Hi, I have a set of ODEs that I've evaluated using NDSolve, none of the variables can go below zero and my x' is, how can I state this?
sys = {x[0] == 0.0001, y[0] == .00000000000000000144, z[0] == 0,
w[0] == 0, eq1, eq2, eq3, eq4} /. {p[1] -> 1.2, p[2] -> 1.19,
p[3] -> .016, p[4] -> 19, p[5] -> .05};
sol = NDSolve[sys, {x[t], y[t], z[t], w[t]}, {t, 0, 200}]
I've tried WhenEvent and some variations of boundary conditions so far. When x = 0 I'd like it to stay at zero.
Thanks for any help.
