Returns or evaluates orthogonal polynomials of degree 1 to
degree over the specified set of points
x. These are all orthogonal to the constant polynomial of degree 0. Alternatively, evaluate raw polynomials.
poly(x, ..., degree = 1, coefs = NULL, raw = FALSE) polym(..., degree = 1, raw = FALSE) ## S3 method for class 'poly': predict((object, newdata, ...))
- x, newdata
- a numeric vector at which to evaluate the polynomial.
xcan also be a matrix. Missing values are not allowed in
- the degree of the polynomial. Must be less than the number of unique points if
raw = TRUE.
- for prediction, coefficients from a previous fit.
- if true, use raw and not orthogonal polynomials.
- an object inheriting from class
"poly", normally the result of a call to
polywith a single vector argument.
poly, polym: further vectors.
predict.poly: arguments to be passed to or from other methods.
degree should be named (as it follows
...), an unnamed second argument of length 1 will be interpreted as the degree. The orthogonal polynomial is summarized by the coefficients, which can be used to evaluate it via the three-term recursion given in Kennedy & Gentle (1980, pp. 343--4), and used in the
predict part of the code.
poly with a single vector argument:
A matrix with rows corresponding to points in
x and columns corresponding to the degree, with attributes
"degree" specifying the degrees of the columns and (unless
raw = TRUE)
"coefs" which contains the centering and normalization constants used in constructing the orthogonal polynomials. The matrix has given class
Chambers, J. M. and Hastie, T. J. (1992) Statistical Models in S. Wadsworth & Brooks/Cole.
Kennedy, W. J. Jr and Gentle, J. E. (1980) Statistical Computing Marcel Dekker.
This routine is intended for statistical purposes such as
contr.poly: it does not attempt to orthogonalize to machine accuracy.
Documentation reproduced from R 2.15.3. License: GPL-2.