# polynom

##### Polynomial in One or Two Variables

This function is used to represent a polynomial term in a model
formula.
It computes the homogeneous terms in the polynomial of degree `n`

in one variable `x`

or two variables `x,y`

.

- Keywords
- arith

##### Usage

`polynom(x, …)`

##### Arguments

- x
A numerical vector.

- …
Either a single integer

`n`

specifying the degree of the polynomial, or two arguments`y,n`

giving another vector of data`y`

and the degree of the polynomial.

##### Details

This function is typically used inside a model formula
in order to specify the most general possible polynomial
of order `n`

involving one numerical variable `x`

or two numerical variables `x,y`

.

It is equivalent to `poly(, raw=TRUE)`

.

If only one numerical vector argument `x`

is given,
the function computes the vectors `x^k`

for
`k = 1, 2, …, n`

. These vectors are combined into a matrix
with `n`

columns.

If two numerical vector arguments `x,y`

are given,
the function computes the vectors `x^k * y^m`

for
`k >= 0`

and `m >= 0`

satisfying
`0 < k + m <= n`

. These vectors are combined into a matrix
with one column for each homogeneous term.

##### Value

A numeric matrix, with rows corresponding to the entries of `x`

,
and columns corresponding to the terms in the polynomial.

##### See Also

##### Examples

```
# NOT RUN {
x <- 1:4
y <- 10 * (0:3)
polynom(x, 3)
polynom(x, y, 3)
# }
```

*Documentation reproduced from package spatstat, version 1.61-0, License: GPL (>= 2)*