[Proj] Re: Linear projections reply

strebe strebe at aol.com
Sun Jun 29 19:24:32 EDT 2008

Mr. Ossipoff:

Assuming you had some reason for posting your work, I briefly noted how your work fits in with standard definitions and mathematical formulations. Whether it "goes without saying" that there is no limit to the number of "linear" projections depends upon the reader. Perhaps it goes without saying for you. I'm at a loss to know why I would know that or why you might suppose the same must apply to every reader. In general I do not see the benefit of explaining that you already know something unless someone clearly implies that you do not.

Cylindric projections are a specialization of pseudocylindric. Whether it is incorrect to call a cylindric projection "pseudocylindric" is something best left to those of uselessly pedantic temperament.

-- daan Strebe

On Jun 29, 2008, at 1:15:09 PM, "Michael Ossipoff" <mikeo2106 at msn.com> wrote:
Strebe wrote:

> In other words, 
> a "linear" projection is a pseudocylindric projection with equally spaced parallels.

Yes, and, for maps, I like the term "linear", because of its one-word brevity, and because it directly refers to such maps' big advantage.

For that statement about "linear projection" meaning "pseudocylindrical projection with equally-spaced parallels", to be true, then "pseudocylindrical projections" must include "cylindrical projections". But "pseudo-" means "similar to, but not...". So, if cylindrical projections are considered a subset of pseudocylindrical projections, then surely pseudocylindrical projections need another name. Isn't naming and proposing terminology one of the purposes of your organization?

> There is no limit to how many such projections could be created. 

Yes, and I never meant to imply that my list of "some linear projections" covered all of them. Surely it goes without saying that an infinite number of linear projections could be defined.

As for the mathematical information in your letter, my computer won't display it. The screen just shows spurious characters. To make it worse, the misrepresentation of the characters doesn't even seem to be consistent.

Could the mathematics that you posted by written in ordinary plain text characters?

Surely you aren't just saying that Y varies linearly with latitude and X varies linearly with longitude, because that was my definition. If your posting tells of something interesting or curious about linear projections that I didn't know, then I regrettably miss out on being able to display the information on this computer.

Mike Ossipoff

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