mercator
Determine the Mercator scale factor for a given latitude. At the equator the scale factor will be 1, which increases at higher latitudes. https://en.wikipedia.org/wiki/Mercator_projection#Scale_factor
Parameters
lat
Determine the Mercator scale factor for a given latitude. At the equator the scale factor will be 1, which increases at higher latitudes. https://en.wikipedia.org/wiki/Mercator_projection#Scale_factor