ol_geom_circle: OpenLayers Circle Layer

In cemarks/ROpenLayers: Geo-visualization Using OperLayers and ArcGIS

OpenLayers Circle Layer

Description

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

Usage

ol_geom_circle(circle.obj, mapping = ol_aes(), name = NULL,
  df = NULL, toggle.control = FALSE, fill = "#00FF0090",
  fill.opacity = 0.5, lwd = 1, ol.lty = list(), color = "#000000",
  label = NULL, label.params = list(), tooltip = NULL,
  tooltip.params = list())

Arguments

circle.obj	matrix containing three columns: center longitude, center latitude, and radius respectively. Each row yields a single circle feature in the resulting layer.
mapping	list created by ol_aes.
name	character Layer name.
df	data.frame with same number of rows as circle.obj. Used for aestheic mapping.
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 circle 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 length nrow(circle.obj) of feature labels.
label.params, tooltip.params	named lists (e.g., list(property=value)) of label and tooltip position and format parameters. See ol_geom_polygon documentation.
tooltip	character vector of length nrow(circle.obj) of feature tooltip popups.

Details

This function stores the data required to generate an OpenLayers vector layer with features using circle geometries. See OpenLayers Circle Documentation for details.

Value

A list object of class Layer.Circle.

Aesthetics

• fill

• color

• lwd

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

See Also

ol_aes, ol_map, ol_geom_polygon

Examples

miami.circles <- matrix(
    c(
        -80.885+runif(10), #Longitudes
        25.282618+runif(10), #Latitudes
        rnorm(10,2000,500) # Radii in meters
    ),
    ncol=3
)
aesthetic.df <- data.frame(
    type=sample(c("A","B"),10,replace=TRUE),
    value=runif(10)*10
)
miami.OSM.basemap <- ol_map(
    center=c(-80.385790,25.782618),
    zoom=9
    ) +
   streetmap()
circle.layer<-ol_geom_circle(
        miami.circles,
        df = aesthetic.df,
        mapping=ol_aes(fill=type),
        lwd=2,
        name="Meaningless Miami Circles",
        toggle.control=TRUE,
        color="#000000FF",
        tooltip=sprintf("%1.2f",aesthetic.df$value)
        )
circle.fill <- ol_scale_fill_discrete(
        display=TRUE,
        preserve.opacity=TRUE
    )
circles <- miami.OSM.basemap + circle.layer + circle.fill

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

## End(Not run)

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