def rad d Float(d) * Math::PI / 180.0 end def deg r Float(r) * 180.0 / Math::PI end R = 6371_000.0 def mer phi R * Math::atanh(Math::sin(phi)) end def mer_inv r Math::asin(Math::tanh(r / R)) end (0..79).each {|phi| r = mer(rad(phi)) b = deg(mer_inv(r)) printf("%4.1f %10.1f %9.5f\n", phi, r, b) }