• Support PF! Buy your school textbooks, materials and every day products Here!

Matlab cannot Produce graph

  • Thread starter iwan89
  • Start date
  • #1
27
0

Homework Statement


Hello there. I ran a matlab program and i cant produce any graph. Please help me


Homework Equations


This are the program


L = 1.;
T = 1.;
maxk = 2500;
dt = T/maxk;
n=50;
dx = L/n;
cond = 1/4;
b = 2.*cond*dt/(dx*dx);
for i= 1:n+1
x(i) = (i-1)*dx;
U(i,1) = sin(pi*x(i));
end
for k=1:maxk+1
u(1,k) = 0.;
u(n+1,k)=0.;
time(k) = (k-1)*dt;
end
for k=1:maxk
for i=2:n;
u(i,k+1)=u(i,k)+0.5*b*(u(i-1,k)+u(i+1,k)-2.*u(i,k));
end
end
figure (1)
plot (x,u(:,1),'-',x,u(:,100),'-',x,u(:,300),'-',x,u(:,600),'-')
title ('Temperature within the explicit method')
xlabel ('X')
ylabel ('Y')
figure (2)
mesh (x,time,u')
title ('Temperature within the explicit method')
xlabel ('X')
ylabel ('Temperature')


The Attempt at a Solution


The program works but i cant produce any graph. I think there are little mistake somewhere.. :( pls help me
 

Answers and Replies

  • #2
Office_Shredder
Staff Emeritus
Science Advisor
Gold Member
3,750
99
I think your problem is this line here

U(i,1) = sin(pi*x(i));
which should have a u(i,1) instead of a U(i,1)
 
  • Like
Likes 1 person
  • #3
27
0
Thank you so much :) really appreciate it :)
1 more thing
how can i tabulate data from the graph?
 
  • #4
Office_Shredder
Staff Emeritus
Science Advisor
Gold Member
3,750
99
I don't really understand your question (are you asking how to use the tabulate function in matlab?). At any rate you should make a new thread if you have a new question.
 
  • #5
27
0
ok :) i will post a new question
 

Related Threads on Matlab cannot Produce graph

Replies
1
Views
581
  • Last Post
Replies
4
Views
814
Replies
3
Views
556
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
16
Views
2K
Replies
18
Views
1K
Replies
11
Views
485
Replies
4
Views
2K
Replies
1
Views
1K
Top