spatstat.utils (version 3.0-4)

expand.polynom: Expand Symbolic Polynomials in a Formula

Description

Create a formula representing a polynomial, or expand polynomials in an existing formula.

Usage

expand.polynom(f)
  sympoly(x, y, n)

Value

A formula.

Arguments

f

A formula.

x,y

Variable names.

n

Integer specifying the degree of the polynomial. (If n is missing, y will be interpreted as the degree.)

Author

Adrian Baddeley , Rolf Turner and Ege Rubak .

Details

These functions expand a polynomial into its homogeneous terms and return a model formula.

sympoly(x, n) creates a formula whose right-hand side represents the polynomial of degree n in the variable x. Each homogeneous term x^k is a separate term in the formula.

sympoly(x, y, n) creates a formula representing the polynomial of degree n in the two variables x and y.

If f is a formula containing a term of the form polynom(...) then expand.polynom(f) replaces this term by its expansion as a sum of homogeneous terms, as defined in the help for polynom.

See Also

polynom

Examples

   sympoly(A, 4)
   sympoly(A, B, 3)
   expand.polynom(U ~ A + polynom(B, 2))