Creating a big Variable with splitting into numbered .mat-Files
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Hello Guys, i need to create a "big" Variable but my Memory(4GB) is not big enough so i want now to split it into some numbered .mat-Files. With this code i would have the Variable Buff with 6.765.201 rows and 4 columns:
Buff = zeros(numel(1350:2:1450)*numel(-150:2:-50)*numel(825:2:925)*numel(1225:2:1325),4);
Ctr = 1;
for step1 = 1350:2:1450
for step2=-150:2:-50
for step3=825:2:925
for step4=1225:2:1325
Buff(Ctr, 1) = step1;
Buff(Ctr, 2) = step2;
Buff(Ctr, 3) = step3;
Buff(Ctr, 4) = step4;
Ctr = Ctr+1;
end
end
end
end
But i want that matlab create Buff with 1 to 500.000 rows and 4 columns into saving_Buff_001.mat then the next 500.000 to 1.000.000 rows and 4 columns into saving_Buff_002.mat and 1.000.000 to 1.500.000 to saving_Buff_003 and so on...
My idea was something like this, but matlab creates first the big variable and then starts splitting
idx = mod(Ctr-1,500000)+1;
if idx == 500000
index = Ctr/500000;
save(sprintf('saving_Buff_%03d.mat',index),'Buff');
end
Hope somebody can help my, big thanks
2 个评论
per isakson
2013-1-12
memmapfile might be a better alternative
Matt J
2013-1-12
With this code i would have the Variable Buff with 6.765.201 rows and 4 columns.
A matrix of that size is only 206 MB. Should be no problem for a system with 4 GB RAM.
回答（2 个）
Matt J
2013-1-12
In addition to memmapfile, there is also matfile, and you could put the whole thing in one file. No need to split into multiple files, as far as I can see, though I would recommend writing column-wise instead of row-wise
matObj=matfile('myfile','Writable',true);
for i=1:4
matObj.Buff(:,i)=...;
end
Trier87
2013-1-12
0 个投票
2 个评论
José-Luis
2013-1-12
Do you really need so large a variable in memory? Could you not just load what you need? Also, in the future, please don't place comments as answers as it might get confusing for those trying to join the discussion.
Jan
2013-1-12
@Trier87: Please do not post comments as answers.
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