Heated-Rod Equation Recursive Question

investigating the heat rod function.

Length = 50 cm uniform intiial temperature u0 = 100dC and thermal diffusivity k = 0.15. I was given the following code in the text, and it is fine until I put x into the sine term.

it says my error is in line 8. I know it is the x.

How can I get the correct input arguements? Also how would I get the graphs of u(x, 30) abd u(25,t)?

Answer 1

[Shadaab Siddiqie]

It looks like you want to create function in a file and run it. Refere Create function in files for more information. Here is the code

function u = expand(x,t)
k = .15;
L = 50;
u0 = 100;
S = 0;
N= 50;
for n = 1:2:2*N+1
     S = S + 1/n*exp((-n^2)*(pi^2)*k*t/(L^2))*sin((n*pi*x)/L); 
end
u=(4*u0*S)/pi;
end

To plot you can run

a1 = expand(1:30,30); 
a2 = expand(25,1:30); 
plot(a1);
plot(a2);

from the command line or from another file.