ol_scale_iconimage_discrete: Icon Image Scale

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

Icon Image Scale

Description

Map icon images to discrete variable values.

Usage

ol_scale_iconimage_discrete(icon.img.vector = NULL, name = NULL,
  na.img.src = NULL, ordered.values = NULL, display = FALSE,
  icon.width = NULL)

Arguments

icon.img.vector	character named vector of the form c(value=image.path). If NULL, a default mapping is assigned to the images available in the layer.
name	character the scale name.
na.img.src	character image path assigned to unrecognized or NA values.
ordered.values	character, numeric, or factor vector giving the ordering for the legend display. If NULL, the ordering from icon.img.vector is used.
display	logical indicating whether to draw the scale for output in the HTML. If TRUE, a bitmap will be created and sourced in the HTML in one or more img tags.
icon.width	numeric width(s) of icons for the legend display only. Icon widths for the map overlay are defined in ol_geom_icon.

Details

This method maps OpenLayers point (icon) feature images to discrete variable values. This scale can be added to an Ol.Map S3 object only if the Ol.Map object has a layer with an "iconimage" mapping to a numeric, character, or factor variable. If no such layer exists, attempts to add this type of scale will result in a warning.

Value

list of class Scale.IconImage.Discrete.

See Also

ol_map, ol_geom_icon,

Examples

freebsd.icon <- "https://www.freebsd.org/gifs/daemon-phk.png"
freebsd.icon.width <- 191
r.icon <- "https://www.r-project.org/Rlogo.png"
r.icon.width <- 200
loc.df <- data.frame(
    lon=c(
        -73.953,
        -78.938,
        -74.007
    ),
    lat=c(
        40.768,
        36.001,
        40.708
    ),
    type=c(
        "R",
        "R",
        "BSD"
    )

)
icon.map <- ol_map(
    center=c(-75,38),
    zoom=5
) + 
    streetmap()+
    ol_geom_icon(
        loc.df[,1:2],
        c(r.icon,freebsd.icon),
        mapping=ol_aes(iconimage=type),
        df = loc.df,
        name="Some Open Source Locations",
        icon.size.scalar='autoscale',
        src.img.width=c(r.icon.width,freebsd.icon.width),
        toggle.control=TRUE
) +
    ol_scale_iconimage_discrete(
    c(R=r.icon,BSD=freebsd.icon),
    display=TRUE
)
## Not run: 
# Oave as HTML and open in browser
ol_map2HTML(
  icon.map,
  'servers.html'
)
browseURL("servers.html")

## End(Not run)

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