Question about a function

I am not sure what is wrong with my function coding, I tried code in the matlab, it works, however the matlab grader says run without outputs, and bring me back the inccorect solution as Variable T has an incorrect value.

Here is the coding I've typed below

function [T,aliveFlag] = tutorial3(T1,timeend,nt)
% Description: This file implements the Fourier Series solution to the heat equation.
%
% Input parameters:
% - T1        - temperature at r=0
% - timeend   - time of simulation in seconds
% - nt        - number of points in time vector
%
% Output parameters:
% - T         - temperature profile along persons head
% - aliveFlag - 1 if person is alive, 0 if the person is dead
    % Spatial (r) parameters
    L      = 0.12;                      % Size of the domain
    rstart = 0;                         % Start of computational domain (m)
    rend   = L;                         % End of computational domain (m)
    nr     = 101;                       % Number of grid points along the radius vector
    dr     = (rend-rstart)/(nr-1);                        % Spatial step size, delta r (m)
    r      = rstart:dr:rend;                        % Vector of grid points in r
    
    % Temporal (t) parameters 
    timestart = 0;                      % Starting time (0 seconds)
    dt        = (timeend-timestart)/(nt-1);                     % Temporal step size, delta t (s)
    time      = timestart:dt:timeend;                     % Vector of times craete this vector
    
    % Phyiscal parameters
                          % Temperature at r=0
    T2    = 37;                         % Temperature at r=L
    A     = T2-T1;                      % Amplitude of the saw tooth wave
    k     = 0.527;                      % Thermal conductivity (W/m-K)
    rho   = 1000;                       % Density (kg/m^3)
    gamma = 3600;                       % Heat capacity (J/kg-K) sigma in this notes
    c     = sqrt(k/(rho*gamma));                         % Heat equation constant                 
    
    
    % Calculate B coefficients using a for loop
    nfs = 1000;               % Number of fourier terms               
    B = zeros(1,nfs);         % Initialise B vector   
    lambda=zeros(1,nfs);      % Initialise lambda vector
    for n = 1:nfs           
        B(n)=2*A/(n*pi);                   % Calculate B coefficients
        lambda(n)=(n*pi*c)/L;
    end
    % above loop is givinga vector of Fourie coefficient
    
    %% Solve for T using three for loops in time, space, and Fourier series
    
    % Loop through time
    for i = 1:nt               % For each time
        
        t = time(i);           % time in seconds
        
        % Vector of zeros to initialise the Fourier series solution.
        % This should be re-initialised at each new time step.
        T = zeros(1,nr); 
        
        % Loop through space
        for j = 1:nr          % For each grid point        
            T(j) = 78*r(j)/L - 41;         % Add the steady state solution
            
            % Loop through the Fourier series
            for n = 1:nfs
                T(j)    = T(j) + B(n)*sin(n*pi*r(j)/L)*exp(-lambda(n)^2*t);  % Calculate series sum for T at r(i) and t
            end
        end
    end
    aliveFlag=mean(T)>22;
end

[KALYAN ACHARJYA]

What are the typical values of input arguments T1,timeend,nt?

[Michael Wang]

These are all the input values.

[Michael Wang]

T1 = -41;
timeend = 60;
nt      = 101;
[T,aliveFlag] = tutorial3(T1,timeend,nt);

These are the elements for input values.

Answer 1

[Cris LaPierre]

"Code ran without output" is just a message to let you know your code has finished running and did not produce any outputs. Without the messgae, it might be difficult to recognize when the code has finished executing. If you want to see outputs, leave a semicolon off one of your lines. However, this is unnecessary and potentially undesirable.

If you are not passing the assessments, that means there is an error in your solution to the problem. Here, it appears you are not correctly computing the values for T.

[Walter Roberson]

It looks strange to me to start the fourier output with the value of the steady-state solution ? Is that intended to correspond to n = 0 ?