X and Y must be same length, however they already are?

So I am trying to run the following code:

x = [];
y = [];


fid = fopen('HWPlotting.dat');
if fid == -1
    disp('Error:Cannot open file')
else
    total = 0;
    
    while ~feof(fid)
        str = fgetl(fid);
        str = str(3:end);
        [xstr, rest] = strtok(str, 'y');
        y = [y, str2double(rest(3:end))];
        total = total + 1;
        
    end
    closeresult = fclose(fid);
    if closeresult == 0
        disp('File closed')
    end
end

area(x,y)
xlabel('x')
ylabel('y')

title([num2str(total),' data points'])

However I get the error two errors:

"Error using area (line 52)

X must be same length as Y.

Error in HWPlotting (line 25)

area(x,y)"

The .DAT file I use is simple, it's like this and nothing else:

x 0 y 1.1
x 1.3 y 2.2
x 2.2 y 6
x 3.4 y 7.4

So what's really going on? What in this code is not the same length?

[Daniel M]

x = []; % here's your problem

Answer 1

[Walter Roberson]

You do not store any x values, so it is [] after the reading loop.

[Deniz Mert Yayla]

I introduced

x = [str str2double(xstr)]; 

to assign a value to x after the file is read, however it asks me to "Must supply Y data or X and Y data as first argument(s).". How can it make it so that the values are just directly read from the .DAT?

[Walter Roberson]

Needs to be

        x = [x str2double(xstr)]; 

[Deniz Mert Yayla]

Oh.. You are right. Thank you!