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proper way of reading data from text file

Asked by sermet on 31 Dec 2016
Latest activity Edited by Stephen Cobeldick on 31 Dec 2016
The attached file is example data file. I need to store each element of line 2-3, 5-6, 8-9. The original file is bigger than this example. How can I store these numeric values of the related lines?

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1 Answer

Answer by Stephen Cobeldick on 31 Dec 2016
Edited by Stephen Cobeldick on 31 Dec 2016
 Accepted Answer

Here is one easy way to get all of that data into one matrix, using fileread and sscanf:
>> str = fileread('data.txt');
>> vec = sscanf(str,'%f');
>> mat = reshape(vec,[],3)'
mat =
Columns 1 through 7
4 1 2016 3570 1 1 1
4 1 2016 3600 2 -4 1
4 1 2016 3600 3 5 1
Columns 8 through 14
4 1 2016 1519.3 0 0 0.00014496
4 1 2016 6786.1 0 0 -0.00016785
4 1 2016 11876 0 0 -5.722e-005
Columns 15 through 20
0.76367 0.0064783 0.14664 0.0004673 -2656.4 0.00073242
0.64332 0.0091085 -0.69379 0.0012169 -2656.1 0.00067139
0.52564 0.0081682 -0.65228 0.001173 -2656.2 0.00073242
To automatically detect how many groups there are you could do something like this:
>> grp = numel(regexp(str,'^\d\d\s+\d\d\s+\d{4}\s+\d{4}\s*$','lineanchors'))
grp =
3
>> mat = reshape(vec,[],grp)'
Note that this method assumes that your data is all numeric, and that every group contains exactly the same number of values.

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