N = 180
L = 2π
M = 0
\mu = 10^{-2}
c_0 = 0
\beta \equiv 1
\beta(x) = 1.01 + (x - 1)^2 (x + 1)^2
\beta(x) = 1.2 + (x - 1)^2 (x + 1)^2 + x
(c_0 > 0
c_0 = 0.1
c_0 = 1
c_0 = 10
