how to debugg the error : size input must be integers

function u = Section1_4
% This function code is to plot u(x,y) = u1(x,y)+u2(x,y)
% Description: This file is specifically plotting the centre of the domain 
% The analytical solution for the Laplace Equation for section 1.4 
 
%Input parameters 
% C0 = u1(x,y)
% C2 = u2(x,y) 
 
% The following is the spatial parameters 
L = 3/2; %length of the x-dimension (we only want the centre domain) 
H = 1/2; % length of the y-dimension 
T_1 = -5;  % temperature profile 
T_2 = -10; % temperature profile 
nx = 1.5; % Number of grid points x-direction 
ny = 0.5; % Number of grid points in the y direction 
x = linspace(0,L,nx);
y = linspace(0,H,ny);
nfs = 50;
n = 1;
k = ((n*pi)/(L)); 
u =ones(nx,ny);    %% line were the error is 
 
% Analytical solution
for i=1:nx
   for j=1:ny
      for m = 1: nfs
          upper_side = ((16*T_1/((n^3)*(pi)^3)))*(((1-cos(n*pi))/sinh(k*H)))*(sinh(k*y(j)))*(sin(k*x(j)));
          lower_side = ((16*T_2/((n^3)*(pi)^3)))*(((1-cos(n*pi))/sinh(-k*H))).*(sinh(k*y-k*H)).*(sin(k*x(j)));
  % full solution 
 u(i,j) = u(i,j) + upper_side + lower_side;
      end 
   end 
end
contourf(x,y,u');
pcolor(x,y,u');
shading interp;
title('Temperature Value at the Centre of Domain');
xlabel('x');
ylabel('y');
colorbar;
surf(x,y,u');
 
end 

Answer 1

[per isakson]

"how to debug"

Before trying to fix the problem see: Debug a MATLAB Program

Next set Pause on Errors

and run Section_4

>> Section1_4
Error using ones
Size inputs must be integers.
Error in Section1_4 (line 22)
    u =ones(nx,ny);    %% line were the error is 
    

check the values of nx and ny

K>> nx,ny
nx =
          1.5
ny =
          0.5
K>>     

They are not integers, which causes the error, and the next step will be to find out why.