Hi, I have a problem trying to solve a differentail equation:
neff2a[x_] = Piecewise[{{0.0, x <= zero}, {neff2[x][[2, 1, 2, 1]], zero < x < d}, {0.0, x >= d}}]
where neff2[x] element is a constant value, so it is a step function:
.
I define differential equation:
ps2 = D[D[V2[x], x], x] == neff2a[x]/\[Kappa]
So it is defined like that:
I'm trying to solve the equation:
psres2 = NDSolve[{ps2, V2[0] == 0.0, V2[d] == U}, V2[x], {x, 0.0, d}]
but I get:
NDSolve::bvdisc: NDSolve is not currently able to solve boundary value problems with discrete variables. >>
why? Is there any way to solve this equation by Mathematica?
Thanks in advance, Mariusz