Fix the error in code.

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 个评论

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 2016-6-24
编辑:John D'Errico 2016-6-24
Please, stop adding answers every time you want to add information. I've moved your comments into comments, where they belong.
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...
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.
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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回答(1 个)

Cute Doll
Cute Doll 2016-6-24

0 个投票

@David Sanchez @Walter Roberson

1 个评论

I am relatively sure that my username is not an Answer to questions about DAE.

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