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Wrong graph is coming with this code

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MINATI
MINATI on 7 Aug 2020
Commented: Star Strider on 27 Aug 2020
function main
A=0.5; pr=1; a=1; phi=0.1;rhos=997.1;Cps=4179;ks=0.613;rhof=8933;Cpf=385;kf=401;
a1=(1-phi)^-2.5*((1-phi)+phi*(rhos/rhof)); Knf=(ks+2*kf-2*phi*(kf-ks))/(ks+2*kf+phi*(kf-ks));
a2=((1-phi)+phi*((rhos*Cps)/(rhof*Cpf)))*Knf;
xa = 0;xb = 5;solinit=bvpinit(linspace(xa,xb,101),[0 1 0 a 1 0 0 0]);
sol = bvp4c(@ode,@bc,solinit); x = linspace(xa,xb,101);S = deval(sol,x);
function res = bc(ya,yb)
res = [ya(1); ya(2)-1; ya(4); ya(5)-a; ya(7)-1; yb(2); yb(5); yb(7)];
end
function dydx = ode(~,y)
dydx = [y(2); y(3); 2*a1*y(2)*(y(2)+y(5))-a1*y(3)*(y(1)+y(4));
y(5); y(6); 2*a1*y(5)*(y(2)+y(5))-a1*y(6)*(y(1)+y(4));
y(8); A*pr*a2*y(7)*(y(2)+y(5))-pr*a2*y(8)*(y(1)+y(4))];
end
figure(14)
f1 = @(x,y) S(2);
fsurf(f1)
xlabel '\bfx';ylabel '\bfy';zlabel '\bff^\prime(\eta)'
hold on
end
%% The graph is not obeying Boundary Condition
%% I am trying graphs like Fig. (14) and another is contour (Attached)

Accepted Answer

Star Strider
Star Strider on 26 Aug 2020
Using fsurf is not appropriate here.
Try this instead:
figure(14)
hs = surf(S);
grid on
xlabel '\bfx';ylabel '\bfy';zlabel '\bff^\prime(\eta)'
% shading('interp') % Optional
% hs.EdgeColor = 'none'; % Optional
That produces this plot:
I am not certain what the reference to ‘S(2)’ is suposed to do, beccause ‘S’ is a matrix. This plots the entire matrix.
.
  6 Comments
Star Strider
Star Strider on 27 Aug 2020
Thank you!
Your ccode does not produce the plot in the .PDF file. I have no idea what you are doing.
You can use essentially the same code to create the contour plot as the surf plot. Just call contour instead of surf, and remove the zlabel and view calls.
As always, my pleasure!

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