[Proj] Keep "pseudocylindirical"--with original definition. Add "cylindroid".

Michael Ossipoff mikeo2106 at msn.com
Sat Jul 5 16:11:29 EDT 2008

Dan Strebe said:

"Cylindric projections are a specialization of pseudocylindric."

...Then he said:

"There isn't enough usage out there to conclude whether "pseudocylindric" is inclusive or exclusive of "cylindric", especially given the mathematical realities of the situation."

Oh, so now we're saying that maybe cylindrical projections are _not_ psueudcylindrical, in widepread usage. Thank you. That would make a lot more sense.

This should be obvious: If the person who coined "pseudocylindrical" had intended for it to encompass "cylindrical", then s/he obviously wouldn't have chosen that word. I'm not suggesting dropping "pseudocylindrical". I'm merely suggesting not changing its meaning as a few seem to want to do.

Want a new meaning? Then how about a new word: "Cylindroid". Yes, I said that I prefer "Cylindrish", but "Cylindroid"'s use of "-oid" has more precedent.

A spere is a type of spheroid. A center is a type of centroid. And a cylindrical projection is a type of cylindroid projection.

If anyone doubts my statement about center and centroid, what do we mean when we speak of the center of a tabletop surface? We mean its area centroid. Other centroids could be calculated on the tabletop, such as the centroid of the centers of some coins placed on the table. The center of a plane or solid figure, as the term is usually used, is the area centroid or volume centroid of the figure.

So, as I said, for a cylindrical projection to be a type of cylindroid projection is well precedented and in keeping with previous usage.

And yes, "asteroid" and "trapezoid" aren't exactly like "spheroid" and "centroid" in the way that I've described. So "-oid" is used broadly, in more than one way. But, unlike with "-pseudo", there's nothing nonsensical or ridiculous, due to the meaning of "-oid", about a sphere being a kind of spheroid, a center being a kind of centroid, or a cylindrical projection being a kind of cylindroid projection.

Cylindroid projections include cylindrical and pseudocylindrical projections. 

I'm not proposing giving up "pseudocylindrical"; I'm only suggesting that it be used as intended, in its original meaning, rather than nonsensically extending it as sone would like to do.

Mike Ossipoff

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