ChapterPn

LeGendre function of the first kind.

Loading LOADSUB ALL FROM "LEGENDRE.HTS"

or LOADSUB FROM "MATHLIB.HTS"

Usage INTEGER N

REAL X,Y

Y=FNPn(N,X)

Description

FNPn returns the value of the Legendre function of the first kind, degree zero, and order n of x, Pn(x), into the real variable Y. N must be positive or zero.

Errors

FNPn causes an HTBasic error if its arguments are not of the types listed in the USAGE section, above, if n < 0, or if the polynomial's absolute value would be larger than MAXREAL, the largest value representable.

See Also

P1n, Qn

Pn(x)

Note

For n > 12, the algorithm used computes the value of Pn using a recursion from the values of P1 and P2. The computation time increases with n - 11 and the computation accuracy decreases with n - 11.