R: Useful Prepanel Function for Lattice

F_3_prepanel.functions {lattice} | R Documentation

## Useful Prepanel Function for Lattice

### Description

These are predefined prepanel functions available in Lattice.

### Usage

    prepanel.lmline(x, y, ...)
    prepanel.qqmathline(x, y = x, distribution = qnorm,
                        probs = c(0.25, 0.75), qtype = 7,
                        groups, subscripts,
                        ...)
    prepanel.loess(x, y, span, degree, family, evaluation,
                   horizontal = FALSE, ...)
    prepanel.spline(x, y, npoints = 101,
                    horizontal = FALSE, ...,
                    keep.data = FALSE)

### Arguments

`x, y` | x and y values, numeric or factor
`distribution` | quantile function for theoretical distribution. This is automatically passed in when this is used as a prepanel function in `qqmath`.
`qtype` | type of `quantile`
`probs` | numeric vector of length two, representing probabilities. If used with `aspect="xy"`, the aspect ratio will be chosen to make the line passing through the corresponding quantile pairs as close to 45 degrees as possible.
`span, degree, family, evaluation` | Arguments controlling the underlying `loess` smooth.
`horizontal, npoints` | See documentation for corresponding panel function.
`keep.data` | Ignored. Present to capture argument of the same name in `smooth.spline`.
`groups, subscripts` | See `xyplot`. Whenever appropriate, calculations are done separately for each group and then combined.
`...` | Other arguments. These are passed on to other functions if appropriate (in particular, `smooth.spline`), and ignored otherwise.

### Details

All these prepanel functions compute the limits to be large enough to contain all points as well as the relevant smooth.

In addition, `prepanel.lmline` computes the `dx` and `dy` such that it reflects the slope of the linear regression line; for `prepanel.qqmathline`, this is the slope of the line passing through the quantile pairs specified by `probs`. For `prepanel.loess` and `prepanel.spline`, `dx` and `dy` reflect the piecewise slopes of the nonlinear smooth.

### Value

usually a list with components `xlim`, `ylim`, `dx` and `dy`, the first two being used to calculate panel axes limits, the last two for banking computations. The form of these components are described under `xyplot`. There are also several prepanel functions that serve as the default for high level functions, see `prepanel.default.xyplot`

### Author(s)

Deepayan Sarkar Deepayan.Sarkar@R-project.org

### See Also

Lattice, `xyplot`, `banking`, `panel.loess`, `panel.spline`.

[Package lattice version 0.20-29 Index]