// BesselJ returns Jn(x)
func BesselJ(n int, x float64) float64 {
var y C.double
switch n {
case 0:
y = C.gsl_sf_bessel_J0(C.double(x))
case 1:
y = C.gsl_sf_bessel_J1(C.double(x))
default:
y = C.gsl_sf_bessel_Jn(C.int(n), C.double(x))
}
return float64(y)
}
func J1(x float64) float64 {
return float64(C.gsl_sf_bessel_J1(C.double(x)))
}