compress_latlon {healthyAddress}

Compress latitude and longitude to a 32-bit integer

Description

Although lat and lon are represented by doubles, this is usually slightly wasteful. This function allows you to represent coordinates as single integer, vastly reducing memory footprint.

Usage

compress_latlon(lat, lon, nThread = getOption("healthyAddress.nThread", 1L))

decompress_latlon(x, nThread = getOption("healthyAddress.nThread", 1L))

compress_latlon_general(
  lat,
  lon,
  nThread = getOption("healthyAddress.nThread", 1L)
)

decompress_latlon_general(x, nThread = getOption("healthyAddress.nThread", 1L))

Arguments

lat, lon

Coordinates to compress.

nThread

Number of threads to use.

x

An integer vector formed by one of the compression functions.

Value

The ⁠_general⁠ version of the compression/decompression use the observed range of the latitude and longitude to form a 2^16 grid, while the bare versions use the known limits of Australian address coordinates (including the overseas territories). Since, in the latter, the grid will be much less fine, you should expect greater loss of information, possibly exceeding 100 metres.

compress_latlon

An integer vector.

decompress_latlon

The original lat,lon, with some information loss

compress_latlon_general

An integer vector, with attributes minmaxLat and minmaxLon.

decompress_latlon_general

The original lat,lon, with some information loss.