find number of columns on text file
11 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Is it possible to determine the number of columns in a text file prior to importing the data into matlab?
I can determine the number of rows as follows:
fid = fopen('myFile.txt','rt');
nLines = 0;
while (fgets(fid) ~= -1),
nLines = nLines+1;
end
fclose(fid);
However, is there a way of returning the number of columns? Some of the text files that I need to import contain several column and others contain only one column therefore I require the number of columns in a specific text file in order to use textscan. Note I cannot use importdata or dlmread as some of the files contain nans.
Amended: Consider I create two text files:
d1 = 1+(30-1).*rand(365,3);
d2 = 1+(30-1).*rand(365,1);
mkdir('C:\Matlab_Q');
filename = 'C:\Matlab_Q\ex1.txt';
fid = fopen(filename,'wt');
fprintf(fid,'%f\n',d2);
fclose(fid);
filename = 'C:\Matlab_Q\ex2.txt';
fid = fopen(filename,'wt');
fprintf(fid,'%f\t%f\t%f\n',d1');
fclose(fid);
I now wish to read the number of columns in each text file:
FNames = {'ex1','ex2'};
delimiter = '\t';
for i = 1:length(FNames);
fid = fopen(fullfile('C:\Matlab_Q',[FNames{i} '.txt']),'rt');
tLines = fgets(fid);
numCols{i} = numel(strfind(tLines,delimiter)) + 1;
fclose(fid);
end
This solution returns 1 where it should return 1 and 3. How can this be solved?
0 commentaires
Réponse acceptée
José-Luis
le 20 Nov 2012
Modifié(e) : José-Luis
le 20 Nov 2012
delimiter = ' '; %or whatever
fid = fopen('myFile.txt','rt');
tLines = fgets(fid);
numCols = numel(strfind(tLines,delimiter)) + 1;
fclose(fid);
3 commentaires
Mitchell Thayer
le 7 Jan 2013
Snagged that piece of code for use in a parsing function. Thanks!
-:- Mitchell
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Text Files dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!