MATLAB Answers

How to read only some columns of a text file?

4 views (last 30 days)
Samuele Bolotta
Samuele Bolotta on 11 May 2020
Commented: per isakson on 11 May 2020
I'd like to read out only columns from 3 to 7. However, this is not working. Can you help?
Thanks!
%Get events from text file
prompt_totalfiles = 'Enter number of files you want to input: '; %asks for number of files
total_files = input(prompt_totalfiles);
fileids = cell(total_files,1);
j = 1;
Baseline_adjustment = 0.1; %put in baseline photodetector value here (the readout with the led on but the patch cable in pitch black
wholedff = cell(1, 11);
for file = 1:total_files
[inputfile,path] = uigetfile('*.txt');
fileids{file} = fopen(fullfile(path, inputfile));
if fileids{file} == -1
error('Failed to open file "%s"', fullfile(path, inputfile));
end
b = textscan(fileids{file},'%*n %*n %n %n %n %n %n', 'delimiter', '/t');
num = b{3};
epochn = b{4};
state = b{5};
count = b{6};
duration = b{7};
  1 Comment
Walter Roberson
Walter Roberson on 11 May 2020
'delimiter', '\t'
Also if columns 1 and 2 might not be numeric then use %*s for them.

Sign in to comment.

Answers (1)

per isakson
per isakson on 11 May 2020
Edited: per isakson on 11 May 2020
The text file might have more than 7 coloums.
Replace
'%*n %*n %n %n %n %n %n'
by
'%*s%*s%n%n%n%n%n%*[^\n]'
%*[^\n]' skips to the end of line
The code doesn't include end to close the for-loop.
The result of the import might be overwritten for each iteration of the loop.
  8 Comments
per isakson
per isakson on 11 May 2020
" [...] I should use %2s instead of %s." No, the problem is rather with the delimiter. I assume there is no '\t' after the six coloumn.

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!