Poly: Polynomials

Description Usage Arguments Details Author(s) References Examples

Description

Polynomial functions as per the Gnu Scientific Library, reference manual section 6.1. These functions are defined in header file gsl_poly.h

Usage

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gsl_poly(c_gsl,x)

Arguments

c_gsl

Coefficients of the poynomial (c in the function definition and the GSL ref manual) starting at the constant term and ending in the highest power; see details section. This argument is called “c_gsl” (and not “c”) to avoid confusion with R function c()

x

input: real values

Details

One must be careful to avoid off-by-one errors. In C idiom, the function evaluates the polynomial

c[0]+c[1]+...+c[len-1]x^(len-1)

where len is the second argument of GSL function gsl_poly_eval().

The R idiom would be

c[1]+c[2]+...+c[len]x^(len-1).

This section is work-in-progress and more will be added when I have the time/need for the other functions here.

Author(s)

Robin K. S. Hankin

References

http://www.gnu.org/software/gsl

Examples

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a <- matrix(1:4,2,2)
rownames(a) <- letters[1:2]
(jj <- gsl_poly(1:3,a))

jj-(1 + 2*a + 3*a^2)  #should be small

gsl documentation built on May 29, 2017, 12:57 p.m.