From 94e36270ca393bd7b107bf690f09fd8ec1cd046b Mon Sep 17 00:00:00 2001 From: Charles Karney Date: Tue, 27 Oct 2020 10:02:27 -0400 Subject: Use nm units in builtins.gie. Remove backward looking comments in code. --- src/tsfn.cpp | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/tsfn.cpp') diff --git a/src/tsfn.cpp b/src/tsfn.cpp index a0960a66..8ed258d6 100644 --- a/src/tsfn.cpp +++ b/src/tsfn.cpp @@ -11,10 +11,13 @@ double pj_tsfn(double phi, double sinphi, double e) { * e = eccentricity of the ellipsoid (dimensionless) * Output: * ts = exp(-psi) where psi is the isometric latitude (dimensionless) + * = 1 / (tan(chi) + sec(chi)) * Here isometric latitude is defined by * psi = log( tan(pi/4 + phi/2) * * ( (1 - e*sin(phi)) / (1 + e*sin(phi)) )^(e/2) ) * = asinh(tan(phi)) - e * atanh(e * sin(phi)) + * = asinh(tan(chi)) + * chi = conformal latitude ***************************************************************************/ double cosphi = cos(phi); -- cgit v1.2.3