R/plotGmap.r

In ragram: Radargrammetry

#' Plot google earth map
#' 
#' Plots a google earth map that shows the location of SAR records. 
#' Uses the \code{\link[dismo]{gmap}} method of the dismo package.
#'  
#' @param object object of the \code{\link{SARSet-class}} 
#' or object of the \code{\link{SAR-class}} (or a subclass e.g. \code{\link{Sentinel-class}} or \code{\link{TSX-class}}).
#' @param xlim the x limits (x1, x2) of the plot. 
#' @param ylim the y limits (y1, y2) of the plot.
#' @param xlab title of the x axis.
#' @param ylab title of the y axis.
#' @param col color within the recorded area.
#' @param sar TRUE if location should be plotted.
#' @param scale 1 or 2. Using 2 doubles the number of pixels returned (and thus gives you better image quality if you need a large image).
#' @param border color of the \code{\link{border}} of the SAR location.
#' @param ... graphical parameters of \code{\link[dismo]{gmap}} method.
#' @export
#' @seealso  \code{\link{plotMap}}, \code{\link[dismo]{gmap}}, \code{\link{border}}, \code{\link{plotBorder}}
#' @examples
#' data(kili)
#'
#' plotGmap(kili)
setGeneric('plotGmap',
           function(object,
                    xlim=c(-5,5)+mean(object@extent[1:2]),
                    ylim=c(-5,5)+mean(object@extent[3:4]),
                    xlab='Longitude', ylab='Latitude', sar=T, 
                    col=rgb(1,0,0,0.5), scale=1, border='black', ...) {
               if(!is.element('maps', installed.packages()[,1])) {
                   stop('Please install the `maps` package first.')
               }
               if(!is.element('dismo', installed.packages()[,1])) {
                   stop('Please install the `dismo` package first.')
               }
               if(!requireNamespace('dismo'))
                   stop('Please load the `dismo` package first')
               if(!requireNamespace('maps'))
                   stop('Please load the `maps` package first')
               plotMap(object, xlab=xlab, ylab=ylab, xlim=xlim, ylim=ylim, 
                       map.default.text = F, sar=F, orbit=F, ...)
               e <- extent(xlim[1], xlim[2],
                           ylim[1], ylim[2])
               tryCatch(plot(dismo::gmap(e, lonlat = T, type='satellite', scale=scale), 
                             inter=T, 
                             xlim=xlim, ylim=ylim, add=T, ...),
                        error=function(error) {
                            print(error)
                            print('Google maps does not answer :-(.')
                            print('Try without projection... ')
                            plot(gmap(e))
                        })
               if(sar)
                   plotBorder(object, col=col, add=T, border=border, ...)
               standardGeneric('plotGmap')
           })

#' @rdname plotGmap
#' @export
setMethod('plotGmap', signature('SAR'), function(object, ...) {
    print('GMap for single SAR object.')
})

#' @rdname plotGmap
#' @export
setMethod('plotGmap', signature('SARSet'), function(object, ...) {
    print('GMap for set of SAR objects.')
})