csvwrite is storing wrong number
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I'm using "csvwrite" command for storing a 2d matrix with size 104937*1810. Is there any limitation on this command or csv file? The produced file is 670 MB but in each stored row there are exactly 5 numbers which are not the same as matrix in the matlab. All numbers are int32 and the wrong numbers are in different colomns in each row.
1 Comment
Walter Roberson
on 25 Jan 2019
Would it be possible to xlswrite() or writetable() to a .xlsx file and attach that for us to test with?
Also which release are you using?
Accepted Answer
dpb
on 26 Jan 2019
Edited: dpb
on 26 Jan 2019
>> tstary=int32(randi(2^31,104937,1810));
>> whos tstary
Name Size Bytes Class Attributes
tstary 104937x1810 759743880 int32
>> tstary(1:3,1:5)
ans =
3×10 int32 matrix
1186639717 717774140 2035668545 471416973 522550194
2056308186 151423171 131112521 1937130594 1414722413
1917344954 1185569608 203068410 614639920 243357862
>> csvwrite('tstary.csv',tstary)
Content of tstary.csv from file viewer...
1.1866e+09,7.1777e+08,2.0357e+09,4.7142e+08,5.2255e+08,1.1246e+09,1.5343e+09,3.2607e+08, ...
2.0563e+09,1.5142e+08,1.3111e+08,1.9371e+09,1.4147e+09,7.5605e+08,7.9947e+08,6.188e+08, ...
1.9173e+09,1.1856e+09,2.0307e+08,6.1464e+08,2.4336e+08,9.5385e+08,1.0362e+09,2.0352e+09, ...
...
The content is exactly what the documentaion for csvwrite says it will be--the data in %g format with a maximum of 5 digits of precision.
The help there indicates to use dlmwrite with optional precision argument, but for such a large file, using a text format is absurd way to store/move/transport data. Use stream or some other form instead.
But, csvread is working as expected.
3 Comments
dpb
on 26 Jan 2019
Edited: dpb
on 28 Jan 2019
I misunderstood initially, too, I think, but decided that probably it was a case of the symptom not being recognized as to cause that produced a mistaken interpretation of the cause of the difference and that led to asking the wrong question--or wording the question to be about the wrong problem.
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