49 50 Ver6.09.hp Geodesic distance & Earth Euclidean distance calculator, bearing

[Gil]

Version 2.9

Changed the subprogram lat—> to calculate the radius from Earth centre to the given surface latitude.

It was already correct, but, for special latitude = +/-90 (at the poles), it did not give the expected exact radius b =6356752.31425,
but 6356752.3142, due to roundings in the formulae. The same occurred with latitude = 0 (at equator line), reckoned 6378137.0001 in the program, instead of the true value of the radius a = 6378137.

Here are the codes
for lat—>:
\<< "1 single Argument:

lat
 in D.mmss

To 
change a, b, INV.f


run
 before all 
C.abf

" DROP DEG DUP 'lat' STO HMS\-> \-> la
\<<
IF la 0 \=/
THEN
IF la ABS 90 \=/
THEN '\v/(((a^2*COS(la))^2+(b^2*SIN(la))^2)/((a*COS(la))^2+(b*SIN(la))^2))' \->NUM
ELSE b
END
ELSE a
END "R Centre-Earth(" lat + ")" + \->TAG 'b/a*TAN(la)' \->NUM ATAN COS a * 2 * \pi * \->NUM "Circumf(" lat + ")" + \->TAG
\>>
\>>

As usual here is attached the full Directory with all the programs and variables.

Regards,
Gil Campart