started fxn to visualize wkt area, not sure if best fit yet #34

NAMESPACE

@@ -27,6 +27,7 @@ export(spocc_rcharts_togeojson)
 export(spocc_stylegeojson)
 export(spocc_togeojson)
 export(wkt2bbox)
+export(wkt_vis)
 import(AntWeb)
 import(XML)
 import(assertthat)

R/wkt_vis.r

@@ -0,0 +1,35 @@
+#' Visualize well-known text area's on a map.
+#' 
+#' This can be helpful in visualizing the area in which you are searching for 
+#' occurrences with the \code{occ} function. 
+#'
+#' @import ggmap ggplot2 assertthat rgeos
+#' @param x Input well-known text area (character)
+#' @param zoom Zoom level, defaults to 6 (numeric)
+#' @param maptype Map type, default is terrain (character)
+#' @export
+#' @examples \dontrun{
+#' poly <- 'POLYGON((-111.06 38.84, -110.80 39.37, -110.20 39.17, -110.20 38.90, -110.63 38.67, -111.06 38.84))'
+#' wkt_vis(poly)
+#' 
+#' poly2 <- 'POLYGON((-125 38.4,-125 40.9,-121.8 40.9,-121.8 38.4,-125 38.4))'
+#' wkt_vis(poly2)
+#' }
+
+wkt_vis <- function(x, zoom = 6, maptype = "terrain")
+{
+  assert_that(!is.null(x))
+  assert_that(is.character(x))
+
+  poly_wkt <- readWKT(x)
+  df <- fortify(poly_wkt)
+  center_lat <- min(df$lat) + (max(df$lat) - min(df$lat))/2
+  center_long <- min(df$long) + (max(df$long) - min(df$long))/2
+  map_center <- c(lon = center_long, lat = center_lat)
+  species_map <- get_map(location = map_center, zoom = zoom, maptype = maptype)
+  ggmap(species_map) + 
+    geom_path(data = df, aes(x = long, y = lat, group=group, size=2)) + 
+    theme(legend.position="") +
+    xlab("Longitude") +
+    ylab("Latitude")
+}

man/wkt_vis.Rd

@@ -0,0 +1,27 @@
+\name{wkt_vis}
+\alias{wkt_vis}
+\title{Visualize well-known text area's on a map.}
+\usage{
+wkt_vis(x, zoom = 6, maptype = "terrain")
+}
+\arguments{
+  \item{x}{Input well-known text area (character)}
+
+  \item{zoom}{Zoom level, defaults to 6 (numeric)}
+
+  \item{maptype}{Map type, default is terrain (character)}
+}
+\description{
+This can be helpful in visualizing the area in which you
+are searching for occurrences with the \code{occ} function.
+}
+\examples{
+\dontrun{
+poly <- 'POLYGON((-111.06 38.84, -110.80 39.37, -110.20 39.17, -110.20 38.90, -110.63 38.67, -111.06 38.84))'
+wkt_vis(poly)
+
+poly2 <- 'POLYGON((-125 38.4,-125 40.9,-121.8 40.9,-121.8 38.4,-125 38.4))'
+wkt_vis(poly2)
+}
+}
+