[Proj] Concluding comments

[Michael P Finn]

This reminds me of something someone famous once said: ?That depends on 
what your definition of "is" is?  -- Bill Clinton

Mike Finn





"Michael Ossipoff" <mikeo2106 at msn.com> 
Sent by: proj-bounces at lists.maptools.org
08/12/2007 07:35 AM
Please respond to
"PROJ.4 and general Projections Discussions"    <proj at lists.maptools.org>


To
proj at lists.maptools.org
cc

Subject
[Proj] Concluding comments







Daan--

This is my last posting here. I?m not continuing the argument about maps. 
But I have a right to reply to some of your mis-statements and mis-quotes 
of 
me. They?ve been the constant theme of your postings, but, for brevity I?m 

mostly commenting on those in your most recent posting. You should 
understand that you are not asked or expected to reply to this.

I?d said:

Accurate directly-measured lat/long positions are a ?metric criterion? no 
less than is equal-area.

You said:

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 didn?t 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 
hadn?t 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 I?ve already replied to ?Your analysis of the issues surrounding 
your 
thesis seems to evolve as we talk?, and ?You?ve 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 I?d ?evolved to? the sinusoidal, though I?d been suggesting it from 
my 
first posting here, for when equal-area is desired. My position has been 
consistent in my postings here.

You said:

But more importantly, and back to your thesis, it's not clear to me how 
often the cartographer shares your priorities.

I reply:

Hello? If cartographers shared my priorities, about making data maps 
genuinely usable for their stated purpose, I wouldn?t have had reason to 
post my first message here. Cartographers apparently are conditioned to 
minimize distortion, often to the detriment of a map?s stated purpose.

But, then, cartographers don?t share your priorities either. You said that 

data maps should be equal area, but if you look at some atlases you?ll 
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 you?ll 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 continued:

You may want to think of a map as one that fits your notion of a "data 
map"

I reply:

Wrong. It?s 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. 
They?re that whether or not someone wants to think of them as such.

You continued:

, but people may be using it for many other purposes as well.

I reply:

By definition, spatial distribution maps tell where certain species 
ranges, 
temperature zones, etc., are. For those interested, they also show their 
relative areas. But you?re 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 you?re talking pure unsupported speculation, and 
that you don?t 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? We?ll use that to find our way back to the car, and to 
find out how far it is.? It?s good to have a bird book or a rainfall 
distribution map that shows accurate distances! :^)

You said:

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 
your arguments

I reply:

Then you?re completely lost, because it?s D. It?s D, because none of your 
theses A, B, and C accurately quote what I?d been saying. If those 
represent 
your best effort to quote what I?d been consistently saying, then you 
indeed 
are completely lost.

You said:

your jargon is idiosyncratic

I reply:

Definition of jargon:

1. Specialized language used when specialized language isn?t 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 _wasn?t_ using jargon, but was 

instead using English, the kind in standard dictionaries. Saying that 
someone isn?t using the right jargon serves the same purpose as saying 
that 
someone isn?t using the correct secret handshake or password. As I said, I 

tried to find an ica glossary of map projection terminology.

We?ve discussed how I mis-guessed the officially correct meaning of 
?equidistant?. Instead of a definition of ?equidistant?, I?d 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 I?m 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 I?d 
previously called ?equidistant
elliptical?.

Michael Ossipoff


_______________________________________________
Proj mailing list
Proj at lists.maptools.org
http://lists.maptools.org/mailman/listinfo/proj

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.maptools.org/pipermail/proj/attachments/20070813/b631ab14/attachment.html