R: Add polygon

add_polygons {googleway}

R Documentation

Add polygon

Description

Add a polygon to a google map.

Usage

add_polygons(
  map,
  data = get_map_data(map),
  polyline = NULL,
  lat = NULL,
  lon = NULL,
  id = NULL,
  pathId = NULL,
  stroke_colour = NULL,
  stroke_weight = NULL,
  stroke_opacity = NULL,
  fill_colour = NULL,
  fill_opacity = NULL,
  info_window = NULL,
  mouse_over = NULL,
  mouse_over_group = NULL,
  draggable = NULL,
  editable = NULL,
  update_map_view = TRUE,
  layer_id = NULL,
  z_index = NULL,
  digits = 4,
  palette = NULL,
  legend = F,
  legend_options = NULL,
  load_interval = 0,
  focus_layer = FALSE
)

Arguments

`map`	a googleway map object created from `google_map()`
`data`	data frame containing at least a `polyline` column, or a `lat` and a `lon` column. If Null, the data passed into `google_map()` will be used.
`polyline`	string specifying the column of `data` containing the encoded polyline
`lat`	string specifying the column of `data` containing the 'latitude' coordinates. If left NULL, a best-guess will be made
`lon`	string specifying the column of `data` containing the 'longitude' coordinates. If left NULL, a best-guess will be made
`id`	string specifying the column containing an identifier for a shape
`pathId`	string specifying the column containing an identifer for each path that forms the complete polygon. Not required when using `polyline`, as each polyline is itself a path.
`stroke_colour`	either a string specifying the column of `data` containing the stroke colour of each shape, or a valid hexadecimal numeric HTML style to be applied to all the shapes
`stroke_weight`	either a string specifying the column of `data` containing the stroke weight of each shape, or a number indicating the width of pixels in the line to be applied to all the shapes
`stroke_opacity`	either a string specifying the column of `data` containing the stroke opacity of each shape, or a value between 0 and 1 that will be applied to all the shapes
`fill_colour`	either a string specifying the column of `data` containing the fill colour of each shape, or a valid hexadecimal numeric HTML style to be applied to all the shapes
`fill_opacity`	either a string specifying the column of `data` containing the fill opacity of each shape, or a value between 0 and 1 that will be applied to all the shapes
`info_window`	string specifying the column of data to display in an info window when a shape is clicked.
`mouse_over`	string specifying the column of data to display when the mouse rolls over the shape
`mouse_over_group`	string specifying the column of data specifying which groups of shapes to highlight on mouseover
`draggable`	string specifying the column of `data` defining if the polygon is 'draggable'. The column of data should be logical (either TRUE or FALSE)
`editable`	string specifying the column of `data` defining if the polygon is 'editable' (either TRUE or FALSE)
`update_map_view`	logical specifying if the map should re-centre according to the shapes
`layer_id`	single value specifying an id for the layer. Use this value to distinguish between shape layers for when using any `update_` function, and for separating legends.
`z_index`	single value specifying where the circles appear in the layering of the map objects. Layers with a higher `z_index` appear on top of those with a lower `z_index`. See details.
`digits`	integer. Use this parameter to specify how many digits (decimal places) should be used for the latitude / longitude coordinates.
`palette`	a function, or list of functions, that generates hex colours given a single number as an input. See details.
`legend`	either a logical indiciating if the legend(s) should be displayed, or a named list indicating which colour attributes should be included in the legend.
`legend_options`	A list of options for controlling the legend.
`load_interval`	time in miliseconds to wait between plotting each shape
`focus_layer`	logical indicating if the map should re-centre according to this layer

Details

z_index values define the order in which objects appear on the map. Those with a higher value appear on top of those with a lower value. The default order of objects is (1 being underneath all other objects)

1. Polygon
2. Rectangle
3. Polyline
4. Circle

Markers are always the top layer

palette

The palette is used to specify the colours that will map to variables. You can specify a single function to map to all variables, or a named list that specifies a separate function to map to each variable. The elements must be named either fill_colour or stroke_colour, and their values are the colour generating functions. The default is viridisLite::viridis

The legend_options can be used to control the appearance of the legend. This should be a named list, where the names are one of

position - one of c("TOP_LEFT", "TOP_CENTER", "TOP_RIGHT", "RIGHT_TOP", "RIGHT_CENTER", "RIGHT_BOTTOM", "BOTTOM_RIGHT", "BOTTOM_CENTER", "BOTTOM_LEFT", "LEFT_BOTTOM", "LEFT_CENTER", "LEFT_TOP")
css - a string of valid css for controlling the appearance of the legend
title - a string to use for the title of the legend

if legend_options are NULL, the default values will apply

If you are displaying two legends, one for stroke_colour and one for fill_colour, you can specify different options for the different colour attributes. See examples for add_circles.

Note

A polygon represents an area enclosed by a closed path. Polygon objects are similar to polylines in that they consist of a series of coordinates in an ordered sequence. Polygon objects can describe complex shapes, including

Multiple non-contiguous areas defined by a single polygon
Areas with holes in them
Intersections of one or more areas

To define a complex shape, you use a polygon with multiple paths.

To create a hole in a polygon, you need to create two paths, one inside the other. To create the hole, the coordinates of the inner path must be wound in the opposite order to those defining the outer path. For example, if the coordinates of the outer path are in clockwise order, then the inner path must be anti-clockwise.

You can represent a polygon in one of three ways

as a series of coordinates defining a path (or paths) with both an id and pathId argument that make up the polygon
as an encoded polyline using an id column to specify multiple polylines for a polygon
as a list column in a data.frame, where each row of the data.frame contains the polylines that comprise the polygon

See Examples

Examples

## Not run: 

map_key <- 'your_api_key'

## polygon with a hole - Bermuda triangle
## using one row per polygon, and a list-column of encoded polylines
pl_outer <- encode_pl(lat = c(25.774, 18.466,32.321),
      lon = c(-80.190, -66.118, -64.757))

pl_inner <- encode_pl(lat = c(28.745, 29.570, 27.339),
       lon = c(-70.579, -67.514, -66.668))

df <- data.frame(id = c(1, 1),
       polyline = c(pl_outer, pl_inner),
       stringsAsFactors = FALSE)

df <- aggregate(polyline ~ id, data = df, list)

google_map(key = map_key, height = 800) %>%
    add_polygons(data = df, polyline = "polyline")

## the same polygon, but using an 'id' to specify the polygon
df <- data.frame(id = c(1,1),
       polyline = c(pl_outer, pl_inner),
       stringsAsFactors = FALSE)

google_map(key = map_key, height = 800) %>%
    add_polygons(data = df, polyline = "polyline", id = "id")

## the same polygon, specified using coordinates, and with a second independent
## polygon
df <- data.frame(myId = c(1,1,1,1,1,1,2,2,2),
      lineId = c(1,1,1,2,2,2,1,1,1),
      lat = c(26.774, 18.466, 32.321, 28.745, 29.570, 27.339, 22, 23, 22),
      lon = c(-80.190, -66.118, -64.757, -70.579, -67.514, -66.668, -50, -49, -51),
      colour = c(rep("#00FF0F", 6), rep("#FF00FF", 3)),
      stringsAsFactors = FALSE)

google_map(key = map_key) %>%
  add_polygons(data = df, lat = 'lat', lon = 'lon', id = 'myId', pathId = 'lineId',
               fill_colour = 'colour')




## End(Not run)

[Package googleway version 2.7.8 Index]