For loop iteration through .txt files - matlab

Question

I have a function that is part of an object that I have name TestData. Here are the properties and its constructor:
classdef TestData
properties
metaData = []; % stores meta data in Nx2 array
data = []; % stores data in PxQ array
colLabels = []; % labels columns
colUnits = []; % provides units
temp = []; % temporary to bypass setters while structuring data
end
methods
%% Constructor
function this = TestData(varargin) % Will take in a variable number of inputs
if (nargin == 0)
return;
end
if (nargin == 1 && ischar(varargin{1})) % Case of the input being a file (.txt, .s*p, etc..)
this = readDataFromFile(this, varargin{1});
return;
elseif (nargin == 4) % Case of the input being raw data. Note that the order matters.
this.metaData = varargin{1};
this.colLabels = varargin{2};
this.colUnits = varargin{3};
this.data = varargin{4};
return
else
error('Not enough input arguments.');
end
end
Now, let us say that I have 42 text files that I want to pass into the object. I have created a function for this called extractData that sifts through the data and finds a user input x-axis and y-axis. It does so by first calling a function readDataFromFile, which sets the property arrays that are outlined in the code above. It is a fairly long function and I won't include it for the time being, but I will say that I do know it is working.
The problem: I make an object of the class called myTestData and perform this operation in the CW, myTestData=myTestData.extractData('Tip Type','Tip S/N'). This will look for the Tip Type and Tip S/N. As you can see in the code, the type and S/N are in column 3 of the matrix. If the string is found, it takes the row it was found on, accesses column 3 of that row, and places that value into the temp array. In my case, the type is passive and the S/N is AM66191. It will write this to the temp array, but then on the second iteration of the for loop it will write something else over the first row and the passive and AM66191 will be displayed on the second row. It will do this all the way until the end, where on row 42 I will see the type and S/N, but all the other rows are just garbage. I have attached an image of what the temp array looks like after the second iteration of the for loop. Here is the code for the extractData function:
function this = extractData(this, xAxis, yAxis)
s = dir('*.txt'); % Gather all text files
disp(length(s))
for i=1:length(s) % Loop through and gather data until last element of strcuct
j = 1;
fid = s(i).name; % Open file in read-only mode
this = this.readDataFromFile(fid);
disp(fid)
x = this.metaData(find(contains(this.metaData(:,1), xAxis)),3);
this.temp(i,j) = x;
disp(this.temp(i,j))
j = j+1;
y = this.metaData(find(contains(this.metaData, yAxis)),3); %#ok<*FNDSB>
this.temp(i,j) = y;
disp(this.temp(i,j))
end %for
end %extractData