multipol-package: Multivariate polynomials In multipol: Multivariate Polynomials

Description

Various tools to manipulate and combine multivariate polynomials

Details

 Package: multipol Type: Package Version: 1.0 Date: 2008-01-24 License: GPL

Basically, coerce an array to a multivariate polynomial (a “multipol”) using `as.multipol()`.

Taking a matrix `a` as an example, because this has two dimensions it may be viewed as a bivariate polynomial with `a[i,j]` being the coefficient of x^i.y^j. Note the off-by-one issue; see `?Extract`.

Multivariate polynomials of arbitrary arity are a straightforward generalization using appropriately dimensioned arrays.

Arithmetic operations “`+`”,“`-`”, “`*`”, “`^`” operate as though their arguments are multivariate polynomials.

Even quite small multipols are computationally intense; many coefficients have to be calculated and each is the sum of many terms.

The package would benefit enormously by being able to use a sparse array class.

Author(s)

Robin K. S. Hankin

Maintainer: <[email protected]>

none really

Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```ones(2)*linear(c(1,-1)) # x^2-y^2 ones(2)*(ones(2,2)-uni(2)) # x^3+y^3 a <- as.multipol(matrix(1:12,3,4)) a a[1,1] <- 11 f <- as.function(a*a) f(c(1,pi)) ```

multipol documentation built on March 20, 2018, 5:04 p.m.