[Proj] Poor example in general inverse procedure
Gerald I. Evenden
geraldi.evenden at gmail.com
Sun Sep 21 12:22:50 EDT 2008
Something kept bothering me with the last example in the Ipbuker-Bildirici
paper "A general algolrith for the inverse ... " using the 3x3 Jacobian for
the Newton-Raphson solution for the inverse of the Mollweide projection on
pages 180, 181. Then it finally struck me:
You do not need an iterative process at all. First, determine
t=asin(Y/sqrt(2)) (from eqn. 33)
Then you get
lambda (longitude) = X /(2*sqrt(2)*cos(t)/Pi) (from eqn. 32)
and finally:
phi (latitude) = asin(sin(2*t) + 2*t)/Pi. (from eqn. 34)
The only iterative process required is in the forward projection to solve eqn
34 for t;
--
The whole religious complexion of the modern world is due
to the absence from Jerusalem of a lunatic asylum.
-- Havelock Ellis (1859-1939) British psychologist
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