Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

file 78 lines (62 sloc) 2.678 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78
GeomPolygon <- proto(Geom, {
  draw <- function(., data, scales, coordinates, ...) {
    n <- nrow(data)
    if (n == 1) return()
    
    ggname(.$my_name(), gTree(children=gList(
      with(coordinates$munch(data, scales),
        polygonGrob(x, y, default.units="native",
        gp=gpar(col=colour, fill=alpha(fill, alpha), lwd=size * .pt,
         linetype=linetype))
      )
      #GeomPath$draw(data, scales, coordinates)
    )))
  }

  objname <- "polygon"
  desc <- "Polygon, a filled path"
  icon <- function(.) polygonGrob(c(0.1, 0.4, 0.7, 0.9, 0.6, 0.3), c(0.5, 0.8, 0.9, 0.4, 0.2, 0.3), gp=gpar(fill="grey20", col=NA))
  
  default_stat <- function(.) StatIdentity
  default_aes <- function(.) aes(colour="NA", fill="grey20", size=0.5, linetype=1, alpha = 1)
  required_aes <- c("x", "y")
  guide_geom <- function(.) "polygon"

  draw_legend <- function(., data, ...) {
    data <- aesdefaults(data, .$default_aes(), list(...))
  
    with(data, grobTree(
      rectGrob(gp = gpar(col = colour, fill = alpha(fill, alpha), lty = linetype)),
      linesGrob(gp = gpar(col = colour, lwd = size * .pt, lineend="butt", lty = linetype))
    ))
  }

  seealso <- list(
    geom_path = "an unfilled polygon",
    geom_ribbon = "a polygon anchored on the x-axis"
  )
  
  examples <- function(.) {
    # When using geom_polygon, you will typically need two data frames:
    # one contains the coordinates of each polygon (positions), and the
    # other the values associated with each polygon (values). An id
    # variable links the two together

    ids <- factor(c("1.1", "2.1", "1.2", "2.2", "1.3", "2.3"))

    values <- data.frame(
      id = ids,
      value = c(3, 3.1, 3.1, 3.2, 3.15, 3.5)
    )

    positions <- data.frame(
      id = rep(ids, each = 4),
      x = c(2, 1, 1.1, 2.2, 1, 0, 0.3, 1.1, 2.2, 1.1, 1.2, 2.5, 1.1, 0.3,
      0.5, 1.2, 2.5, 1.2, 1.3, 2.7, 1.2, 0.5, 0.6, 1.3),
      y = c(-0.5, 0, 1, 0.5, 0, 0.5, 1.5, 1, 0.5, 1, 2.1, 1.7, 1, 1.5,
      2.2, 2.1, 1.7, 2.1, 3.2, 2.8, 2.1, 2.2, 3.3, 3.2)
    )
    
    # Currently we need to manually merge the two together
    datapoly <- merge(values, positions, by=c("id"))

    (p <- ggplot(datapoly, aes(x=x, y=y)) + geom_polygon(aes(fill=value, group=id)))

    # Which seems like a lot of work, but then it's easy to add on
    # other features in this coordinate system, e.g.:

    stream <- data.frame(
      x = cumsum(runif(50, max = 0.1)),
      y = cumsum(runif(50,max = 0.1))
    )

    p + geom_line(data = stream, colour="grey30", size = 5)
    
    # And if the positions are in longitude and latitude, you can use
    # coord_map to produce different map projections.
  }
})
Something went wrong with that request. Please try again.