[Proj] Concluding comments
mikeo2106 at msn.com
Sun Aug 12 08:35:13 EDT 2007
This is my last posting here. Im not continuing the argument about maps.
But I have a right to reply to some of your mis-statements and mis-quotes of
me. Theyve been the constant theme of your postings, but, for brevity Im
mostly commenting on those in your most recent posting. You should
understand that you are not asked or expected to reply to this.
Accurate directly-measured lat/long positions are a metric criterion no
less than is equal-area.
Equal-area is a rigorous concept. "Giving accurate and easy
directly-measured lat/long coordinates" is not
I comment now:
First, the word easy was not in accurate directly-measured lat/long
positions, the phrase by which I referred to a metric criterion.
Definitions should be precise, but I didnt say that accurate
directly-measured lat/long positions was a definition. It was a brief
description referring to an obvious, and obviously precisely-definable,
property of the sinusoidal.
Yes, you could say I was out of line when I referred to a property that I
hadnt defined, but, as I said, the property was obvious. But apparently not
obvious enough, and so I spelled it out for you and walked you through it,
when I defined the linearly interpolable positions property.
Though Ive already replied to Your analysis of the issues surrounding your
thesis seems to evolve as we talk, and Youve now evolved to an
interrupted sinusoidal, I want to mention those false statements again, as
examples of your overall tendency toward falsity in these postings. You said
that Id evolved to the sinusoidal, though Id been suggesting it from my
first posting here, for when equal-area is desired. My position has been
consistent in my postings here.
But more importantly, and back to your thesis, it's not clear to me how
often the cartographer shares your priorities.
Hello? If cartographers shared my priorities, about making data maps
genuinely usable for their stated purpose, I wouldnt have had reason to
post my first message here. Cartographers apparently are conditioned to
minimize distortion, often to the detriment of a maps stated purpose.
But, then, cartographers dont share your priorities either. You said that
data maps should be equal area, but if you look at some atlases youll find
many data maps that are not equal area. You said that data maps should
minimize the inaccuracy of directly-measured distances, but if you look at
some atlases youll find many data maps on projections that would definitely
not be chosen for that purpose. Oh, and did I mention that those two
requirements of yours are mutually incompatible?
You may want to think of a map as one that fits your notion of a "data map"
Wrong. Its not how I want to think of a map. The maps to which I referred
_are_ data maps, by which I said that I mean spatial distribution maps.
Theyre that whether or not someone wants to think of them as such.
, but people may be using it for many other purposes as well.
By definition, spatial distribution maps tell where certain species ranges,
temperature zones, etc., are. For those interested, they also show their
relative areas. But youre speculating that maybe there may be many other
unspecified purposes for which people use them. Let me underscore your word
may, and the fact that youre talking pure unsupported speculation, and
that you dont even specify the purposes to which you refer.
Oh yes, you did mention distance. Hey Joe, our seven and a half minute USGS
topographic map fell out of my backpack somewhere. Could you toss me that
bird book, the one with the North America maps showing where the
bird-species live? Well use that to find our way back to the car, and to
find out how far it is. Its good to have a bird book or a rainfall
distribution map that shows accurate distances! :^)
What, then, is your thesis?
You added [after describing three theses, A, B, and C, and labeling thesis D
as something else]:
If (D), then I am completely lost, and I must apologize for not following
Then youre completely lost, because its D. Its D, because none of your
theses A, B, and C accurately quote what Id been saying. If those represent
your best effort to quote what Id been consistently saying, then you indeed
are completely lost.
your jargon is idiosyncratic
Definition of jargon:
1. Specialized language used when specialized language isnt needed, and
used in order to obfuscate a topic or to impress one or more listeners.
2. Specialized language used by someone against whose statements the speaker
wants to argue.
To a large extent you probably meant that I _wasnt_ using jargon, but was
instead using English, the kind in standard dictionaries. Saying that
someone isnt using the right jargon serves the same purpose as saying that
someone isnt using the correct secret handshake or password. As I said, I
tried to find an ica glossary of map projection terminology.
Weve discussed how I mis-guessed the officially correct meaning of
equidistant. Instead of a definition of equidistant, Id only run across
definitions of three equidistant projections. Their definitions mentioned
equally-spaced parallels. So my guess was a good one, even if, unknown to
me, the official types have said that the meridians must be straight.
The projection that I called equidistant elliptical has something
important in common with equidistant cylindrical and equidistant conic:
Equally spaced parallels. Equally spaced parallels are probably the most
important and useful property of an equidistant cylindrical that makes it
different from an equal-area cylindrical. And equidistant elliptical has
that property in common with the officially-named equidistant projections.
With both projections, the equally spaced parallels greatly facilitate
determination of latitude. Maybe that means that it would be more useful to
not limit equidistant to uniform scale along straight meridians.
Maybe equidistant could be meaningfully and usefully defined in terms of
equally spaced parallels, and maybe it should be. But Im only saying that
my guess was well justified.
If, officially, equidistant maps must have straight meridians, then I have
to give the name equally-spaced elliptical to the projection that Id
previously called equidistant
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