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Read a .txt except one column

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Thomas DENIS
Thomas DENIS on 19 Mar 2016
Closed: MATLAB Answer Bot on 20 Aug 2021
Hello,
I come to you because I have a problem to import a .txt. In fact, I have some .txt files following the same format, namely : 30 lines of headers, and then a format like that :
D; Q; valQ; Ptot; Fsol; ETP; Temp; Vent; Humi; DLI; SSI; IHGR; SWI;
19580801; -99; -; 0.0; 0.00; 4.0; 19.9; 2.3; 10.; 2827.9; 2495.2; -0.999; 0.435;
I tried different function (dlmread, textscan, ...) but I have a problem with the third column because it's not an integer. I'm not interested by these column. So, I would like to have a matrix in Matlab, from the .txt, without the third column. Do you know how to help me ? Thanks !
  1 Comment
per isakson
per isakson on 19 Mar 2016
Edited: per isakson on 19 Mar 2016
Try something like
cac = textscan( fid, '%f%f%*s%f%f%f%f%ff%f%f%f', 'Headerlines',30+1 ...
'Delimiter',';', 'CollectOutput',true )
and study the documentation of textscan

Answers (2)

dpb
dpb on 19 Mar 2016
Edited: dpb on 20 Mar 2016
Looks like an extra count for 'headerlines', maybe? 'Pends on whether the above line is the 30th or the previous 30 were some other text and then the variable names...
I'd only point out here's a place where the use of repmat to count repeat fields is handy rather than trying to count how many '%f' fields one has typed in...
fmt=['%f%f*%f' repmat('%f',1,10)];
cac = cell2mat(textscan(fid,fmt, 'Headerlines',30+1 ...
'Delimiter',';', 'CollectOutput',true ));
Also cell2mat wrapped around textscan gets the double array directly instead of a cell array which is more pain to dereference when not needed.
  2 Comments
Walter Roberson
Walter Roberson on 19 Mar 2016
I think you meant textscan not testscan
dpb
dpb on 20 Mar 2016
Ayup...corrected typo...

Thomas DENIS
Thomas DENIS on 20 Mar 2016
Allright, thanks you a lot both of you ! I managed to do it by using :
fid = fopen('abc.txt');
fmt=['%f%f%*s' repmat('%f',1,10)];
C = textscan(fid,fmt,'Headerlines',30,'Delimiter',';');
Deb = cell2mat(C(:,:));
fclose(fid);
Thanks you !
  1 Comment
dpb
dpb on 20 Mar 2016
What's the point of not simply wrapping textscan with cell2mat directly instead of the temporary C? Use the 'collectoutput' named parameter to collect like terms, too...

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