R/adjust.grd.R

In geo: Draw and Annotate Maps, Especially Charts of the North Atlantic

#' Adjusts grid for plot in Lambert projection.
#' 
#' Adjusts grid for plot in Lambert projection.
#' 
#' 
#' @param ply gridline??
#' @param rat curvature or slant???
#' @return Returns diagonal or curved lines for use in grid on Lambert
#' projected plots.
#' @note Needs elaboration. Utility, internal, might be hidden?
#' @seealso \code{\link{findline}}, \code{\link{gridaxes.Lambert}}
#' @keywords manip aplot
#' @export adjust.grd
adjust.grd <-
function(ply, rat = 0.025)
{


#' Parameters for the geo plot functions.
#' 
#' The \pkg{geo} functions rely on the parameters in \code{options("geopar")}
#' for plotting. Every time \code{geoplot} is called a new set of geopar is
#' made and the current erased. If you want to change the parameters in the
#' background plot after you call geosubplot you have to save the current
#' geopar before calling geosubplot. When reassigning geopar, the command
#' \code{options(geopar=list(...))} must be used.
#' 
#' When using \code{geosubplot} it is important to save these parameters before
#' the subplot is plotted if one wants to make changes to the large plot
#' afterwards.
#' 
#' 
#' @examples
#' 
#' \dontrun{geoplot(type="l")
#' large.geopar <- geopar                          # Parameters saved.
#' 
#' pos <- list(lat=c(63,64),lon=c(-27,-24))    
#' geosubplot(geoplot(island, new=TRUE,type="l"),pos) # Plot subplot at pos.
#' geopolygon(island,col=3)                        # Fill with color.      
#' geotext(65,-18,"subplot",col=150)               # Text on subplot.
#' small.geopar <- geopar                          # Parameters for subplot saved.
#' 
#' geopar <- large.geopar                          # Make big plot active.
#' geopolygon(island,col=150)                      # Fill with color.
#' geotext(65,-18.5,"Big plot",csi=8,col=3)        # Text on big plot.
#' 
#' pos <- list(lat=c(63,64),lon=c(-15,-12))
#' geosubplot(geoplot(island,new=T,type="l"),pos)  # Another subplot drawn.
#' geopolygon(island,col=3)                        # Fill with color.
#' geotext(65,-18,"subplot # 2",col=150)           # Text on subplot #2.
#' small.geopar.2 <- geopar                        # Parameters for subplot saved.
#' 
#' # This must put in a script and sourced together to work like meant to here.
#' # If done in command line, assign() must be used for changing geopar.
#' }
#' @export geopar
	geopar <- getOption("geopar")
	gx <- geopar$limx
	gy <- geopar$limy
	bx1 <- list(x = c(gx[1], gx[2], gx[2], gx[1], gx[1]), y = c(gy[1],
		gy[1], gy[2], gy[2], gy[1]))
	gx <- mean(gx) + (1 - rat) * (gx - mean(gx))
	gy <- mean(gy) + (1 - rat) * (gy - mean(gy))
	bx1 <- list(x = c(gx[1], gx[2], gx[2], gx[1], gx[1], bx1$x), y = c(
		gy[1], gy[1], gy[2], gy[2], gy[1], bx1$y))
	ply <- findline(ply, bx1)
	return(ply)
}