| horner {cmna} | R Documentation |
Horner's rule
Description
Use Horner's rule to evaluate a polynomial
Usage
horner(x, coefs)
rhorner(x, coefs)
naivepoly(x, coefs)
betterpoly(x, coefs)
Arguments
x |
a vector of x values to evaluate the polynomial |
coefs |
vector of coefficients of x |
Details
This function implements Horner's rule for fast polynomial
evaluation. The implementation expects x to be a vector of x
values at which to evaluate the polynomial. The parameter coefs
is a vector of coefficients of x. The vector order is such
that the first element is the constant term, the second element is
the coefficient of x, the so forth to the highest degreed
term. Terms with a 0 coefficient should have a 0 element in the
vector.
The function rhorner implements the the Horner algorithm
recursively.
The function naivepoly implements a polynomial evaluator using
the straightforward algebraic approach.
The function betterpoly implements a polynomial evaluator using
the straightforward algebraic approach with cached x terms.
Value
the value of the function at x
See Also
Other algebra:
bilinear(),
cubicspline(),
division,
fibonacci(),
isPrime(),
linterp(),
nthroot(),
polyinterp(),
pwiselinterp(),
quadratic()
Examples
b <- c(2, 10, 11)
x <- 5
horner(x, b)
b <- c(-1, 0, 1)
x <- c(1, 2, 3, 4)
horner(x, b)
rhorner(x, b)