Help me to set this code?
Show older comments
hi I want to get one specific error value for some specific parameter change. I'm unable to extract specific value of error.
nk
function nk
a=0.1;
mu=0.0;
r=2.0;
Ec=0.3;
Nr=10;
solinit= bvpinit(linspace(a,100,1000),[0 0 0 0 0]);
% Set the options with the desired RelTol value
relTol = 1e-4;
AbsTol=1e-6;
options1 = bvpset('RelTol', relTol,'AbsTol',AbsTol);
sol = bvp5c(@Needleode,@Needlebc,solinit,options1);
eta = sol.x; % mesh points
f = sol.y; % solution values at the mesh points
plot(eta,f(1,:))
% Calculate the maximum error
exact_solution=1e-4;
E=max(abs(f - exact_solution));
%disp(E)
% Calculate the number of mesh points
num_meshpoints = length(eta);
%disp(num_meshpoints)
end
function dfdeta = Needleode(eta,f)
Pr=6.8;
Ec=0.3;
mu=0.0;
k=0.0;
Nr=10;
r=3.0;
t1=1+mu*f(4);
t2=1+k*f(4);
u=f(4)*(r-1)+1;
v=eta*(t2+(4/(3*Nr))*(u)^3);
ff1=-(1/(2*eta))*((1/t1)*-2*eta*mu*f(3)*f(5)+t1*f(1)*f(3)+2*f(3));
k_1=f(5)*t2+k*eta*(f(5)^2);
k_2=(1/2)*Pr*f(1)*f(5)+(1/t1)*4*Pr*Ec*f(3)^2;
k_3=(2/(3*Nr))*f(5)*(u^3);
k_4=(4/Nr)*(u^2)*eta*(f(5)^2)*(r-1);
ff2=-(1/(v)*(k_1+k_2+k_3+k_4));
dfdeta=[f(2);f(3);ff1;f(5);ff2];
end
function res = Needlebc(f0,finf)
a=0.1;e=1e-2;
res = [f0(1)-(a*e/2)
f0(2)-e/2
finf(2)-(1-e)/2
f0(4)-1
finf(4)-0
];
end
This is the code .
second i give the the exact solution value myself. How to calculate it manually?
1 Comment
Torsten
on 16 May 2023
I don't understand what you try to do and what you are asking for.
Answers (0)
Categories
Find more on Boundary Value Problems in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!