cities {Riemann}

Data : Populated Cities in the U.S.

Description

As of January 2006, there are 60 cities in the contiguous U.S. with population size larger than 300000. We extracted information of the cities from the data delivered by maps package. Variables coord and cartesian are two identical representations of locations, which can be mutually converted by sphere.convert.

Usage

data(cities)

Format

a named list containing

names

a length-60 vector of city names.

coord

a (60\times 2) matrix of latitude and longitude.

cartesian

a (60\times 3) matrix of cartesian coordinates on the unit sphere.

population

a length-60 vector of cities' populations.

See Also

wrap.sphere

Examples

## LOAD THE DATA AND WRAP AS RIEMOBJ
data(cities)
myriem = wrap.sphere(cities$cartesian)

## COMPUTE INTRINSIC/EXTRINSIC MEANS
intmean = as.vector(riem.mean(myriem, geometry="intrinsic")$mean)
extmean = as.vector(riem.mean(myriem, geometry="extrinsic")$mean)

## CONVERT TO GEOGRAPHIC COORDINATES (Lat/Lon)
geo.int = sphere.xyz2geo(intmean)
geo.ext = sphere.xyz2geo(extmean)