```Date: Dec 29, 2012 7:21 AM
Author: Christos Mountrichas
Subject: Warning: Input arguments must be scalar.

Hi everyone,I created a script to solve the diffusion equation for a specific situation. However, although i get the right results, I am getting the "Warning: Input arguments must be scalar" message. Please, I would appreciate any help.Here is the code:%clear; clf;         % clean file and clear figure  xmax = 10;         % input length of domain in x direction tmax = 4;          % input end time D = 5.435;         % input diffusion coefficient cb1=0.4; cb2=0;    % input boundary concentrations dx = 1;            % input gap between two x coordinates (x=0,1,2...10) dt = 0.5*dx^2/D;   % input time increment  nx=fix(xmax/dx)+1; % total number of x(i)  mt=fix(tmax/dt)+1; % total number of t(j)  r=D*dt/dx^2; s=1-2*r; t = [0: dt: tmax]; % t(j) x = [0, dx: xmax]; % x(i) c = zeros(1:nx,1); c(1,1)=cb1; c(nx,1)=cb2; % c(i,j) at t=0 % % Generate remaining rows of C for	j = 2: mt    c(1,j)=cb1;	for  i = 2: nx-1		c(i,j) = s*c(i, j-1) + r*(c(i-1,j-1)+c(i+1,j-1));	end;    c(nx,j)=cb2; end;Cx=c';t1=fix(1/dt)+1; t2=fix(2/dt)+1; t3=fix(4/dt)+1;plot(x,c(:,t1),'r-', x,c(:,t2),'b--', x,c(:,t3),'g:'); hold on;xlabel('x(i)'); ylabel('c(i,j)'); hold on
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