plotting with for loop
4 views (last 30 days)
Show older comments
hello I am trying to solve FTCS discretization of the heat equation
and I have writtenn the below code:
I have 3 grid refinement, dx=[0.5,0.25,0.05];
I am going to plot 3 plot get for each grid (x,T1) in one plot. Currently, I can not plot 3 plot in one plot. I do not know how pull out T1 values after completion in for loop. Can someone tell me how to plot?
%setting up the parameters
clear;clc;;close all;
U0=2;
dt=0.01;
tf=1000;
ntotal=tf/dt;
dx=[0.5,0.25,0.05];
Kappa=0.001;
% boundary condition
for i=1:length(dx)
x = (-3:dx(i):3);
n=length (x);
alpha=Kappa*dt./dx(i).^2;
for j=1:n
if (1<x(j)) || (x(j)<-1)
T0(j)=0;
else T0(j)=U0;
end
end
%solving the problem with FTC
for k=1:ntotal
for i=2:n-1
T1(i) = T0(i) + alpha*(T0(i+1)-2*T0(i)+T0(i-1));
T1(1)=T0(1) + alpha*(T0(2)-2*T0(1)+0);
T1(n) = T0(n) + alpha*(0-2*T0(n)+T0(n-1));
end
T0=T1;
end
figure
plot (x,T1)
hold on
end
3 Comments
Accepted Answer
Star Strider
on 28 Sep 2020
To plot all of them on the same axes, put the figure call before the loop instead of inside it:
figure
hold on
for i=1:length(dx)
x = (-3:dx(i):3);
n=length (x);
alpha=Kappa*dt./dx(i).^2;
for j=1:n
if (1<x(j)) || (x(j)<-1)
T0(j)=0;
else T0(j)=U0;
end
end
%solving the problem with FTC
for k=1:ntotal
for i=2:n-1
T1(i) = T0(i) + alpha*(T0(i+1)-2*T0(i)+T0(i-1));
T1(1) = T0(1) + alpha*(T0(2)-2*T0(1)+0);
T1(n) = T0(n) + alpha*(0-2*T0(n)+T0(n-1));
end
T0=T1;
end
plot (x,T1)
end
hold off
legend(compose('dx = %.2f',dx), 'Location','S')
.
0 Comments
More Answers (0)
See Also
Categories
Find more on Crystals in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!