# pdepe daeic12 (line 77) eror

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Max on 22 Apr 2014
Answered: Bill Greene on 27 Apr 2014
Hello.
I'm trying to solve a partial differential equation of the type that can be solved with pdepe, but it eror. Help please
So in general: There is a piece of land which receives contaminants. plot only limited depth. C1 C2 C3 - varying the intensity of the absorption of contaminants At the picture I wrote out main conditions of distribution.
At the initial time there is no soil pollutants.
function Dif_test
m=0;
x = linspace(0,0.1,10);
t = linspace(0,5,30);
sol=pdepe(m,@pdex6pde,@pdex6ic,@pdex6bc,x,t);
u1=sol(:,:,1);
u2=sol(:,:,2);
u3=sol(:,:,3);
figure
surf(x,t,u1)
title('u1(x,t)')
xlabel('Distance x')
ylabel('Time t')
figure
surf(x,t,u2)
title('u2(x,t)')
xlabel('Distance x')
ylabel('Time t')
figure
surf(x,t,u3)
title('u3(x,t)')
xlabel('Distance x')
ylabel('Time t')
end
%-------------------------------------------------
function [ pl,ql,pr,qr ] = pdex6bc(xl,ul,xr,ur,t)
cs=1;
a=0.5;
ql=[0; 0; 0];
pl=[ur(1)-a*cs; ul(2)-(1-a)*cs; 0];
qr=[1; 1; 0];
pr=[0; 0; 0];
end
%--------------------------------------------------
function u0 = pdex6ic(x)
u0=[0;0;0];
end
%--------------------------------------------------
function [c,f,s] = pdex6pde(x,t,u,DuDx)
d1=0; d2=0; d=0.1;
a=10; a1=0.001; a2=0.01;
D=[1 d1 0; d2 d 0 ; 0 0 0 ];
K=[-a 1 0; a -(1+a2) a1; 0 a2 -a1];
c=[1;1;0];
s=K*[1;1;0];
f=D * DuDx;
end
%-------------------------------------------------
Error using daeic12 (line 77) This DAE appears to be of index greater than 1.
Error in ode15s (line 311) [y,yp,f0,dfdy,nFE,nPD,Jfac] = daeic12(odeFcn,odeArgs,t,ICtype,Mt,y,yp0,f0,...
Error in pdepe (line 317) [t,y] = ode15s(@pdeodes,t,y0,opts);
Error in Dif_test (line 6) sol=pdepe(m,@pdex6pde,@pdex6ic,@pdex6bc,x,t);
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### Answers (1)

Bill Greene on 27 Apr 2014
I don't see any boundary conditions on c3. I think this may be the cause of your problem.
Bill
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