R: Useful Panel Functions

panel.functions {lattice}

R Documentation

Useful Panel Functions

Description

These are predefined panel functions available in lattice for use in constructing new panel functions (usually on-the-fly).

Usage


panel.abline(a = NULL, b = 0,
             h = NULL, v = NULL,
             reg = NULL, coef = NULL,
             col, col.line, lty, lwd, alpha, type,
             ...,
             reference = FALSE)
panel.refline(...) 

panel.curve(expr, from, to, n = 101,
            curve.type = "l",
            col, lty, lwd, type,
            ...)
panel.rug(x = NULL, y = NULL,
          regular = TRUE, 
          start = if (regular) 0 else 0.97,
          end = if (regular) 0.03 else 1,
          x.units = rep("npc", 2),
          y.units = rep("npc", 2),
          col, lty, lwd, alpha,
          ...)
panel.average(x, y, fun = mean, horizontal = TRUE,
              lwd, lty, col, col.line, type,
              ...)
panel.linejoin(x, y, fun = mean, horizontal = TRUE,
               lwd, lty, col, col.line, type,
               ...)

panel.fill(col, border, ...)
panel.grid(h=3, v=3, col, col.line, lty, lwd, ...)
panel.lmline(x, y, ...)
panel.loess(x, y, span = 2/3, degree = 1,
            family = c("symmetric", "gaussian"),
            evaluation = 50,
            lwd, lty, col, col.line, type,
            horizontal = FALSE,
            ...)
panel.mathdensity(dmath = dnorm, args = list(mean=0, sd=1),
                  n = 50, col, col.line, lwd, lty, type,
                  ...)

Arguments

`x, y`	variables defining the contents of the panel
`a, b`	Coefficients of the line to be added by `panel.abline`. `a` can be a vector of length 2, representing the coefficients of the line to be added, in which case `b` should be missing. `a` can also be an appropriate ‘regression’ object, i.e., an object which has a `coef` method that returns a length 2 numeric vector. The corresponding line will be plotted. The `reg` argument will override `a` if specified.
`coef`	Coefficients of the line to be added as a length 2 vector
`reg`	A regression object. The corresponding fitted line will be drawn
`h, v`	For `panel.abline`, these are numeric vectors giving locations respectively of horizontal and vertical lines to be added to the plot, in native coordinates. For `panel.grid`, these usually specify the number of horizontal and vertical reference lines to be added to the plot. Alternatively, they can be negative numbers. `h=-1` and `v=-1` are intended to make the grids aligned with the axis labels. This doesn't always work; all that actually happens is that the locations are chosen using `pretty`, which is also how the label positions are chosen in the most common cases (but not for factor or date-time variables, for instance). `h` and `v` can be negative numbers other than `-1`, in which case `-h` and `-v` (as appropriate) is supplied as the `n` argument to `pretty`.
`reference`	logical indicating whether the default graphical parameters for `panel.abline` should be taken from the “reference.line” parameter settings. The default is to take them from the “add.line” settings. The `panel.refline` function is a wrapper around `panel.abline` that calls it with `reference=TRUE`.
`expr`	expression as a function of x or a function to plot as a curve
`n`	the number of points to use for drawing the curve
`regular`	logical indicating whether the ‘rug’ is to be drawn on the regular side (left / bottom) or not (right / top)
`start, end`	endpoints of rug segments, in normalized parent coordinates (between 0 and 1). Defaults depend on value of regular, and cover 3% of the panel width and height
`x.units, y.units`	character vector, replicated to be of length two. Specifies the (grid) units associated with `start` and `end` above. `x.units` and `y.units` are for the rug on the x-axis and y-axis respectively (and thus are associated with `start` and `end` values on the y and x scales respectively).
`from, to`	optional lower and upper x-limits of curve. If missing, limits of current panel are used
`curve.type`	type of curve (`"p"` for points, etc), passed to `llines`
`col, col.line, lty, lwd, alpha, border`	graphical parameters
`type`	passed on to `panel.points` by `panel.average`, but is usually ignored by the other panel functions documented here. In such cases, the argument is present only to make sure an explicitly specified `type` argument (perhaps meant for another function) doesn't affect the display.
`span, degree, family, evaluation`	arguments to `loess.smooth`, for which `panel.loess` is essentially a wrapper.
`fun`	the function that will be applied to the subset of x(y) determined by the unique values of y(x)
`horizontal`	logical. If FALSE, the plot is ‘transposed’ in the sense that the behaviours of x and y are switched. x is now the ‘factor’. Interpretation of other arguments change accordingly. See documentation of `bwplot` for a fuller explanation.
`dmath`	A vectorized function that produces density values given a numeric vector named `x`, e.g., `dnorm`
`args`	list giving additional arguments to be passed to dmath
`...`	graphical parameters can be supplied. see function definition for details. Color can usually be specified by `col`, `col.line` and `col.symbol`, the last two overriding the first for lines and points respectively.

Details

panel.abline adds a line of the form y=a+bx or vertical and/or horizontal lines. Graphical parameters are obtained from the “add.line” settings by default. panel.refline is similar, but uses the “reference.line” settings for the defaults.

panel.grid draws a reference grid.

panel.curve adds a curve, similar to what curve does with add = TRUE. Graphical parameters for the line are obtained from the add.line setting.

panel.average treats one of x and y as a factor (according to the value of horizontal), calculates fun applied to the subsets of the other variable determined by each unique value of the factor, and joins them by a line. Can be used in conjunction with panel.xyplot and more commonly with panel.superpose to produce interaction plots. See xyplot documentation for an example. panel.linejoin is an alias for panel.average retained for back-compatibility and may go away in future.

panel.mathdensity plots a (usually theoretical) probability density function. This can be useful in conjunction with histogram and densityplot to visually estimate goodness of fit (note, however, that qqmath is more suitable for this).

panel.rug adds a rug representation of the (marginal) data to the panel, much like rug.

panel.lmline(x, y) is equivalent to panel.abline(lm(y~x)).

Author(s)