yn

Compute the Bessel function of the second kind, of order n. The input parameter x is a real number greater than 0.

Interface Definition

C interface:

float ynf(int n, float x);

double yn(int n, double x);

Parameters

Parameter	Type	Description	Input/Output
n	For ynf, n is an integer. For yn, n is an integer.	Computing order.	Input
x	For ynf, x is of single-precision floating-point type. For yn, x is of double-precision floating-point type.	Floating-point value of the input data.	Input

Return Value

The result of rSign = ((n & 1) & nSign) * (-1) is returned, where nSign = n > 0?0:1.

If the input x is less than 0, the return value is NaN.
If the input x is 0, the return value is -inf*rSign.
If the input x is inf, the return value is 0.
If the input x is NaN, the return value is NaN.

Dependency

C: "km.h"

Example

C interface:

    printf("yn(1, 0.0) = %.15f\n", yn(1, 0.0));
    printf("yn(2, -0.0) = %.15f\n", yn(2, -0.0));
    printf("yn(3, 1.5) = %.15f\n", yn(3, 1.5));
    printf("yn(4, -2.5) = %.15f\n", yn(4, -2.5));
    printf("yn(5, INFINITY) = %.15f\n", yn(5, INFINITY));
    printf("yn(6, -INFINITY) = %.15f\n", yn(6, -INFINITY));
    printf("yn(7, NAN) = %.15f\n", yn(7, NAN));
    /**
     * yn(1, 0.0) = -inf
     * yn(2, -0.0) = -inf
     * yn(3, 1.5) = -2.073541399060686
     * yn(4, -2.5) = nan
     * yn(5, INFINITY) = 0.000000000000000
     * yn(6, -INFINITY) = nan
     * yn(7, NAN) = nan
     */

Parent topic: Special Functions