R: Panel Function to Add a Spline Smooth

F_2_panel.spline {lattice} | R Documentation

## Panel Function to Add a Spline Smooth

### Description

A predefined panel function that can be used to add a spline smooth based on the provided data.

### Usage

    panel.spline(x, y, npoints = 101,
                 lwd = plot.line$lwd,
                 lty = plot.line$lty,
                 col, col.line = plot.line$col,
                 type,
                 horizontal = FALSE, ...,
                 keep.data = FALSE,
                 identifier = "spline")

### Arguments

`x, y` | Variables defining the data to be used.
`npoints` | The number of equally spaced points within the range of the predictor at which the fitted model is evaluated for plotting.
`lwd, lty, col, col.line` | Graphical parameters for the added line. `col.line` overrides `col`.
`type` | Ignored. The argument is present only to make sure that an explicitly specified `type` argument (perhaps meant for another function) does not affect the display.
`horizontal` | A logical flag controlling which variable is to be treated as the predictor (by default `x`) and which as the response (by default `y`). If `TRUE`, the plot is ‘transposed’ in the sense that `y` becomes the predictor and `x` the response. (The name ‘horizontal’ may seem an odd choice for this argument, and originates from similar usage in `bwplot`).
`keep.data` | Passed on to `smooth.spline`. The default here (`FALSE`) is different, and results in the original data not being retained in the fitted spline model. It may be useful to set this to `TRUE` if the return value of `panel.spline`, which is the fitted model as returned by `smooth.spline`, is to be used for subsequent computations.
`...` | Extra arguments, passed on to `smooth.spline` and `panel.lines` as appropriate.
`identifier` | A character string that is prepended to the names of grobs that are created by this panel function.

### Value

The fitted model as returned by `smooth.spline`.

### Author(s)

Deepayan Sarkar Deepayan.Sarkar@R-project.org

### See Also

Lattice, `smooth.spline`, `prepanel.spline`

[Package lattice version 0.20-29 Index]