ol_geom_polygon: OpenLayers Polygon Layer
In cemarks/ROpenLayers: Geo-visualization Using OperLayers and ArcGIS

ol_geom_polygon

R Documentation

OpenLayers Polygon Layer

Description

Function to create a polygon layer to add to an OpenLayers Map object.

Usage

ol_geom_polygon(polygon.obj, mapping = ol_aes(), name = NULL,
  df = NULL, toggle.control = FALSE, fill = "#00FF00",
  fill.opacity = 0.5, lwd = 1, ol.lty = list(), color = "#000000",
  label = NULL, label.params = list(), tooltip = NULL,
  tooltip.params = list())

Arguments

`polygon.obj`	SpatialPolygonsDataFrame, SpatialPolygons, list of polygon-like objects, or a two-column matrix of longitude-latitude coordinates to be used as ordered polygon vertices.
`mapping`	list created by ol_aes.
`name`	character Layer name.
`df`	data.frame with same number of polygon objects as `polygon.obj`. Used for aestheic mapping. Defaults to polygon.obj@data if `class(polygon.obj)==SpatialPolygonsDataFrame)` and df is not provided.
`toggle.control`	logical indicating whether this layer will have a visibility toggle.
`fill`	character color string, or vector of color strings. Used only if no `fill` aesthetic is provided in `mapping`
`fill.opacity`	numeric in [0,1]. Controls circle opacity if no opacity provided in `fill` or `fill` aesthetic.
`lwd`	numeric polygon border width. Used only if no `lwd` aesthetic is provided in `mapping`
`ol.lty`	(experimental) numeric vector with length > 1, or `list` of such vectors. Used only if no `ol.lty` aesthetic is provided in `mapping`. See OpenLayers ol/style/Stroke Documentation, 'lineDash' property for more information.
`color`	character border color string, or vector of color strings. Used only if no `color` aesthetic is provided in `mapping`
`label`	character vector of polygon feature labels.
`label.params`	named list (e.g., `list(property=value)`) of label position and format parameters. See below.
`tooltip`	character vector polygon feature tooltip popups.
`tooltip.params`	named list (e.g., `list(property=value)`) of tooltip position and format parameters. See below.

Details

This function creates a list object containing the data required to generate an OpenLayers vector layer with features using MultiPolygon. See OpenLayers MultiPolygon Documentation for details.

Value

A list object of class Layer.SpatialPolygon.

Aesthetics

fill
color
lwd
ol_lty (experimental; See OpenLayers ol/style/Stroke Documentation, 'lineDash' property for more information.)

Formatting Labels With `label.params`

The label.params parameter provide direct access to OpenLayers feature text styling (see OpenLayers Documentation). Multiple values for any of these properties is not supported. The following ol/style/Text properties are supported:

`font`	character label font CSS string
`offsetX`	numeric label x-offset
`offsetY`	numeric label y-offset
`rotation`	numeric label rotation
`textAlign`	character label text horizontal alighment
`textBaseline`	character label text vertical alignment
`stroke_color`	character text color
`fill_color`	character text fill color

Formatting Tooltips With `label.params`

The tooltip.params parameter enable the user to control tooltip formats. Unlike the label.params, not all tooltip.params are embedded in Openlayers javascript objects; some are translated to corresponding CSS properties. The table below provides a list of supported properties and their descriptions. OpenLayers Overlay Documentation provides additional information about Overlay Properties.

`font`	character tootltip CSS font
`offsetX`	numeric OpenLayers Overlay x-offset
`offsetY`	numeric OpenLayers Overlay y-offset
`positioning`	character OpenLayers Overlay positioning string
`stroke_color`	character Tooltip CSS font-color
`fill_color` character	Tooltip CSS background-color
`padding`,	character Tooltip CSS padding
`border`,	character Tooltip CSS border
`borderradius` character	Tooltip CSS border-radius

Examples

polygon.matrix1 <- matrix(
    c(
        -80.385+c(0,0.05,0.05,0,0),
        25.782618+c(0,0,0.05,0.05,0)
    ),
    ncol=2
)
polygon.matrix2 <- matrix(
    c(
        -80.34+c(0,0.05,0.025,0),
        25.73++c(0,0,0.025*sqrt(3),0)
    ),
    ncol=2
)
polygon.list<-list(polygon.matrix1,polygon.matrix2)
polygon.df <- data.frame(shape=c("rectangle","triangle"),no=c(1,2))
miami.OSM.basemap <- ol_map(
    center=c(-80.385790,25.782618),
    zoom=9
    ) + 
   streetmap() 
polygon.layer <- ol_geom_polygon(
    polygon.list,
    mapping=ol_aes(
        fill=shape,
    ),
    df=polygon.df,
    lwd=1,
    name="Miami Polygons",
    toggle.control=TRUE,
    tooltip=polygon.df$no
)
polygon.fill.scale <- ol_scale_fill_discrete(display=TRUE)
polygons.over.miami <- miami.OSM.basemap + 
    polygon.layer + 
    polygon.fill.scale

## Not run: 
# Output to file and view
ol_map2HTML(
  polygons.over.miami,
  'miami_polygons.html',
  map.heading="Miami Shapes",
  map.note="Note: Mouseover popup values are 
    independent of shape size &amp; color."
)
browseURL("miami_polygons.html")

## End(Not run)

cemarks/ROpenLayers documentation built on March 31, 2022, 12:05 p.m.