% File src/library/grid/man/grid.rect.Rd
% Part of the R package, http://www.R-project.org
% Copyright 1995-2007 R Core Development Team
% Distributed under GPL 2 or later

\name{grid.rect}
\alias{grid.rect}
\alias{rectGrob}
\title{Draw rectangles }
\description{
  These functions create and draw rectangles.
}
\usage{
grid.rect(x = unit(0.5, "npc"), y = unit(0.5, "npc"),
          width = unit(1, "npc"), height = unit(1, "npc"),
          just = "centre", hjust = NULL, vjust = NULL,
          default.units = "npc", name = NULL,
          gp=gpar(), draw = TRUE, vp = NULL)
rectGrob(x = unit(0.5, "npc"), y = unit(0.5, "npc"),
         width = unit(1, "npc"), height = unit(1, "npc"),
         just = "centre", hjust = NULL, vjust = NULL, 
         default.units = "npc", name = NULL,
         gp=gpar(), vp = NULL)
}
\arguments{
  \item{x}{A numeric vector or unit object specifying x-location.}
  \item{y}{A numeric vector or unit object specifying y-location.}
  \item{width}{A numeric vector or unit object specifying width.}
  \item{height}{A numeric vector or unit object specifying height.}
  \item{just}{The justification of the rectangle 
    relative to its (x, y) location.  If there are two values, the first
    value specifies horizontal justification and the second value specifies
    vertical justification.  Possible string values are: \code{"left"},
    \code{"right"}, \code{"centre"}, \code{"center"}, \code{"bottom"},
    and \code{"top"}.  For numeric values, 0 means left alignment
    and 1 means right alignment.
  }
  \item{hjust}{A numeric vector specifying horizontal justification.
    If specified, overrides the \code{just} setting.}
  \item{vjust}{A numeric vector specifying vertical justification.
    If specified, overrides the \code{just} setting.}
  \item{default.units}{A string indicating the default units to use
    if \code{x}, \code{y}, \code{width}, or \code{height}
    are only given as numeric vectors.}  
  \item{name}{ A character identifier. }
  \item{gp}{An object of class \code{gpar}, typically the output
    from a call to the function \code{gpar}.  This is basically
    a list of graphical parameter settings.}
  \item{draw}{A logical value indicating whether graphics output
    should be produced.}
  \item{vp}{A Grid viewport object (or NULL).}
}
\details{
  Both functions create a rect grob (a graphical object describing
  rectangles), but only \code{grid.rect}
  draws the rectangles (and then only if \code{draw} is \code{TRUE}).
  
}
\value{
  A rect grob.  \code{grid.rect} returns the value invisibly.
}
\author{Paul Murrell}
\seealso{
  \link{Grid},
  \code{\link{viewport}}
}
\keyword{dplot}
