Can anyone please correct this code for me?

Hi,

I am trying to extract data from a sequence of files. I also need to extract the value of x that corresponds to peak y value from each plot. I have tried the following code but I can't get results. I would be grateful if someone can check it for me. I have attached herewith the files for your kind reference.

close all; clear all; clc;
folder = cd;
for k = 1:2;
    for j = 1:2;
        matFilenameA = sprintf('X%d.out', k);
        matData1     = load(fullfile(cd, matFilenameA));
        %
        matFilenameB = sprintf('Y%d.out', j);
        matData2     = load(fullfile(cd, matFilenameB));
        x = matFilenameA(:,2);
        y = matFilenameB(:,2);
        [maxvaly,idx] = max(y) ;
        maxvalx = x(idx);
        fid=fclose('all');
    end
end

[Birdman]

In which part of code do you have trouble?

[Ismail Qeshta]

First, the loop only calculates one set. Second, I think the following part has a problem.

Thank you.

x= matFilenameA(:,2);
  y= matFilenameB(:,2);
  [maxvaly,idx] = max(y) ;
  maxvalx = x(idx);
  fid=fclose('all');
      end
  end

[Birdman]

You do not assign numerical arrays to x and y. I think you should write

    x= matData1(:,2);
    y= matData2(:,2);

[Ismail Qeshta]

Thanks. I have tried it, but the it still shows the following error message:

Index exceeds matrix dimensions.

Error in Try2 (line 14)
maxvalx = x(idx);

Answer 1

[KSSV]

files = dir('*.txt') ;
N = length(files) ;
iwant = zeros(N,2) ;
for i = 1:N
    data = importdata(files(i).name) ;
    [val,idx] = max(data(:,2)) ;
    iwant(i,:) = [data(idx,1),val] ;
end

Copy all the text file sin one folder and runt his code.

[Ismail Qeshta]

Thanks KSSV. I actually need to plot Y values against X. Your code does not do that.

[KSSV]

files = dir('*.txt') ;
N = length(files) ;
figure
hold on
for i = 1:N
    data = importdata(files(i).name) ;
    plot(data(:,1),data(:,2))
end

[Ismail Qeshta]

Thanks KSSV. Can we extract the value of X that corresponds to the maximum value of y? I need to keep the loop running and extracting the values for all N sets.

[KSSV]

That's what the first code does.....you asked the same question yesterday....without reading your question I answered that.

[Ismail Qeshta]

Thank you KSSV for your great help yesterday and today. Yes, I actually could get the the code yesterday work for only one set of data. But I still have confusion about how to get it worked in a loop.