Fastest way for page-wise computation - FOR vs ARRAYFUN vs PAGEFUN

조회 수: 8 (최근 30일)
Daigo
Daigo 2022년 5월 6일
댓글: Joss Knight 2022년 5월 9일
I'd like to know the fastest way to deal with a 3D array in a page-wise way. Suppose I have the following data:
rng(0);
data = randi([1, 10], 10, 10, 1000); % sample data
and I want to know the inverse matrix of each page of this data. I compared three approaches to compute this:
% Approach1 - FOR loop
tic;
data_inv1 = zeros(10,10,1000);
for ii = 1:size(data,3)
data_inv1(:,:,ii) = inv(data(:,:,ii));
end
time1 = toc;
% Approach2 - Arrayfun
tic;
data_inv2 = arrayfun(@(ii)inv(data(:,:,ii)), 1:size(data,3), 'UniformOutput', false);
time2 = toc;
% Approach3 - Pagefun
tic;
data_gpu = gpuArray(data);
data_inv3 = pagefun(@inv, data_gpu);
time3 = toc;
% Comparison of elapsed times
fprintf('FOR-loop: %.8f sec\n', time1);
fprintf('Arrayfun: %.8f sec\n', time2);
fprintf('Pagefun: %.8f sec\n', time3);
The results on my computer are shown below:
FOR-loop: 0.01121580 sec
Arrayfun: 0.01491200 sec
Pagefun: 0.01317000 sec
Surprisingly, the use of the for-loop was the fastest. I expected that pagefun will give me the fastest computation but that was not the case.
Has anyone tried different approaches to speedup the page-wise computation? Is there anyway to make a good use of pagefun?
  댓글 수: 4
dpb
dpb 2022년 5월 7일
Yes...sorry, I intended as the additional overhead with the higher-level constructs, not the inherent memcopy of addressing planes.
In theory, MATLAB should be able to address data(:,:,ii) in place without the explicit copy.
Joss Knight
Joss Knight 2022년 5월 9일
What GPU do you have? I suspect pagefun will be faster if you process in single precision.

댓글을 달려면 로그인하십시오.

답변 (0개)

카테고리

Help CenterFile Exchange에서 Loops and Conditional Statements에 대해 자세히 알아보기

태그

제품


릴리스

R2020a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by