mapAxis: Add Axis Labels to an Existing Map
In oce: Analysis of Oceanographic Data

mapAxis

R Documentation

Add Axis Labels to an Existing Map

Description

Plot axis labels on an existing map. This is an advanced function, requiring coordination with mapPlot() and (possibly) also with mapGrid(), and so it is best avoided by novices, who may be satisfied with the defaults used by mapPlot().

Usage

mapAxis(
  side = 1:2,
  longitude = TRUE,
  latitude = TRUE,
  axisStyle = 1,
  tick = TRUE,
  line = NA,
  pos = NA,
  outer = FALSE,
  font = NA,
  lty = "solid",
  lwd = 1,
  lwd.ticks = lwd,
  col = NULL,
  col.ticks = NULL,
  hadj = NA,
  padj = NA,
  tcl = -0.3,
  cex.axis = 1,
  mgp = c(0, 0.5, 0),
  debug = getOption("oceDebug")
)

Arguments

`side`	the side at which labels are to be drawn. If not provided, sides 1 and 2 will be used (i.e. bottom and left-hand sides).
`longitude`	either a logical value or a numeric vector of longitudes. There are three possible cases: (1) If `longitude=TRUE` (the default) then ticks and nearby numbers will occur at the longitude grid established by the previous call to `mapPlot()`; (2) if `longitude=FALSE` then no longitude ticks or numbers are drawn; (3) if `longitude` is a vector of numerical values, then those ticks are placed at those values, and numbers are written beside them. Note that in cases 1 and 3, efforts are made to avoid overdrawing text, so some longitude values might get ticks but not numbers. To get ticks but not numbers, set `cex.axis=0`.
`latitude`	similar to `longitude` but for latitude.
`axisStyle`	an integer specifying the style of labels for the numbers on axes. The choices are: 1 for signed numbers without additional labels; 2 (the default) for unsigned numbers followed by letters indicating the hemisphere; 3 for signed numbers followed by a degree sign; 4 for unsigned numbers followed by a degree sign; and 5 for signed numbers followed by a degree sign and letters indicating the hemisphere.
`tick`	parameter passed to `axis()`.
`line`	parameter passed to `axis()`.
`pos`	parameter passed to `axis()`.
`outer`	parameter passed to `axis()`.
`font`	axis font, passed to `axis()`.
`lty`	axis line type, passed to `axis()`.
`lwd`	axis line width, passed to `axis()`).
`lwd.ticks`	tick line width, passed to `axis()`.
`col`	axis color, passed to `axis()`.
`col.ticks`	axis tick color, passed to `axis()`.
`hadj`	an argument that is transmitted to `axis()`.
`padj`	an argument that is transmitted to `axis()`.
`tcl`	axis-tick size (see `par()`).
`cex.axis`	axis-label expansion factor (see `par()`); set to 0 to prevent numbers from being placed in axes.
`mgp`	three-element numerical vector describing axis-label placement (see `par()`). It usually makes sense to set the first and third elements to zero.
`debug`	a flag that turns on debugging. Set to 1 to get a moderate amount of debugging information, or to 2 to get more.

Author(s)

Dan Kelley

Examples


library(oce)
data(coastlineWorld)
par(mar = c(2, 2, 1, 1))
lonlim <- c(-180, 180)
latlim <- c(70, 110)
# In mapPlot() call, note axes and grid args, to
# prevent over-plotting of defaults.  Some adjustments
# might be required to the mapGrid() arguments, to
# get agreement with the axis. This is why both
# mapGrid() and mapAxis() are best avoided; it is
# simpler to let mapPlot() handle these things.
mapPlot(coastlineWorld,
    projection = "+proj=stere +lat_0=90",
    longitudelim = lonlim, latitudelim = latlim,
    col = "tan", axes = FALSE, grid = FALSE
)
mapGrid(15, 15)
mapAxis(axisStyle = 5)

oce documentation built on Sept. 11, 2024, 7:09 p.m.