Ine

Scaled modified Bessel function of the first kind, order one.

Loading LOADSUB ALL FROM "BESMC.HTS"

or LOADSUB FROM "MATHLIB.HTS"

Usage INTEGER N

REAL X,Y

Y=FNIne(N,X)

Description

FNIne returns the value of the modified cylindrical Bessel function of the first kind and order n of x scaled by e|x|, e-|x|In(x). The scaling is done so that the value of In(x) can be evaluated for arguments of large absolute value, where the absolute value of In(x) may be larger than MAXREAL, the largest value representable. The absolute value of e-|x|In(x) is moderate for arguments of large absolute value.

Errors

FNIne causes an HTBasic error if its arguments are not of the types listed in the USAGE section, above.

e-|x|In(x)

See Also I0, I0e, In, K0

Note

The algorithm used computes the value of In using a recursion from the values of I0 and I1. The computation time increases with n and the computation accuracy decreases with n.