.BG
.VE $Header: /usr3/s/current/s/.help/RCS/usa,v 1.2 83/12/30 19:36:23 rab Exp $
.FN usa
.TL
usa: Plot United States Coast-line and States
.CS
usa(states, coast, add, xlim, ylim, fifty)
.PP
.AG states
logical flag to control whether state boundaries are
plotted.  Default TRUE.
.AG coast
logical flag to control whether coast-line is plotted.
Default TRUE.
.AG add
logical flag.  If TRUE, plot is superimposed on existing
plot.  Otherwise, a new plot is generated.  Default FALSE.
.AG xlim
optional limits for the x-axis (longitude).  Default is
`c(65,135)'.
.AG ylim
optional limits for the y-axis (latitude).  Default is
`c(24,50)'.
.AG fifty
logical flag.  If TRUE, boxes are drawn in the Pacific Ocean to
represent Alaska and Hawaii.  Default FALSE.
.PP
Graphical parameters may also be supplied as arguments to this
function (see `par').
.PP
The plot is done in correct physical proportion.
The coordinate system set up for the plot uses negative longitude,
so that x-values increase from left to right on the plot.
.EX
usa(states=F) # the u.s. without state lines
usa(xlim=c(65,85),ylim=c(35,50)) #plot the north-east
# the example plot is produced by:
usa
text(state.center,state.abb)
.PI
.KW plot*
.KW aplot*
.KW hplot*
.WR
