Struve: Modified Struve functions and related functions

In RandomFieldsUtils: Utilities for the Simulation and Analysis of Random Fields and Genetic Data

Modified Struve functions and related functions

Description

These functions return the values of the modified Struve functions and related functions

Usage

struveH(x, nu) 
struveL(x, nu, expon.scaled=FALSE)
I0L0(x)

Arguments

x	non-negative numeric vector
nu	numeric vector
expon.scaled	logical; if TRUE, the results are exponentially scaled in order to avoid overflow or underflow respectively.

Details

I0L0 returns besselI(nu=0). minus struveL(nu=0).

Value

Numeric vector with the (scaled, if expon.scaled = TRUE) values of the corresponding function.

The length of the result is the maximum of the lengths of the arguments x and nu. The two arguments are recycled to that length.

References

• MacLeod, A.J. (1993) Chebyshev expansions for modified Struve and related functions, Mathematics of Computation, 60, 735-747

• Abramowitz, M., and Stegun, I.A. (1984) Pocketbook of Mathematical Functions, Verlag Harry Deutsch

See Also

besselI

Examples

if (FALSE) {

x <- seq(1, 2, 0.1)
struveH(x, 0)
struveH(x, 1)

I0L0(x) - (besselI(x, nu=0) - struveL(x, 0)) 
besselI(x, nu=1) - struveL(x, 1) ## cf. Abramovitz & Stegun, table 12.1

}

RandomFieldsUtils documentation built on April 19, 2022, 5:09 p.m.