Type: Package
Title: Open Location Code Handling in R
Version: 0.3.0
Date: 2016-05-07
Author: Oliver Keyes
Maintainer: Oliver Keyes <ironholds@gmail.com>
Description: 'Open Location Codes' http://openlocationcode.com/ are a Google-created standard for identifying geographic locations. 'olctools' provides utilities for validating, encoding and decoding entries that follow this standard.
License: MIT + file LICENSE
Suggests: testthat, knitr
LinkingTo: Rcpp
Imports: Rcpp
VignetteBuilder: knitr
RoxygenNote: 5.0.1
URL: https://github.com/Ironholds/olctools
BugReports: https://github.com/ironholds/olctools/issues
NeedsCompilation: yes
Packaged: 2016-05-08 23:21:34 UTC; ironholds
Repository: CRAN
Date/Publication: 2016-05-09 06:25:08

Tools for handling Open Location Codes

Description

Open Location Codes are a Google-created standard for identifying geographic locations. olctools provides utilities for validating, encoding and decoding entries that follow this standard.

Decode Open Location Codes into Latitude and Longitude Pairs

Description

decode_olc takes Open Location Codes and, if they're valid (see validate_full) returns the minium, centred and maximum latitude and longitude for those coordinates.

Usage

decode_olc(olcs)

Arguments

olcs

a vector of Open Location Codes, generated through encode_olc or an equivalent tool.

See Also

encode_olc for the opposite operation, and shorten_olc to convert "full" Open Location Codes to "short" Open Location Codes.

Examples

decode_olc("7FG49Q00+")

Encode Latitude and Longitude Pairs as Open Location Codes

Description

encode_olc creates Open Location Codes from latitude and longitude values, of a specified length.

Usage

encode_olc(lats, longs, length)

Arguments

lats

a numeric vector of latitudes.

longs

a numeric vector of longitudes, equivalent in size to lats

length

the length you want the resulting OLCs to be. The conventional lengths are 10 or 11, with any number above 8 and any even number below it being acceptable. length should consist of either a single value, if you want all codes to be calculated to the same length, or a vector of values the same size as lats and longs if you want to pre-set values.

See Also

decode_olc for the opposite operation, and shorten_olc to convert "full" Open Location Codes to "short" Open Location Codes.

Examples

encode_olc(20.375, 2.775,6)

Recover Full Open Location Codes From Shortened Codes

Description

shorten_olc (and other sources) shorten a code, reducing the space it occupies. They also limit its ability to be translated back into latitude/longitude pairs. recover_olc recovers a full code from a shortened one, allowing it to be decoded with decode_olc. Some loss of accuracy or precision is expected - and as it finds the closest match to the coordinates rather than to the original code, the characters may be very different.

Usage

recover_olc(olcs, lats, longs)

Arguments

olcs

a vector of short open location codes, generated with shorten_olc or through any other means.

lats

a numeric vector of latitudes.

longs

a numeric vector of longitudes, equivalent in size to lats.

Examples

# Shorten an OLC and then recover the nearest full code. Note the actual characters differ.
shortened_code <- shorten_olc("8FVC9G8F+6X", 47.5, 8.5);
recovered_code <- recover_olc(shortened_code, 47.4, 8.6);

Shorten Full Open Location Codes

Description

One of the things that makes OLCs useful is that they can shortened - you can trim characters off them, saving space without substantially compromising the accuracy. shorten_olc takes full-length OLCs (generated with encode_olc or any other way) and shortens them.

Usage

shorten_olc(olcs, lats, longs)

Arguments

olcs

a vector of open location codes, generated with encode_olc or through any other means.

lats

a numeric vector of latitudes.

longs

a numeric vector of longitudes, equivalent in size to lats.

See Also

encode_olc to create full Open Location Codes.

Examples

#Encode an OLC and then shorten it
olc <- encode_olc(51.3708675,-1.217765625, 12)
validate_full(olc)
# [1] TRUE

olc <- shorten_olc(olc, 51.3708675,-1.217765625)
validate_short(olc)
# [1] TRUE

Check the Validity of Open Location Codes

Description

These functions allow a useR to check whether OLCs they've been provided are valid or not. valid_short identifies whether a vector of OLCs are valid "short" codes; valid_long identifies whether OLCs are valid "long" codes, and valid_full identifies whether OLCs are valid, full stop.

Usage

validate_olc(codes)

validate_short(codes)

validate_full(codes)

Arguments

codes

a character vector containing Open Location Codes.

Value

a vector of TRUE and FALSE values, where TRUE corresponds to a valid code and FALSE an invalid.

See Also

decode_olc and encode_olc for creating and resolving valid Open Location Codes.

Examples

#Validate that a particular OLC is valid
validate_olc("WC2345+G6g")
#[1] TRUE

#It is! Is it a short?
validate_short("WC2345+G6g")
#[1] TRUE
#Yep!

#So it's not full?
validate_full("WC2345+G6g")
#[1] FALSE
#Nope!