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4
votes
1answer
63 views

Apply ParallelMap to function f over a matrix while passing as arguments the row number and the element index

I have a matrix test = { {2.5,1.4,3.3},{4,4,4},{7,3.2,9}} and a function f that requires 2 arguments, the row number and the ...
0
votes
1answer
123 views

Want advice on writing better code to do matrix calculation [closed]

I want to perform the computation shown in the code given below in a much faster way. I have three loops for e, i and ...
1
vote
1answer
66 views

Optimising matrix calculation [closed]

I was calculating the elements of a matrix like this: ...
1
vote
0answers
138 views

Possible to use all cores for FullSimplify-ing elements from a matrix or vector? [closed]

I understand that FullSimplify, in general, uses one core only. However, when you FullSimplify a matrix or vector, I'm guessing Mathematica simplifies each element independently of the rest, so... why ...
0
votes
1answer
117 views

Running out of memory when dealing with 210 million matrix elements

I have a program for counting pixel elements in RGB with a precision of two decimal places. Each image consists of 280 x 250 pixels, and the images are stored in a folder containing 1200 images. At ...
2
votes
0answers
79 views

Parallelizing code, any tips?

I have access to a Linux cluster and I'm trying to use Parallelize to run the above bellow faster, but whenever I try to place ...
3
votes
2answers
175 views

Accelerating the construction of a ParallelTable

I wish to calculate a rather dense antisymmetric matrix quite fast based on a random distribution of points (and their radii) in the three dimensional space as follows: ...
2
votes
1answer
85 views

How to fill in matrices by enforcing a condition on each entry quickly?

In the process of solving a 3D time-dependent PDE, I need to fill several matrices which their sizes are quite high. These matrices are constructed based on the radii of the mesh nodes in the 3 ...
6
votes
1answer
269 views

Calculate the ESP Grid based on Density Grid

I want to build a fast way to convert a density grid file into a grid file of the respective electrostatic potential (ESP; also known as MEP, the molecular electrostatic potential). This calculation ...
3
votes
1answer
181 views

How to speed up filling a matrix as much as possible in a loop?

In order to find the solution of an $n\times n$ system of nonlinear equations by the method $x_{k+1}=x_k-D_k^{-1}f(x_k)$ where $D_k$ is an approximation of the Jacobian and defined by \begin{equation}...
1
vote
2answers
156 views

How to parallelize this code?

Initialize a matrix a with value of $\alpha$ in central cell as "ice", and $\beta$ in every other cell. ...
2
votes
0answers
339 views

Parallel evaluation of symbolic matrix eigenvalues

I'm trying to find eigenvalues of symbolic hermitian 40x40 block matrix. It is made from 20 2x2 matrices like this: ArrayFlatten[Table[M[m,n],{m,1,20},{n,1,20}]] ...
4
votes
1answer
164 views

Eigensystem on HPC

I am submitting Mathematica jobs to an HPC. I have a large matrix that is a function of (x,y) and I am diagonalizing it for around 500 points in the plane. My initial idea was to request a node with ...
14
votes
1answer
476 views

Making Monte Carlo simulation with ParallelTable

I would like to to MonteCarlo simulations of various regressions - basically, doing OLS under various conditions to test approaches. On my macpro 2x 2.8 GHz quad core Xeon, 32 Gb RAM DDR2 @ 667 Mhz, ...
6
votes
0answers
378 views

Discriminant of Characteristic Polynomial [closed]

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 ...
3
votes
2answers
796 views

Is there a way to parallelize the convolution component of EdgeDetect?

Provided an image like - test = Import["http://upload.wikimedia.org/wikipedia/commons/d/d5/Sunflowers.jpg"] We can run ...
6
votes
1answer
657 views

Is matrix multiplication automatically done in parallel in Mathematica 9?

In good old Mathematica versions (5.2, 6.0), matrix multiplication was automatically done in parallel. For example, on an 8-core machine, define two square real matrices: ...
0
votes
1answer
480 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 ...
12
votes
1answer
2k views

Nesting Parallel processes

I just attempted to run code that had nested ParallelMap[] functions. It generates the error message: ParallelMap::subpar: Parallel computations cannot be nested; proceeding with sequential ...