I was given these set of differential eqs. dy(1)=y(2), dy(2)=y(3), dy(3)=y(4), dy(4) =-w/(E*I), with boundary conditions: y1(0)=0, y3(0)=0, y1(L)=0, y3(L)=0. I have to use bvp4c to solve it but I can't do it here is my code. What am I doing wrong?

function dy=odefun(x,y)
w=100;
E=29000000;
I=285;
dy=[y(2); y(3); y(4); -w/(E*I)]

function res=bcfun(y0,yL)
res=[y0(1); y0(3); yL(1); yL(3)]

solinit=bvpinit(linspace(0,100,100),[1 0]);
sol=bvp4c(@odefun, @bcfun, solinit);

[Walter Roberson]

What are y0 and y3 ? They do not seem to occur in the first part.