correct the following code for unsteady maxwell nanofluids

%f"'+ff"-f'^2+lamda(g+Nh)-Mf'-delta(f'+(eta/2)*f")=0
%g"-Prfg'+PrNb(g'h'+Nt/Nb*g^2)-delta((eta/2)f')Pr+PrEc*f"=0
%h'+Scfh'+Nt/Nbg"-gamma*h+(f-(epsilon*eta/2)h')=0

%f(0)=s,f'(0)=1, g'(0)=-gamma(1-g(0)), h(0)=1; f'(infinity)=0,
%g(infinity)=0, h(infinity)=0
function sol= sample2
global B;
B=4;
global s;
s=0;
solinit1=bvpinit(linspace(0,B,100),@sample1init);
sol=bvp5c(@sample1ode,@sample1bc,solinit1);
figure(1);
plot(sol.x,sol.y(1,:),'g.-');
hold on;
plot(sol.x,sol.y(3,:),'b.-');
hold on;
plot(sol.x,-sol.y(5,:)),'r.-';
xlabel('\eta');
ylabel('F(\eta),G(\eta),-H(\eta)');
legend('F(\eta)','G(\eta)','-H(\eta)')
hold off;
end

function dydx=sample1ode(x,y)
dydx=[ % f=y(1);f'=y(2), f"=y(3), f"'=y(4)
 y(4)+y(1)y(3)-y(2)*y(2)-delta(y(2)+1/2(eta*y(3))-epsion(y(1)*y(1)*y(4)-2*y(1)*y(2)*y(3))-beta*y(2)+lamda(y(5)+N*y(8))-M*y(2)=0) 
 % g=y(5) g'=y(6), g"=y(7)
 y(7)-Pr*(y(1)*y(2))-delta*Pr*((eta/2)*y(2)+Pr*Nb*(y(6)*y(9)+(Nt/Nb)*y(5)*y(5))+Pr*Ec*y(3)=0
  % h=y(8)
 y(9)+Sc*y(1)*y(9)+(Nt/Nb)*y(7)+(y(1)-epsilon*(eta/2)*y(9)
 ];
end
function res=sample1bc(ya,yb)
 res=[ya(1)-s  %f(0)=s
 ya(2)-1       %f'(0)=1
 yb(2)-1       %f'(inf)=1
 yb(5)      %  g(inf)=0
 ya(6)+gamma(1-y(5))       %  g'(0)=-gamma(1-y(5))
 ya(8)+1        % h(0)=-1
 yb(8)          %h(inf)=0     
 ];
end
function v=sample1init(x)
global s;
g=s;
v=[ 0 % f(0)
 g % f'(0)
 1 % g(0)
 g % g'(0)
 0 % h(0)
 ];
end

I am getting the following error, Can anyone help

sample3

File: sample3.mlx Line: 27 Column: 11

Invalid expression. Check for missing multiplication operator, missing or unbalanced delimiters, or other syntax error. To construct matrices, use brackets instead of parentheses.

Answer 1

[Torsten]

dydx has to consist of 6 equations:

dydx(1) = y(2), dydx(2) = y(3), dydx(3) = f'''

dydx(4) = y(5), dydx(5) = g''

dydx(6) = h'

Thus you also need 6 boundary conditions and 6 initial conditions.

And don't forget multiplication signs in your expressions, e.g.

y(4)+y(1)<here>y(3)-y(2)*y(2)-delta<here>(y(2)+1/2(eta*y(3))-epsion<here>(y(1)*y(1)*y(4)-2*y(1)*y(2)*y(3))-beta*y(2)+lamda<here>(y(5)+N*y(8))-M*y(2)