I am trying to solve equation
%%%%u(∂u/∂t)=∂^2u/∂z^2
% Bc's
%%%%C(z,0) =0, z>0; ∂u(0,t)/∂z =-b, t>0; C(1,t) = 0, t>0;
I have attached the code and resulting figure. CAn some body fix this issue.
function pdex11
m=0;
x = linspace(0,1,100)
t = linspace(0,1,33)
sol = pdepe(m,@pdex1pde,@pdex1ic,@pdex1bc,x,t);
% Extract the first solution component as u.
u = sol(:,:,1)
surf(x,t,u)
title('Numerical solution.')
xlabel('Distance x')
ylabel('Time t')
% A solution profile can also be illuminating.
figure
plot(x,u(end,:))
title('Solution at t = 2')
xlabel('Distance x')
ylabel('u(x,2)')
function u0 = pdex1ic(x)
%u0 = 1;
% --------------------------------------------------------------
u0 = 0;
function [pl,ql,pr,qr] = pdex1bc(xl,ul,xr,ur,t)
% pl = u1;
% ql = 0;
% pr = 1;
% qr = 1;
pl = -1;
ql = 1;
pr = ur;
qr = 0;
function [c,f,s] = pdex1pde(x,t,u,DuDx)
% c = 1;
% f = (1/u)*DuDx;
% s = 0;
c = u;
f = DuDx;
s = 0;

5 Kommentare

Stephen23
Stephen23 am 24 Jun. 2016
What is the error? If you actually tell us what the code is doing wrong then we can help you to fix it. otherwise we have to use our mind reading powers, which are not always so reliable.
John D'Errico
John D'Errico am 24 Jun. 2016
Bearbeitet: John D'Errico am 24 Jun. 2016
Please, stop adding answers every time you want to add information. I've moved your comments into comments, where they belong.
John D'Errico
John D'Errico am 24 Jun. 2016
Bearbeitet: John D'Errico am 24 Jun. 2016
Moved to a comment (from Cute Doll):
1st error This DAE appears to be of index greater than 1.
2nd error [y,yp,f0,dfdy,nFE,nPD,Jfac] = daeic12(odeFcn,odeArgs,t,ICtype,Mt,y,yp0,f0...
John D'Errico
John D'Errico am 24 Jun. 2016
Moved to a comment:
I am trying to solve equation u(∂u/∂t)=∂^2u/∂z^2 Bc's C(z,0) =0, z>0; ∂u(0,t)/∂z =-b, t>0; C(1,t) = 0, t>0;
output is show in attached figure.
Bill Greene
Bill Greene am 24 Jun. 2016
You submitted this same question to the MATLAB newsgroup using the user name "kanwal shahzadi" and received an answer that correctly identified the problem with your code. What is your purpose in making up a new fictitious user name and posting the question again here in MATLAB Answers?

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Antworten (1)

Cute Doll
Cute Doll am 24 Jun. 2016

0 Stimmen

@David Sanchez @Walter Roberson

1 Kommentar

Walter Roberson
Walter Roberson am 24 Jun. 2016
I am relatively sure that my username is not an Answer to questions about DAE.

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Gefragt:

am 24 Jun. 2016

Kommentiert:

am 24 Jun. 2016

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