[Proj] Re: Transverse or oblique width-adjusted Aitoff or Hammer-Aitoff for oblong regions

Michael Ossipoff mikeo2106 at msn.com
Thu Jul 17 13:32:39 EDT 2008

I'd said:
> > As I've said before, I suggest that, for general purpose maps of countries> > or states, equal area is a poor choice.
Gerald said:
> Of all the statements you have made, that one most clearly demonstrates that > you are either a troll and/or otherwise do not have a clue about cartography.
Gerald, you don't support your statements very well. Presumably you disagree with what I said, but we won't know why you disagree unless you tell us.
A general purpose map, like anything designated "general purpose", doesn't have a specific task. In particular, a general purpose map isn't particularly needed or intended to show area relationships. It isn't a data map intended to show you the areas of climate zones or species habitat ranges. It isn't a land-use map intended to show you how much land is used for growing wheat and how much is used for raising cattle. It's a general purpose map without any such specific intended purpose.
The most often-measured quantity on a map is distance. The accuracy with which you can measure distance directly on a map is limited by something known as "scale variation". An equal area map has about twice the percentage scale variation of a similar non-equal-area map. Equal-area doubles the percentage scale variation. That means that it doubles the percentatge by which your measurement can be off when you measure a distance on the map.
Gerald, that is your third message to me. All three of your messages have been virtually identical. You make angry noises without saying anything with objective meaning, and without justifying the angry feelings that you seem to need to express. This behavior of yours has no place on a discussion list. Maybe you can get help.
Mike Ossipoff
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