Questions on parallel computing in Mathematica.
4
votes
1answer
55 views
Writing data to a common file during parallel processing
I am executing a loop, and in each loop I have to store a parameter in a file. It is like
...
1
vote
0answers
104 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 ...
4
votes
2answers
85 views
ParallelTable with nonstandard iterator
This works as expected:
Table[x[1], {x[1], 1, 10}]
However, the parallel version
ParallelTable[x[1], {x[1], 1, 10}]
...
2
votes
0answers
66 views
correct usage of ParallelTable
I am trying to parallelize my script. Here is a MWE of how I have done it:
...
2
votes
0answers
91 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 ...
0
votes
0answers
20 views
The parametric equations for $f(x)=1+\sin(x)/x$ [migrated]
What will be the the parallel curves of $f(x)=1+\sin(x)/x$ or how could I express the parametric equations for the function ?
1
vote
0answers
72 views
why ParallelDo do not do right?
I encountered a problem with ParallelDo. The code below is part of my program. It won't give the right answer. But as soon as I change ...
8
votes
2answers
144 views
Distribute and analyze large datasets
I need to analyze very large datasets, and they obviously don't fit in a computer memory. I need to produce some statistics on these datasets, and this brings me here:
How can I make some statistical ...
8
votes
1answer
194 views
How to run an external program in parallel with a Mathematica package?
Under Mathematica 8 (Linux x84_64) I was able to run an external program in parallel from a Mathematica package. However this procedure breaks down under Mathematica 9.
Within my Mathematica package ...
4
votes
2answers
116 views
Why is this parallel evaluation with Dispatch[] so slow?
Can you efficiently parallelize this? The parallel versions are much slower than the sequential version, and I'm not sure why. Does SetSharedVariable allow ...
1
vote
0answers
95 views
3
votes
0answers
89 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 ...
5
votes
0answers
117 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 ...
2
votes
0answers
75 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 ...
0
votes
0answers
82 views
Parallelization issues
I'm programming an algorithm where I have to evaluate, at each iteration, a characteristic of a subgroup of data. An evaluation of a subgroup takes 2-3 secondes and I have 200 sugroups to test per ...
2
votes
1answer
104 views
Mathematica 7: Problems when evaluating Fourier inside a ParallelTable
after I got such a great response for my first question on this site, I'm very encouraged to asked my second one!
So here it is, very generally: To speed up a "row-wise" (i.e. 1D) operation on a ...
2
votes
1answer
102 views
How can I prevent these warnings while using ParallelTable
I have this code to find all the permutations of a set of letters that form legal words.
...
4
votes
1answer
105 views
Launching remote slave kernels on HPC causes slow down
I had a post earlier regarding how I can run Mathematica at a HPC cluster (running PBSpro) by having a single MathKernel launch ...
3
votes
3answers
139 views
Efficient way to utilise Parallel features to make use of many cores
Let's say I have 100 cores/kernels as my disposal and want to compute a function of two variables f[x,y] over {x,1,10}, ...
2
votes
2answers
118 views
Parallelization of REvaluate[]?
Is there a way to run several RLink computations via REvaluate[] in parallel, e.g. with ParallelTable[]?
7
votes
2answers
177 views
Mathematica Parellelization on HPC
I'm currently using Mathematica on a High Performance Cluster (HPC) which consists of many compute nodes each with around 16 cores. I currently run my Mathematica script on 20 of the nodes that ...
2
votes
1answer
82 views
Mathematica 9.0 problem: ParallelTable with SQLExecute
I have run into the following problem: when I try to run the following code in Mathematica 9 I get SQL connection error on all kernels.
The code is:
...
0
votes
1answer
176 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 ...
9
votes
1answer
227 views
Parallelization and Hadoop
The short question: Has anyone used Mathematica in conjunction with Hadoop and does Mathematica's built in parallelization play well with Hadoop?
The long version:
So I have a Mathematica program ...
3
votes
2answers
202 views
why I can't define a commutator operator in this way？
I am trying to define some operators I used frequently.For example, I defined a KroneckerProduct operator as $ \otimes $ as follows:
a_$ \otimes $b_:=a.b-b.a
and this works fine.
Then I want to ...
3
votes
1answer
74 views
Determining the partitioning of Do loop iterations between kernels?
Say I have some Do loop that I'd like to evaluate in parallel: Do[Something, {i, 1, M}]. I'd like to split this list up into ...
1
vote
1answer
103 views
Understanding a slowdown associated with wrapping a set of nested Do loops with a ParallelDo expression
I have a set of set of nested Do loops that require data from three different arrays (though the position from each array is fixed per cycle of the outer Do loop). Let's call these arrays: ListA, ...
