Problem reading lines from .dat file

Question

Denis Wolff 2018-5-16

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https://ww2.mathworks.cn/matlabcentral/answers/400985-problem-reading-lines-from-dat-file

回答： Denis Wolff 2018-5-16

Hello,

I want to read a .dat file into matlab line by line, using a function like 'textscan' or 'sscanf'. Each line looks like the following:

3,424, 10:50:34.177, 0, 2,863333, 1,478, 54, 127,7047, 90,19555, 0, 0, 0,7567907, 3479,262, 16,07539, 0, 108, 228, 48, 1,046861, 1,067549, 0, 1,096976, 123, 88, 1613,094, 56449,5, 6, 0,5, 103,0865, 0

What is inconvenient is that the commas (',') are used both as delimiters and for the decimal places. Apparently this causes an error when reading the line, for instance when I'm using

 textscan(tline,'%f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f','Delimiter',', ','EmptyValue',-Inf);

it seperates the "3,424" into "3" and "424". I tried using different options for Delimiter , as ', ' or ',\b' to make clear that the numbers are seperated by a Comma+Empty Space, but I couldn't find any way to tell Matlab that there are two types of commas and that it shoud seperate '3,424' from '10:50:34.177' but not '3' from '424'.

Can anyone please help me correctly reading these lines into Matlab?

Many thanks, Denis

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Answer 1

Jan 2018-5-16

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编辑：Jan 2018-5-16

在 MATLAB Online 中打开

Using commas as decimal point and separator of the data is not only "inconvenient", but a disaster. The trustworthy solution is to delete the files and recreate them with a reliable dot.

There is one chance, that the commas used as separators are followed by a space in every case. Is this true? Then you can fix the files:

S = fileread(FileName);
S = strrep(S, ', ', '<magic!>');
S = strrep(S, ',', '.');
S = strrep(S, '<magic!>', ', ');
fid = fopen(FileName, 'w');
fwrite(fid, S, 'char');
fclose(fid);

By the way, I'd use '%s' or even better '%D' to import '10:50:34.177' .

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Answer 2

Denis Wolff 2018-5-16

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Great, that's the solution! I could fix the files (it wasn't my choice to respresent them this way, but fortunately the commas are followed by a space in every case).

Thank you very much!