Storing elments of marix from text file into variables

4 vues (au cours des 30 derniers jours)
Mohammad Zaved Siddiqui
Mohammad Zaved Siddiqui le 21 Sep 2015
I'm having one text file containing a matrix in which the first column is a variable lets say x ,first row is a variable lets say y and all the elements inside except x and y are z.How do I read this text file and store them in separate variables .I tried using this but it didn't work.I think I've not stored the elements in z correctly if yes what should I do to correct it?
input = load('matrix.txt');
x= input(:,1)./100; y= input(1,:); z =input(:,:);
end
  2 commentaires
Stephen23
Stephen23 le 21 Sep 2015
Modifié(e) : Stephen23 le 21 Sep 2015
Is that matrix correct? It seems to be missing the first element. Could you confirm if the first row would have four or five elements.
Because of the missing first element there are different ways that this matrix could be read into MATLAB.
Mohammad Zaved Siddiqui
Mohammad Zaved Siddiqui le 21 Sep 2015
Modifié(e) : Mohammad Zaved Siddiqui le 21 Sep 2015
yes it is having four elements only because the first row and first column are variable and other elements are the values at given combination of these two variables

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Réponse acceptée

Jan
Jan le 21 Sep 2015
Modifié(e) : Jan le 21 Sep 2015
This is a bad method to store data, because Matlab must guess the size of the data.
fid = fopen(FileName, 'r');
if fid==-1, error(Cannot open file: %s', FileName); end
FirstLine = fgets(fid);
y = sscanf(FirstLine, '%f');
n = length(y);
M = fscanf(fid, '%f', [n+1, Inf]);
fclose(fid);
x = M(:, 1);
Data = M(:, 2:n+1);
Perhaps you need some transpose operators to get the wanted orientations.
  3 commentaires
Jan
Jan le 22 Sep 2015
If you post the error messages, finding an improvement is easier. I cannot run Matlab during the daytime, so it is possible that the code contains a bug. But you can either fix it by you own or help me finding it. At least this code should contain enough ideas to allow you to solve the problem.
Mohammad Zaved Siddiqui
Mohammad Zaved Siddiqui le 25 Sep 2015
I used the same code and fixed it myself.thanks for the help

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Plus de réponses (1)

Thorsten
Thorsten le 21 Sep 2015
Based on Jan's solution, I wrote the following function that does the job:
function [x y data] = readxydata(filename)
fid = fopen(filename, 'r');
if fid == -1, error('Cannot open file: %s', filename); end
y = sscanf(fgets(fid), '%f');
data = fscanf(fid, '%f', [numel(y)+1, Inf])';
st = fclose(fid);
if st ~= 0, error('Cannot close file: %s', filename); end
x = data(:, 1);
data = data(:, 2:end);
  1 commentaire
Mohammad Zaved Siddiqui
Mohammad Zaved Siddiqui le 25 Sep 2015
Showing error "Error: File: matrix_read_3_var.m Line: 3 Column: 1 Function definitions are not permitted in this context."

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