Parallelization
Bug introduced in 10.0 or earlier and fixed in 11.2
Consider the following function
...
0
votes
1answer
69 views
Parallelise numerical integral for contour plot
I have the following integral that I would like to evaluate:
...
5
votes
0answers
110 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 "...
1
vote
0answers
44 views
Conversion of STL files to 3D Images
I am trying to convert some stl files to 3d images in MMA 11.3. I came across this post that contained some code making use of parallelization to speed up the process, as follows:
...
1
vote
0answers
37 views
How badly does switching kernel slow down or completely stop Mathematica running jobs?
I have a question on how to run two or more Mathematica jobs on one laptop. For example, I use a local kernel to run a job. Then I open another job and choose Kernel configuration option and choose ...
6
votes
1answer
69 views
How to properly Abort from within a ParallelMap?
If a condition is met within a sub-kernel in the function being mapped, how does one cancel the whole ParallelMap operation?
...
1
vote
0answers
46 views
Privilege violation for file or directory
hopefully somebody can help me out with the following;
I have a mathematica .wl script which uses ParallelTable;
When I run this locally (laptop) it works ...
0
votes
1answer
59 views
Update initial conditions recursively/sequentially within ParallelTable using NDSolve
I am modelling 3D motion of particles inside a force-field using second-order coupled PDEs, which I solve from time t=t0 to t=t1 with initial conditions x0,y0,z0. I have a total number of "particles" ...
3
votes
1answer
108 views
Why does choosing the method break the parallel computation? [closed]
I have a workable function with using NDSolve with predefined method for solving. But for some reasons I should use the parallel computation. The main problem is that the NDSolve can't build the ...
2
votes
1answer
67 views
ParallelMap vs building pure function on the fly
I have a case where one function builds a pure function whenever it is evaluated. A (admittedly contrived) example would be
...
0
votes
0answers
25 views
ParallelTable fails to finish evaluating after completing computation
I am executing a ParallelTable but the code fails to finish. This is the setup. f is a function.
...
1
vote
0answers
42 views
Clustering different kernel versions
After a good bit of trial and error I have managed to cluster together two OS X machines. The master is running Mathematica 9.0 and the secondary 11.0. All was well and good, the remote command being
...
3
votes
1answer
339 views
Parallele Computing - 2 vs. 4 processor speed [closed]
I am evaluating a code which ends with Table having ParallelEvaluate of a function XXXX[phi, theta, si]. For a grid of 225 ...
1
vote
0answers
62 views
WSTP with an MPI application
I'm looking to use WSTP to make functions defined in a C MPI application available to a remote Mathematica kernel.
I've got this working for a non-MPI version of the application, but now wish to have ...
3
votes
1answer
61 views
How to trigger WhenEvent for NDSolve in parallel?
Say I have a system of differential equations that I need to solve for different initial conditions and say the process is sufficiently expensive and I have sufficiently many that I am calculating in ...
15
votes
2answers
243 views
DistributeDefinitions is evaluating the definitions, and this only for a large number of definitions
I am using Mathematica 11.3 and this seems to me to be a bug. I would like, if possible, some idea on a workaround.
Here is an example of a trivial code that works as expected:
...
4
votes
1answer
174 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:
...
1
vote
1answer
39 views
Using ExternalEvaluate within ParallelDo
I have had great success using Python in Mathematica (for some computations for which there are very well optimised Python packages but not for Mathematica). I have some Mathematica functions that are ...
1
vote
1answer
82 views
Is there any way to save time using of “Cross” or “Table”?
I need to solve a equation by NDSlove, so I write the equation first, but it takes me a lot of time.
The follow is my code
...
0
votes
0answers
72 views
CUDAQ::internal: CUDALink experienced an internal error
I have Mathematica 11.0.0 installed on Windows 10, with an NVIDIA GT 630M GPU on my Dell Inspiron.
I am trying to run the CUDA examples in the Help files. All of the setup functions for CUDALink work ...
0
votes
0answers
34 views
Fail to modify the elements of a global vector in ParallelTable
I want to modify a vector in a Table function, such as
vec = {0, 0, 0, 0};
Table[vec[[i]] = i, {i, 1, 4}];
vec
// output {1,2,3,4}
however, when I use ...
0
votes
0answers
31 views
3
votes
1answer
60 views
ParallelDo gives different solution to Eigensystem
I am trying to calculate the eigensystem of a large matrix (e.g. 256x256). I have found that when I do this within a ParallelDo (because I am actually calculating many of these eigensystems), the ...
