R: Replacements of traditional graphics functions

F_2_llines {lattice}

R Documentation

Replacements of traditional graphics functions

Description

These functions are intended to replace common low level traditional graphics functions, primarily for use in panel functions. The originals can not be used (at least not easily) because lattice panel functions need to use grid graphics. Low level drawing functions in grid can be used directly as well, and is often more flexible. These functions are provided for convenience and portability.

Usage

lplot.xy(xy, type, pch, lty, col, cex, lwd,
         font, fontfamily, fontface,
         col.line, col.symbol, alpha, fill,
         origin = 0, ..., identifier, name.type)

llines(x, ...)
lpoints(x, ...)
ltext(x, ...)

## Default S3 method:
llines(x, y = NULL, type = "l",
       col, alpha, lty, lwd, ..., identifier, name.type)
## Default S3 method:
lpoints(x, y = NULL, type = "p", col, pch, alpha, fill,
        font, fontfamily, fontface, cex, ..., identifier, name.type)  
## Default S3 method:
ltext(x, y = NULL, labels = seq_along(x),
      col, alpha, cex, srt = 0,
      lineheight, font, fontfamily, fontface,
      adj = c(0.5, 0.5), pos = NULL, offset = 0.5, ..., identifier, name.type)  

lsegments(x0, y0, x1, y1, x2, y2,
          col, alpha, lty, lwd,
          font, fontface, ..., identifier, name.type)
lrect(xleft, ybottom, xright, ytop,
      x = (xleft + xright) / 2,
      y = (ybottom + ytop) / 2,
      width = xright - xleft,
      height = ytop - ybottom,
      col = "transparent",
      border = "black",
      lty = 1, lwd = 1, alpha = 1,
      just = "center",
      hjust = NULL, vjust = NULL,
      font, fontface,
      ..., identifier, name.type)
larrows(x0 = NULL, y0 = NULL, x1, y1, x2 = NULL, y2 = NULL,
        angle = 30, code = 2, length = 0.25, unit = "inches",
        ends = switch(code, "first", "last", "both"),
        type = "open",
        col = add.line$col,
        alpha = add.line$alpha,
        lty = add.line$lty,
        lwd = add.line$lwd,
        fill = NULL, 
        font, fontface,
        ..., identifier, name.type)
lpolygon(x, y = NULL,
         border = "black", col = "transparent", fill = NULL, 
         font, fontface, ..., identifier, name.type)

panel.lines(...)
panel.points(...)
panel.segments(...)
panel.text(...)
panel.rect(...)
panel.arrows(...)
panel.polygon(...)

Arguments

`x, y, x0, y0, x1, y1, x2, y2, xy`	locations. `x2` and `y2` are available for for S compatibility.
`length, unit`	determines extent of arrow head. `length` specifies the length in terms of `unit`, which can be any valid grid unit as long as it doesn't need a `data` argument. `unit` defaults to inches, which is the only option in the base version of the function, `arrows`.
`angle, code, type, labels, srt, adj, pos, offset`	arguments controlling behaviour. See respective base functions for details. For `larrows` and `panel.larrows`, `type` is either `"open"` or `"closed"`, indicating the type of arrowhead.
`ends`	serves the same function as `code`, using descriptive names rather than integer codes. If specified, this overrides `code`
`col, alpha, lty, lwd, fill, pch, cex, lineheight, font, fontfamily, fontface, col.line, col.symbol, border`	graphical parameters. `fill` applies to points when `pch` is in `21:25` and specifies the fill color, similar to the `bg` argument in the base graphics function `points`. For devices that support alpha-transparency, a numeric argument `alpha` between 0 and 1 can controls transparency. Be careful with this, since for devices that do not support alpha-transparency, nothing will be drawn at all if this is set to anything other than 0. `fill`, `font` and `fontface` are included in `lrect`, `larrows`, `lpolygon`, and `lsegments` only to ensure that they are not passed down (as `gpar` does not like them).
`origin`	for `type="h"` or `type="H"`, the value to which lines drop down.
`xleft, ybottom, xright, ytop`	see `rect`
`width, height, just, hjust, vjust`	finer control over rectangles, see `grid.rect`
`...`	extra arguments, passed on to lower level functions as appropriate.
`identifier`	A character string that is prepended to the name of the grob that is created.
`name.type`	A character value indicating whether the name of the grob should have panel or strip information added to it. Typically either `"panel"`, `"strip"`, `"strip.left"`, or `""` (for no extra information).

Details

These functions are meant to be grid replacements of the corresponding base R graphics functions, to allow existing Trellis code to be used with minimal modification. The functions panel.* are essentally identical to the l* versions, are recommended for use in new code (as opposed to ported code) as they have more readable names.

See the documentation of the base functions for usage. Not all arguments are always supported. All these correspond to the default methods only.

Note

There is a new type="H" option wherever appropriate, which is similar to type="h", but with horizontal lines.

Author(s)

Deepayan Sarkar Deepayan.Sarkar@R-project.org