Mapper 1.0 - A tiny geo coordinate converter - basically for plotting latitude/longitude pairs to an image

Installation

• gem install mapper

Usage

• require 'mapper'
• # now just initialize it with two known points on your map and you are ready to go!
• mapper = Mapper.new({:lat=>48.13,:lon=>11.57,:x=>278,:y=>503}, {:lat=>53.55,:lon=>9.99,:x=>206,:y=>114})
• mapper.add_point(:lat=>52.52, :lon=>13.41)
• mapper.add_point(:x=>136, :y=>410)
• mapper.each_point{|point| p point}
• -> {:lat=>52.52, :lon=>13.41, :x=>361.848101265823, :y=>187.924354243542}
• -> {:lat=>49.4257840616967, :lon=>8.45388888888889, :x=>136, :y=>410}

Notes

• Mapper assumes your map is in the mercator projection! (http://en.wikipedia.org/wiki/Mercator_projection)
• Luckily a lot of maps are: GoogleMaps, OpenStreetMap, ... :)
• Mapper is NOT a high precision tool! But in most cases it should be just okay enough.