MATLAB: How to write matlab bvp4c code for moving boundary surface problem

bvp4c multiple graph for different value of 'r'

hello, I am new in the bvp4c method of Matlab. I want to find multiple graphs for different value of 'r' for the following problem. Equation is f''' +ff''=0 Boundary condition is f(0)=0, f'(0)=1-r, f'(infnty)=r

Best Answer

Hi,

i recommend to start simple and work step by step:

Have a read in the documentation of bvp4c
Try to implement your model with a single fixed value for r and get a valid solution
Once you have this, use a for loop to vary r like needed for your purposes and save all the results in a Matrix in different columns or rows
Plot the results by using the saved values

Problems by doing this? --> Come back and ask a specific question including your code so far.

Best regards

Stephan

Related Solutions

MATLAB: Solving a boundary value problem using bvp4c

    function res = bcfun(yl,yr)
        res = zeros(5,1);
        res(1) = yl(1);
        res(2) = yl(2);
        res(3) = yr(2)-1;
        res(4) = yl(4)-1;
        res(5) = yr(4);
    end

Best wishes

Torsten.

MATLAB: Help regarding use of BVP4C in solving an third order ODE.

Hi,

this works:

init=bvpinit(linspace(0,4,8),[0 0 0]);
sol=bvp4c(@rhs_bvp,@bc_bvp,init);
plot(sol.x,sol.y(1,:),sol.x,sol.y(2,:),sol.x,sol.y(3,:))
function bc=bc_bvp(yl,yr) %ya(1), ya(2), yb(2)
bc=[yl(1); yl(2); yr(2)-1];
end
function rhs=rhs_bvp(x,y)
rhs=[y(2); y(3); y(2)-y(1)*y(3)-1];
end