how to use "save" matlab

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Daniel Barzegar
Daniel Barzegar on 19 Jun 2014
Edited: dpb on 19 Jun 2014
Hi all, i create a very big file in matlab and then i try to write it in a txt file using the fprintf() function. But after a while a message pops up saying that there is not enough memory or sth like that.. How can i save it in the txt file? Can i use the save function of matlab to do that?
thanks. Daniel
  12 Comments
Daniel Barzegar
Daniel Barzegar on 19 Jun 2014
i looked at the Workspace window and it seems that only the tAcc has values in it. The other 4 are empty (the same happens for the res_t*.data). any ideas why is that happening?
dpb
dpb on 19 Jun 2014
The other files don't exist or are somewhere else, maybe? Hard to say from here, you'll have to poke around at the command line and see what's what...

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Accepted Answer

dpb
dpb on 19 Jun 2014
Edited: dpb on 19 Jun 2014
for i=1:size(res_tAcc.data,1)
fprintf(fid, '%f ', res_tAcc.time(i,1));
fprintf(fid, '%f %f %f %f %f %f %f %f %f %f %f %f %f %f %f', ...
res_tAcc.data(i,1)', res_tAcc.data(i,2)', res_tAcc.data(i,3)', ...
res_tGyro.data(i,1)', res_tGyro.data(i,2)', ...
..
Index exceeds matrix dimensions.
Error in resample2 (line 44) fprintf(fid, '%f %f %f %f %f %f %f %f %f %f %f %f %f %f %f', res_tAcc.data(i,1)', ...
You're running the loop over size(res_tAcc.data,1) but there's no guarantee that the others are necessarily identically the same size -- it appears at least one isn't as large.
Use size() on all the arrays you're wanting to output and ensure they're all at least as long as the one you've use.
BTW, for simplicity, a couple of things -- use repmat to make format strings manageable--
fmt=repmat('%f',1,15);
fprintf(fid,fmt,...
You can find the repeat count programmatically as well to save manual counting.
Also, build the array and output in one pass...
fmt=repmat('%f',1,16);
fprintf(fid,fmt,[res_tAcc.time(:,1) res_tAcc.data(:,1:3) res_tGyro.data(:,1:3) ...
res_tMagn.data(:,1:3) res_tOr.data(:,1:3) res_tRotQuatr.data(::3)].');
It would be even simpler and more regularly formatted if used dlmwrite or similar.
ERRATUM:
Also, build the array and output in one pass...
fmt=[repmat('%f',1,16) '\n'];
Forgot to add the newline...

More Answers (1)

José-Luis
José-Luis on 19 Jun 2014
Edited: José-Luis on 19 Jun 2014
your_data = rand(60000,16);
fid = fopen('data.txt','w');
fprintf(fid, [repmat('%f ',1,size(your_data,2)) '\n'], your_data)
fclose(fid)
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