Before revision: Definition The natural Earth is defined by the following formulas: , where x∈[ -2.7354, 2.7354 ] and y∈[ -1.4224, 1.4224 ] are the Cartesian coordinates; ∈[-, ] is the longitude from the central meridian in radians; φ∈[-/2, /2] is the latitude in radians; l(φ) is the length of the parallel at latitude φ; d(φ) is the distance of the parallel from the equator at latitude φ. l(φ) and d(φ) are given as polynomials: In the original definition of the projection, planar coordinates were lineally interpolated from a table of 19 latitudes and then multiplied by other factors.
After revision: Definition The natural Earth is defined by the following formulas: , where x∈[ -2.73539, 2.73539 ] and y∈[ -1.42239, 1.42239 ] are the Cartesian coordinates; ∈[-, ] is the longitude from the central meridian in radians; φ∈[-/2, /2] is the latitude in radians; l(φ) is the length of the parallel at latitude φ; d(φ) is the distance of the parallel from the equator at latitude φ. l(φ) and d(φ) are given as polynomials: In the original definition of the projection, planar coordinates were lineally interpolated from a table of 19 latitudes and then multiplied by other factors.