autolegend {autoimage}

Add legend to projected image.

Description

autolegend adds a color scale to the current device based on the information from the last calls to the autolayout and pimage functions.

Usage

autolegend()

Details

Internally, autolegend calls the .legend.scale.args, .legend.horizontal, and .legend.mar functions to obtain the relevant information.

See Also

autolayout, pimage, legend.scale

Examples

data(narccap)
autolayout(c(1, 1), legend = "h")
pimage(lon, lat, tasmax[,,1], legend = "none")
autolegend()

# common legend with distinct lines
autolayout(c(1, 2), legend = "h")
pimage(lon, lat, tasmax[,,1], legend = "none", map = "world")
pimage(lon, lat, tasmax[,,2], legend = "none", map = "usa", 
       proj = "bonne", parameters = 40)
autolegend()

# separate legends with distinct lines
autolayout(c(1, 2), legend = "v", common.legend = FALSE)
pimage(lon, lat, tasmax[,,1], legend = "none", map = "state",
       proj = "bonne", parameters = 40, axes = FALSE)
autolegend()
pimage(lon, lat, tasmax[,,2], legend = "none", map = "usa", 
       proj = "albers", parameters = c(32, 45), axes = FALSE)
autolegend()

data(worldMapEnv, package = "maps")
# extract hawaii and alaskan borders
hiak <- maps::map("world", c("USA:Hawaii", "USA:Alaska"), 
                  plot = FALSE)
# extract colorado cities from us.cities
data(us.cities, package = "maps")
codf <- us.cities[us.cities$country.etc == "CO", ]
# select smaller subset of colorado cities
codf <- codf[c(3, 5, 7:11, 15, 18), ]
# extract capitals from us.cities
capdf <- us.cities[us.cities$capital == 2,]

# setup plotting area
autolayout(c(1, 2), legend = "h", common.legend = FALSE, outer = TRUE)
# create image of NARCCAP data.
# xlim is chosen so to include alaska and hawaii
# add grey state borders
pimage(lon, lat, tasmax[,,1], legend = "none", proj = "mercator",
       map = "state", xlim = c(-180, 20), 
       lines.args = list(col = "grey"))
# add hawaii and alaskan borders
plines(hiak, proj = "mercator", col = "grey")
# add state captials to image
ppoints(capdf$lon, capdf$lat, proj = "mercator", pch = 16)
# title image
title("tasmax for North America")
# add legend for plot
autolegend()
# load colorado geochemical data
data(co, package = "gear")
# create image for colorado aluminum measurements
# use bonne projection
# customize legend colors
# add grey county borders
pimage(co$lon, co$lat, co$Al, map = "county", legend = "none",
       proj = "bonne", parameters = 39, 
       paxes.args = list(grid = FALSE),
       col = fields::tim.colors(64), 
       lines.args = list(col = "grey"))
# add colorado city points to image
ppoints(codf$lon, codf$lat, pch = 16, proj = "bonne")
# add names of colorado cities to image
ptext(codf$lon, codf$lat, labels = codf$name, proj = "bonne", pos = 4)
# title plot
title("Colorado Aluminum levels (%)")
# add legend to current image
autolegend()
# add common title for plots
mtext("Two complicated maps", col = "purple", outer = TRUE, cex = 2)

reset.par() # reset device default