meters.per.degree.lat: Convert degrees latitude to meters North-South.

In ejanalysis/proxistat: Create a Proximity Score in Each Census Unit, Based on Distances to Specified Points (as in EPA's EJScreen tool, for example)

Convert degrees latitude to meters North-South.

Description

meters.per.degree.lat returns meters traveled North-South per decimal degrees latitude, given latitude (Northern Hemisphere).

Usage

meters.per.degree.lat(theta)

Arguments

theta

The decimal degrees of latitude of the Northern Hemisphere location(s) of interest, as number or vector of numbers.

Details

This function returns the meters traveled North-South per decimal degree latitude, at a given latitude (Northern Hemisphere). This is an approximation and is less accurate further from the given latitude. Based on http://en.wikipedia.org/wiki/Latitude#Length_of_a_degree_of_latitude and
http://en.wikipedia.org/wiki/Longitude#Length_of_a_degree_of_longitude
Input theta is latitude on WGS84.
Also see http://en.wikipedia.org/wiki/Longitude and http://en.wikipedia.org/wiki/Decimal_degrees

Value

Returns meters traveled N-S, as a number or vector of numbers the same length as the input.

See Also

meters.per.degree.lon for a similar function but for travel East-West, with more detailed explanation/help, and get.distances.all and get.distances for distances between points, and related functions.

Examples

meters.per.degree.lat(32)
meters.per.degree.lat(c(0,45,72))

ejanalysis/proxistat documentation built on April 2, 2024, 10:13 a.m.