2
votes
1answer
73 views
Parallel computing NInverseFourierTransForm
I am running the code below, and it works perfectly. I have some function in Fourier space, and I take the numerical InverseFourierTransform. However, I will have ...
6
votes
1answer
64 views
Is it safe to use older version subkernels with a newer version main kernel?
At the moment we only have access to version 8 of the Lightweight Grid (i.e. version 8 of the Mathematica kernel). Is it safe to run version 8 subkernels together with a version 9 main kernel? It ...
3
votes
1answer
54 views
local logfiles for remote kernels
I'd like remote slave kernels to produce log files on my local machine, subject to the following constraints:
1) I don't want to install a distributed filesystem or do other administrative work on ...
2
votes
1answer
66 views
How can I set the kernel for CreatePalette?
I have written some code that requests some calculations from an SQL server every N seconds and uses a palette:
CreatePalette[Dynamic[DateListPlot[...]]]
I ...
11
votes
3answers
256 views
Suspecting bug in Parallel Framework
I've reduced my actual problem to:
ParallelEvaluate[
Module[{slot=1},
Slot[slot]
]
]
gives error messages that I think shouldn't be there. It seems I can ...
1
vote
1answer
234 views
3 hour calculation? ParallelMap & ParallelTable
I'm having some problems with slow Mathematica code... I'm basically doing a computation that's is expected to take 3 hours (!) in my Core i7 with 4 processors... I'm basically computing an index (of ...
6
votes
1answer
230 views
Export graphics in parallel
I run a heavy simulation, using NDSolve and the method of lines. This means that the result of NDSolve is a list of, say, ...
7
votes
1answer
193 views
how can I avoid CPU waste (by master kernel) using WaitNext?
I'm using WaitNext in Mathematica for parallel processing on Mac OS X. I have 4 processors on my MacBook and LaunchKernels[] ...
0
votes
0answers
149 views
Best Parallel Kernel Configuration
I wrote a code snippet which counts prime numbers in any given interval because the built-in PrimePihas a limited bounds.
...
0
votes
1answer
72 views
Draw from HistogramDistribution with ParallelTable
I wanted to check something, but ran into troubles using HistogramDistribution in combination with ParallelTable.
The code does the following: Compute a HistogramDistribution of some sample and use ...
7
votes
1answer
191 views
2
votes
1answer
188 views
Light Weight Grid and core limitation
I am trying to figure out what would be best for running some simulations using multiple computers where each has it's own mma 8 licence. The main part of the computation involves a parallelized table ...
2
votes
1answer
142 views
Progress indicator with shared variables
I'm trying to create a custom progress indicator for a parallelized computation, using Dynamic and SetSharedVariables to display ...
12
votes
2answers
290 views
Tell ParallelMap[] to use just specific kernels
Is there a way to tell ParallelMap to use just some specific kernels (as is possible for ParallelEvaluate)?
Background: I have ...
1
vote
0answers
139 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)?
2
votes
1answer
151 views
Why can't Mathematica parallelize this?
The following code makes mathematica print "ParallelTable::nopar1: [...] cannot be parallelized; proceeding with sequential evaluation."
...
1
vote
0answers
103 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 ...
6
votes
2answers
217 views
Use of Cellular Automaton or Discrete Convolution to calculate Potts Energy of a 2D Matrix
In a project of Monte Carlo Modelling of Grain Growth (Link) one of the most costly subroutines is the calculation of the Potts-Energy of an Monte Carlo Grid cell by comparing the center cell value ...
2
votes
1answer
202 views
using interpolation functions in ParallelMap
Edit
I am editing the question to give a simple workable example. It is at the bottom under the heading Example. The original question is now headed withe Background.
Background
I am trying to ...
2
votes
1answer
148 views
ParallelTable and Precision
I'm using ParallelTable[] to calculate a function over a range of my parameters , ($\omega,\ell$). This seems to be working well (in terms of speed increase) except ...
6
votes
0answers
104 views
Is there a way to convert mathematica code to OpenMP or OpenACC?
I see that Mathematica has limited support for things like OpenCL and CUDA, but what about other standards like OpenMP or OpenACC?
2
votes
1answer
108 views
Clearing distributed definitions from remote kernels
The documentation shows the following example to "Remove a distributed definition..."
Oh, course this doesn't work without redefining the function prior to re distributing the definition. The ...
7
votes
1answer
277 views
Communication between parallel kernels
Greetings. This is my first post here, also, I am not a seasoned programmer, so any advice pertaining to coding that is not directly related to the problem (stated below) is welcome. I am having ...
