bsplines {pomp} | R Documentation |

## B-spline bases

### Description

These functions generate B-spline basis functions.
`bspline_basis`

gives a basis of spline functions.
`periodic_bspline_basis`

gives a
basis of periodic spline functions.

### Usage

```
bspline_basis(x, nbasis, degree = 3, deriv = 0, names = NULL, rg = range(x))
periodic_bspline_basis(
x,
nbasis,
degree = 3,
period = 1,
deriv = 0,
names = NULL
)
```

### Arguments

`x` |
Vector at which the spline functions are to be evaluated. |

`nbasis` |
The number of basis functions to return. |

`degree` |
Degree of requested B-splines. |

`deriv` |
The order of the derivative required. |

`names` |
optional; the names to be given to the basis functions. These
will be the column-names of the matrix returned. If the names are
specified as a format string (e.g., "basis%d"), |

`rg` |
numeric of length 2; range of the B-spline basis.
To be properly specified, we must have |

`period` |
The period of the requested periodic B-splines. |

### Value

`bspline_basis` |
Returns a matrix with |

`periodic_bspline_basis` |
Returns a matrix with |

If `deriv>0`

, the derivative of that order of each of the corresponding spline basis functions are returned.

### C API

Access to the underlying C routines is available: see the pomp C API document. for definition and documentation of the C API.

### Author(s)

Aaron A. King

### See Also

More on interpolation:
`covariates`

,
`lookup()`

### Examples

```
x <- seq(0,2,by=0.01)
y <- bspline_basis(x,degree=3,nbasis=9,names="basis")
matplot(x,y,type='l',ylim=c(0,1.1))
lines(x,apply(y,1,sum),lwd=2)
x <- seq(-1,2,by=0.01)
y <- periodic_bspline_basis(x,nbasis=5,names="spline%d")
matplot(x,y,type='l')
```

*pomp*version 5.11.0.0 Index]