calc_zoom: Calculate a zoom given a bounding box

In dkahle/ggmap: Spatial Visualization with ggplot2

Calculate a zoom given a bounding box

Description

calc_zoom can calculate a zoom based on either (1) a data frame with longitude and latitude variables, (2) a longitude range and latitude range, or (3) a bounding box (bbox specification). The specification for (1) is identical to that of most R functions, for (2) simply put in a longitude range into lon and a latitude range into lat, and for (3) put the bounding box in for the lon argument.

Usage

calc_zoom(lon, lat, data, adjust = 0, f = 0.05)

Arguments

lon	longitude, see details
lat	latitude, see details
data	(optional) a data frame containing lon and lat as variables
adjust	number to add to the calculated zoom
f	argument to pass to make_bbox

See Also

make_bbox(), bb2bbox()

Examples

# From data
calc_zoom(lon, lat, wind)

# From range
lon_range <- extendrange( wind$lon )
lat_range <- extendrange( wind$lat )
calc_zoom(lon_range, lat_range)

# From bounding box
box <- make_bbox(lon, lat, data = crime)
calc_zoom(box)

dkahle/ggmap documentation built on March 3, 2024, 8:19 a.m.