Resave a Matlab file with v7.3 option

Hello,

I have few huge files with many substructures inside. I need to partially modify the content. I'm using matfile with option "'Writable',true".

I'm getting a lot of errors because although the total file is less than 2Gb, apparently once uncompressed some array is over 2 GB:

"Warning: The file 'D:\work\capture_tool\dsp\ctt_platform\input\rawdata_toronto55_matrix7x5_70g_50taps.mat' was saved in a format that does not support partial loading. Temporarily loading variable 'Push'

into memory. To use partial loading efficiently, save MAT-files with the -v7.3 flag.

Warning: Variable 'Push' was not saved. For variables larger than 2GB use MAT-file version 7.3 or later. "

If i load and save, it adds another layer in the structure which is the name of the original variable i used to load. Therefore, my program can't access it again:

temp = load('orig.mat');

save('-v7.3','mod.mat','temp')

temp2 = load('mod.mat')

temp2 =

struct with fields:

temp: [1×1 struct]

How can i automatically resave the files with option v7.3 leaving the structure untouched?

Thanks

Riccardo

Answer 1

[Ridwan Alam]

The version option goes at the end on save():

save('mod.mat','temp','-v7.3');

While loading,

temp2 = load('mod.mat');
temp2 = temp2.temp;

[Riccardo Micci]

i don't think that solves the issue. Now i have special cases for the "modded" files.

Old files won't require "temp2 = temp2.temp;" but the new ones will.

So the main function will either fail with one or the other.

[Ridwan Alam]

First of all, which issue? the saving one or the loading one?

I guess you meant the loading one.

If you want to keep the original name, just use:

 load('mod.mat') % instead of assigning it to anything

[Riccardo Micci]

The issue is in the saving. I need to maintain the file behaviour but i needed it the new file format. So i can the modify internally the single items. I can't modify the source that uses the file i.e. the loading function.

The original code was assigning it to a variable so i must still do that.

[Ridwan Alam]

I am not sure if this helps:

save('mod.mat','-v7.3');

I am just a bit confused here, so even if you know that the "load" is causing issue, you still can't modify the files?

I don't think the save() function adds that extra structure layer. It's the load() function, when you assign the returned value to a variable.

[Riccardo Micci]

i see what you're trying to do and actually works. The right sequence of actions is:

clear all

load('matfile.mat');

save('matfile','-v7.3');

It's a bit clumsy but makes sure the new file only includes data from the original one.

[Ridwan Alam]

Cool!! Glad to help!

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