Modified Bessel function of the first kind, ordern.
Loading LOADSUB ALL FROM "BESMC.HTS"
or LOADSUB FROM "MATHLIB.HTS"
Usage INTEGER N
REAL X,Y
Y=FNIn(N,X)
Description
FNInreturns the value of the modified cylindrical Bessel function of the first kind and ordernofx,In(x).In(x) is defined for all values ofnand all values ofx, but large absolute values ofxmay cause the absolute value of the result to be larger than MAXREAL, the largest value representable.
Errors
FNIncauses an HTBasic error if its arguments are not of the types listed in the USAGE section, above, or if the result would be larger than MAXREAL.
In(x)
See Also I0, I1e, In, K0
Note
The algorithm used computes the value ofInusing a recursion from the values ofI0 andI1. The computation time increases withnand the computation accuracy decreases withn.