pdepe daeic12 (line 77) eror

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);

Answer 1

[Bill Greene]

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

Bill