MATLAB: How can I write a parallel code in Matlab

parallel computing in matlabParallel Computing Toolbox

hi every one, can you help me to write a program with parfor and compare the time consumed in comparing with for? The code is: matlabpool open local 7 tic parfor i = 1:100000 k=i end toc matlabpool close Elapsed time is 1.846197 seconds.

tic,for i = 1:100000 k=i end toc Elapsed time is 0.000640 seconds.

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The reason you are seeing this result is because your loop does not do anything. If you make each iteration of your loop do substantial work, you will see a speedup.

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MATLAB: How to create a sequence of numbers on the GPU

Found it.

gpuArray.linspace(1,1000,1000);
>> tic; for i = 1:10000; gpuArray(1:100000); end; toc;
Elapsed time is 2.737965 seconds.
>> tic; for i = 1:10000; gpuArray.linspace(1,100000,100000); end; toc;
Elapsed time is 0.916697 seconds.

MATLAB: Object Oriented Programming Performance Comparison: Handle Class vs. Value Class vs. no OOP

There is no way to change an object of a value class on method call, other than to return the updated object as a result, and assign it to the variable that held the old object.

This is a strength. One of the core features of MATLAB is its call-by-value semantics: with non-oop MATLAB you can never, for example, accidentally change the value of an array in one part of a program by an assignment to one of its elements in some remote part of the program. Bugs caused by such actions are one of the biggest problems, especially for beginners, in call-by-reference languages. By sticking to call-by-value, MATLAB must have saved countless thousands of hours of debugging time over the years.

However, handle classes break this, which in the context of MATLAB's normal programming model is dangerous. Therefore handle classes should, in my view, only be used when there is an overriding reason. One possible reason is to represent a unique object; another is to implement certain data structures which can only be efficiently updated with handle-class semantics.

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Related Solutions

MATLAB: How to create a sequence of numbers on the GPU

MATLAB: Object Oriented Programming Performance Comparison: Handle Class vs. Value Class vs. no OOP

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