Zeros of the Bessel J and Y functions and their derivatives
This package provides functions to compute the zeros of the J and Y functions, and the zeros of their derivatives, where J and Y are Bessel functions of the first and second kind, respectively.
For all functions described below, the order nu::Real
is a finite number and n::Integer
is a
positive integer. When nu isa AbstractFloat
, the returned value has the same type as nu
. When
nu isa Integer
, the usual promotion rules apply, so that for most builtin integer types the output
type will be Float64
. However, when nu isa BigInt
the output type will be BigFloat
.
When the output type is Float64
, the exported functions (besselj_zero
, bessely_zero
,
besselj_deriv_zero
, and bessely_deriv_zero
) will use lookup tables to rapidly return function
zeros if the order nu
is one of the first few values of 0, 1, ...
and the enumerator n
is one
of the first values of 1, 2, 3, ...
. See the individual function docstrings for the actual
extents of the lookup tables.
besselj_zero(nu, n)
Return the n
th zero of the Bessel J function of order nu
.
bessely_zero(nu, n)
Return the n
th zero of the Bessel Y function of order nu
.
besselj_deriv_zero(nu, n)
Return the n
th nonvanishing zero of the derivative of the Bessel J function of order nu
.
bessely_deriv_zero(nu, n)
Return the n
th zero of the derivative of the Bessel Y function of order nu
.
FunctionZeros.besselj_zero_asymptotic(nu, n)
Asymptotic formula for the n
th zero for the Bessel J function of order nu
.
FunctionZeros.bessely_zero_asymptotic(nu, n)
Asymptotic formula for the n
th zero for the Bessel Y function of order nu
.
FunctionZeros.besselj_deriv_zero_asymptotic(nu, n)
Asymptotic formula for the n
th nonvanishing zero of the derivative of the Bessel J function of order nu
.
FunctionZeros.bessely_deriv_zero_asymptotic(nu, n)
Asymptotic formula for the n
th zero of the derivative of the Bessel Y function of order nu
.