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