# Calculating distances of lines in R

I drew some lines in a GIS application in this projection: `+proj=longlat+ellps=WGS84 +datum=WGS84` - is there a name for this projection?

I imported my lines into R and to prepare for calculating distance between points on my lines, I projected my lines using: `+proj=laea +lat_0=52 +lon_0=10 +x_0=4321000 +y_0=3210000 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs` - again, is there a name for this projection?

To actually calculate distances between points on my lines, I used the `gLength` function in the R package `rgeos`. What sort of distance calculation does `gLength` use?

`+proj=longlat +datum=WGS84` is a coordinate reference system (crs). If you would create a map with that, by treating longitude as 'x' and latitude as 'y', you could call it the equirectangular projection.
`+proj=laea` stand for "Lambert Equal Area". This is planar (Cartesian) crs (unlike angular `longlat`), and can be used with `rgeos::gLenght`. gLength computes the shortest distance, between points along the line.