CODEWITHSUNDEEP
performancematlabload
kiara
kiara

Reputation: 222

Mat file loads slower than m-file

I have a large variable stored in a mat file and in a .m file. The data is just a big cell: 

Tensor{1,1,1,1,1,1,1,1,1,1,1,1}=[1,1,2,2,1, (... )];

Tensor{1,1,1,1,1,1,1,1,1,1,1,2}=[1,1,2,2,3, (... )];

(...)

Why it is so much slower to load the variable form the mat-file, than from the m-file? 

tic;load('Tensor.mat');toc
Elapsed time is 6.969654 seconds.

tic;Tensor;toc
Elapsed time is 0.152476 seconds.

Is there a way to save variables as m-files?

@Daniel An example of a typical entry is:

Tensor{2,2,2,2,2,4,4,4,4,4,4,4} = [ ...
    0,0,0,0,0,(1 / 6) .* 22 .^ (-1 / 2),0,0,0,0,0,0,0 ; ...
    0,0,0,0,(1 / 6) .* ( 5 / 33) .^ (1 / 2),0,(-1 / 12) .* (7 / 11) .^ (1 / 2),0,0,0,0,0,0 ; ...
    0,0,0, (1 / 11) .* (5 / 6) .^ (1 / 2),0,(-35 / 132) .* 3 .^ (-1 / 2),0,(7 / 44) .* 3 .^ (-1 / 2),0,0,0,0,0; ...
    0,0,(1 / 11) .* (5 / 6) .^ (1 / 2),0,(-7 / 33),0,(1 / 44) .* 105 .^ (1 / 2),0,(-7 / 66),0,0,0,0; ...
    0,(1 / 6) .* (5 / 33) .^ (1 / 2),0,(-7 / 33),0,(7 / 33) .* (5 / 2) .^ (1 / 2),0,(-35 / 198) .* (5 / 2) .^ (1 / 2),0,(7 / 66),0,0,0; ...
    (1 / 6) .* 22 .^ (-1 / 2),0,(-35 / 132) .* 3 .^ (-1 / 2),0,(7 / 33) .* (5 / 2) .^ (1 / 2),0,(-25 / 66) .* (7 / 6) .^ (1 / 2),0,(35 / 198) .* (5 / 2) .^ (1 / 2),0,(-7 / 44) .* 3 .^ (-1 / 2),0,0; ...
    0,(-1 / 12) .* (7 / 11) .^ (1 / 2),0,(1 / 44) .* 105 .^ (1 / 2),0,(-25 / 66) .* (7 / 6) .^ (1 / 2),0,(25 / 66) .* (7 / 6) .^ (1 / 2),0,(-1 / 44) .* 105 .^ (1 / 2),0,(1 / 12) .* (7 / 11) .^ (1 / 2),0; ...
    0,0,(7 / 44) .* 3 .^ (-1 / 2),0,(-35 / 198) .* (5 / 2) .^ (1 / 2) ,0,(25 / 66) .* (7 / 6) .^ (1 / 2),0,(-7 / 33) .* (5 / 2) .^ (1 / 2),0,( 35 / 132) .* 3 .^ (-1 / 2),0,(-1 / 6) .* 22 .^ (-1 / 2); ...
    0,0,0,(-7 / 66), 0,(35 / 198) .* (5 / 2) .^ (1 / 2),0,(-7 / 33) .* (5 / 2) .^ (1 / 2),0,( 7 / 33),0,(-1 / 6) .* (5 / 33) .^ (1 / 2),0; ...
    0,0,0,0,(7 / 66),0,(-1 / 44) .* 105 .^ (1 / 2),0,(7 / 33),0,(-1 / 11) .* (5 / 6) .^ (1 / 2),0,0; ...
    0,0,0,0,0,(-7 / 44) .* 3 .^ (-1 / 2),0,(35 / 132) .* 3 .^ (-1 / 2),0,(-1 / 11) .* (5 / 6) .^ (1 / 2),0,0,0; ...
    0,0,0,0,0,0,(1 / 12) .* (7 / 11) .^ (1 / 2),0,(-1 / 6) .* (5 / 33) .^ (1 / 2),0,0,0,0; ...
    0,0,0,0,0,0,0,(-1 / 6) .* 22 .^ (-1 / 2),0,0,0,0,0 ...
    ] ;

Upvotes: 3

Views: 156

Answers (1)

freude
freude

Reputation: 3832

That is because the .mat-file is a binary file that requires some processing to extract a variable, while the .m-file is nothing else just a text file. Instead of .m-file it is more convenient to save data in .dat-file. The result should be about the same. This can be checked trying these two commands:

tic;load('Tensor.mat');toc
tic;load('Tensor.dat','-ascii');toc

Upvotes: 1

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