Error Index in position 1 exceeds array bounds (must not exceed 4).

I am trying to run a "for loop" for a list of numbers. I am getting the correct answers except for my last number "1.5". Here is what my error is saying:

Index in position 1 exceeds array bounds (must not exceed 4).

Error in WaveEquation (line 30)

Here is my Code:

clear all; format compact; tic
delx = 0.1;
u = 1;
r= [0.2, 0.5, 0.8, 1, 1.25, 1.5];
% r=1;
j=1;

for i = r
    delt = i.^2*delx./u;         % Delta Time Step Size
    Tsteps = round(1./delt);     % Number of Steps
    x1 = zeros(Tsteps, 1./(2*delx)+2);

    % Initial Conditions
    x = 0:delx:.5+delx;
    x1(1,:) = sin(pi*x);
 
    % Boundary Conditions
    x1(2,2:end-1) = .5*(x1(1,1:end-2)+x1(1,3:end));
    x1(2,end) = x1(2,end-2);                                              % Reflection Line
    for row = 3:size(x1,1)
       for col = 2:size(x1,2)-1
           x1(row,col) = 2*(1-i)*x1(row, col)+i*(x1(row-1,col-1)+x1(row-1,col+1))-x1(row-2,col);
       end
       x1(row,end) = x1(row,end-2);                                      % Reflection Line
    end
    x2 = [x1,fliplr(x1(:,1:end-3))];
    fprintf('\nr =%f', i);

    if (delx==.1)
        dispmat = x1(1:6,1:7);
        fprintf('\nExplicit Method\n')
        disp(num2str(dispmat))
    end
    j=j+1;
end

And here is my Command Window. I am getting what I need up until r = 1.5.

Answer 1

[KALYAN ACHARJYA]

Here, x1 if you check carefully

>> whos x1
  Name      Size            Bytes  Class     Attributes
  x1        4x7               224  double              

x1 size is 4x7 (It has 4 rows, 7 columns), but you are trying to access rows from 1 to 6

  dispmat = x1(1:6,1:7);
  %.............^row,^columns range

Modify the code accordingly