10 Apr 2003 20:57
Re: Inverse function of a quadrant is wrong?
Clifford J Mugnier <cjmce <at> lsu.edu>
2003-04-10 18:57:11 GMT
2003-04-10 18:57:11 GMT
Gerald, If you're looking at Equivalent Spheres, an extra bit of heartburn can be garnered from a perusal of General Jean Laborde's Oblique Mercator of Madagascar. The dear general did, in fact, use a constant of integration. It only took me a week or so (MANY years ago) to duplicate that one with an HP calculator ... Cliff Mugnier LOUISIANA STATE UNIVERSITY You lost me. I can understand an animation of shifting origin but I do not understand the need for the inverse. Secondly, if the animation is more-or-less global in extent the spherical form would seem more appropriate. None of this excuses the apparent failure of PROJ.4 to do a proper inverse. This all brings me back to my recent nemesis: the Gaussian Sphere: I still have not resolved the differences between Snyder, Thomas, Pearson, Swiss Projection, Krovak and alternate stereographic. Some of these folk have elided the constants of integration and I can't figure out why and what justification was used. Are there any good mathematical cartographers out there who have been through this material? Snyder seems to use the conformal sphere as an intermediate step in the stereographic but I can' simply match the procedures(Continue reading)
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