1% File src/library/grid/man/grid.xaxis.Rd
2% Part of the R package, https://www.R-project.org
3% Copyright 1995-2020 R Core Team
4% Distributed under GPL 2 or later
5
6\name{grid.xaxis}
7\alias{grid.xaxis}
8\alias{xaxisGrob}
9\title{Draw an X-Axis}
10\description{
11  These functions create and draw an x-axis.
12}
13\usage{
14grid.xaxis(at = NULL, label = TRUE, main = TRUE,
15           edits = NULL, name = NULL,
16           gp = gpar(), draw = TRUE, vp = NULL)
17
18xaxisGrob(at = NULL, label = TRUE, main = TRUE,
19          edits = NULL, name = NULL,
20          gp = gpar(), vp = NULL)
21}
22\arguments{
23  \item{at}{A numeric vector of x-value locations for the tick marks.}
24  \item{label}{A logical value indicating whether to draw the labels
25    on the tick marks, or an expression or character vector which
26    specify the labels to use.  If not logical, must be the same
27    length as the \code{at} argument.}
28  \item{main}{A logical value indicating whether to draw the axis
29    at the bottom (\code{TRUE}) or at the top (\code{FALSE}) of the
30    viewport.}
31  \item{edits}{A gEdit or gEditList containing edit operations
32    to apply (to the children of the axis)
33    when the axis is first created and during redrawing
34    whenever \code{at} is \code{NULL}.
35    }
36  \item{name}{ A character identifier. }
37  \item{gp}{An object of class \code{"gpar"}, typically the output
38    from a call to the function \code{\link{gpar}}.  This is basically
39    a list of graphical parameter settings.}
40  \item{draw}{A logical value indicating whether graphics output
41    should be produced.}
42  \item{vp}{A Grid viewport object (or \code{NULL}).}
43}
44\details{
45  Both functions create an xaxis grob (a graphical object describing an
46  xaxis), but only \code{grid.xaxis}
47  draws the xaxis (and then only if \code{draw} is \code{TRUE}).
48}
49\value{
50  An xaxis grob.  \code{grid.xaxis} returns the value invisibly.
51}
52\section{Children}{
53  If the \code{at} slot of an xaxis grob is not \code{NULL} then
54  the xaxis will have the following children:
55  \describe{
56    \item{major}{ representing the line at the base of the
57    tick marks.}
58    \item{ticks}{representing the tick marks.}
59    \item{labels}{representing the tick labels.}
60  }
61
62  If the \code{at} slot is \code{NULL} then there are no children
63  and ticks are drawn based on the current viewport scale.
64}
65\author{Paul Murrell}
66\seealso{
67  \link{Grid},
68  \code{\link{viewport}},
69  \code{\link{grid.yaxis}}
70}
71\keyword{dplot}
72