Fix the error in code.

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Cute Doll 2016-6-24

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https://ww2.mathworks.cn/matlabcentral/answers/292199-fix-the-error-in-code

评论： Bill Greene 2016-6-24

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
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John D'Errico 2016-6-24

Plottt.png

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 2016-6-24

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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