Creates a basis expansion from a definition of a smoother using the syntax
of *mgcv*'s smooths via `mgcv::s()`

., `mgcv::te()`

, `mgcv::ti()`

, and
`mgcv::t2()`

, or from a fitted GAM(M).

## Usage

```
basis(object, ...)
# S3 method for gam
basis(
object,
select = NULL,
term = deprecated(),
data = NULL,
n = 100,
n_2d = 50,
n_3d = 16,
n_4d = 4,
partial_match = FALSE,
...
)
# S3 method for scam
basis(
object,
select = NULL,
term = deprecated(),
data = NULL,
n = 100,
n_2d = 50,
n_3d = 16,
n_4d = 4,
partial_match = FALSE,
...
)
# S3 method for gamm
basis(
object,
select = NULL,
term = deprecated(),
data = NULL,
n = 100,
n_2d = 50,
n_3d = 16,
n_4d = 4,
partial_match = FALSE,
...
)
# S3 method for list
basis(
object,
select = NULL,
term = deprecated(),
data = NULL,
n = 100,
n_2d = 50,
n_3d = 16,
n_4d = 4,
partial_match = FALSE,
...
)
# S3 method for default
basis(object, data, knots = NULL, constraints = FALSE, at = NULL, ...)
```

## Arguments

- object
a smooth specification, the result of a call to one of

`mgcv::s()`

.,`mgcv::te()`

,`mgcv::ti()`

, or`mgcv::t2()`

, or a fitted GAM(M) model.- ...
other arguments passed to

`mgcv::smoothCon()`

.- select
character; select smooths in a fitted model

- term
- data
a data frame containing the variables used in

`smooth`

.- n
numeric; the number of points over the range of the covariate at which to evaluate the smooth.

- n_2d
numeric; the number of new observations for each dimension of a bivariate smooth. Not currently used;

`n`

is used for both dimensions.- n_3d
numeric; the number of new observations to generate for the third dimension of a 3D smooth.

- n_4d
numeric; the number of new observations to generate for the dimensions higher than 2 (!) of a

*k*D smooth (*k*>= 4). For example, if the smooth is a 4D smooth, each of dimensions 3 and 4 will get`n_4d`

new observations.- partial_match
logical; in the case of character

`select`

, should`select`

match partially against`smooths`

? If`partial_match = TRUE`

,`select`

must only be a single string, a character vector of length 1.- knots
a list or data frame with named components containing knots locations. Names must match the covariates for which the basis is required. See

`mgcv::smoothCon()`

.- constraints
logical; should identifiability constraints be applied to the smooth basis. See argument

`absorb.cons`

in`mgcv::smoothCon()`

.- at
a data frame containing values of the smooth covariate(s) at which the basis should be evaluated.