Which projections you favor?

General discussion of map projections.
RogerOwens
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Joined: Sun Feb 02, 2014 8:24 pm

Re: Which projections you favor?

Post by RogerOwens »

Atarimaster wrote:
RogerOwens wrote:For that reason, I can say that you and Tobias have given valid good reasons why I should reject Cylindrical-Equidistant
(…)
You and Tobias stated a genuine and valid disadvantage of Cylindrical-Equidistant
(…)
Umm, my little rant was against cylindric equal-area.
Oops! I meant Cylindrical Equal-Area (CEA).
I like cylindric equidistant (as I’ve said, especially with standard parallels around 35°) – in fact, this was my favorite cylindrical projection until I learned about Patterson.
Recently you mentioned that one standard parallel that you like is a precise decimal-fraction latitude starting with 36. I'm interested in the choice of standard parallels for cylindroid maps. What was the reason for the preference for that precise value for a standard parallel?

I choose lat 30, and my 45/0 compromise (32.7651 for a cylindrical), because they make low and middle latitudes look best. For equal-area cylindricals, it's necessary to write-off the Arctic. Even Gall-Peters, grossly insulting the shapes in the tropics, still shows Svalbard as a thin horizontal line. So, for CEA, there isn't any point in even trying to make the map's Arctic useful, much less aesthetic. Hence my choice to compromise between low and middle latitudes.

Sure, CEA isn't my favorite equal-area map. Equal-Area PF8.32 is. ...along with a Behrmann/Sinusoidal graft, grafted at lat 70, or at the Arctic Circle.

But, maybe a person doesn't refer to the Arctic part of a world map as often as to other areas, and CEA has all those cylindrical advantages, for easily getting magnification and scale information (in addition to the easy position information given by pseudocylindricals) from the map, and treating all longitudes equally.

Hence my liking for CEA as a good alternative choice for an equal-area world map. I'll put up Behrmann, Equal-Area PF8.32, and the Behrmann/Sinusoidal graft on the wall.
But since in the end you say:
RogerOwens wrote: Your and Tobias' criticisms of CEA are entirely valid.
… I assume you got that and just mixed it up while typing.
It seems to me that I said that to Piotr, and so I was referring to his and your criticism of the squashing of the Arctic in CEA.

But it wasn't a typo: I meant to say that the criticisms of CEA made by both of you are entirely valid.

Of course you're both entirely right about CEA's complete botching of the Arctic. And you're right that that's a powerful argument against CEA, and a good reason to reject CEA. Yes, but there are points in favor of CEA (the advantages of cylindricals, including ease of construction and easy information-access). We state the various advantages and disadvantages, and why we value various ones as we do. And we choose based on our own valuation of those advantages, for what particular advantages we most want. So it's right to speak of advantages and disadvantages, and why we consider this or that one important...even though we each choose according to our own individual valuation of those advantages, disadvantages, and their justifications.

Michael Ossipoff
Atarimaster
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Joined: Fri Nov 07, 2014 2:43 am

Re: Which projections you favor?

Post by Atarimaster »

RogerOwens wrote:
I like cylindric equidistant (as I’ve said, especially with standard parallels around 35°) – in fact, this was my favorite cylindrical projection until I learned about Patterson.
Recently you mentioned that one standard parallel that you like is a precise decimal-fraction latitude starting with 36.
Ummmm.
You got me confused here because I thought: »I can’t remember saying something like that!«
Then I saw that you probably refer to I added the equirectangular with standard parallels at 36.5° to my website… Obviously that was a bit ambiguous: I didn’t mean that this is my favorite configuration (well, apart from the fact that it is somewhere around 35°), I merely said that I did it for a reason.
And the reason was (I didn’t mention it then, that was the ambiguous part) that in this configuration, it has the same aspect ratio as the Patterson projection. And since I devoted an entire article to Patterson, I thought it might be convenient to use the equirectangular at 36.5° for a better comparison.

RogerOwens wrote: I'm interested in the choice of standard parallels for cylindroid maps. What was the reason for the preference for that precise value for a standard parallel?
Oh, that’s simple: It’s a choice purely based on aesthetics.
In my opinion, that’s the configuration in which the equirectangular looks best.

Regards,
Tobias
Piotr
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Joined: Thu Mar 23, 2017 12:27 pm

Re: Which projections you favor?

Post by Piotr »

I can now type ¹, ², ³, ¼, ½, ¾ and ° on my keyboard!

My favorite cylindrical would have to be equidistant with standard parallels at 45°, also called Gall isographic. I even printed it and made it into a cylindrical globe.

When you hear my preferences think of Europe, not Arctic.
Piotr
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Re: Which projections you favor?

Post by Piotr »

Of course regions near map border will have to live the pain of stretching and all that. With pseudocylindrical projections, curving the meridians, especially to point pole, results in great shearing distortion, so I don't like pseudocylindrical projections. Curved parallels fix that.
Piotr
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Re: Which projections you favor?

Post by Piotr »

RogerOwens wrote:All I'm doing, when I criticize Winkel-Tripel, is suggesting to Piotr, Tobias, Dan Strebe, and anyone who happens upon this forum, that Winkel-Tripel isn't a good choice for them. So my advocacy against Winkel-Tripel is of the nature of individual advice, not complaint.
STOP SMOKING, BECAUSE THIS IS MUCH WORSE THAN A SIMPLE COMPLAINT!!!!!!!!!
RogerOwens wrote:By the way, NS/EW scale disproportion, when it's bad enough, as it is in Winkel's -30 to +30 band (comprising half of the Earth's surface), really makes nonsense of a map. Scale that's humungously, drastically, avoidably, different in two directions? The map is blatantly, unnecessarily, contradicting itself any any point where that's the case.
Fine, what you want is this:
Image
Just expect measurement errors due to the 0 to 30 band being too small.
Piotr
Posts: 313
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Re: Which projections you favor?

Post by Piotr »

Oh, one more thing you wanted is point pole. I followed your dream:
https://www.mapthematics.com/forums/vie ... 1535#p1535
Oh, you wanted no vertical distortion at low latitudes once again? No problem, I will just not squish the intermediate loximuthal horizontally, which also gives you the beloved flat Europe unlike the other method (shrinking the band vertically in Paint); here you go:
Image
Piotr
Posts: 313
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Re: Which projections you favor?

Post by Piotr »

Daan Strebe's favorite map projection seems to be Sinusoidal, as he/she uses it in the Geocart icon, and as default map projection.
daan
Site Admin
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Re: Which projections you favor?

Post by daan »

Piotr wrote:Daan Strebe's favorite map projection seems to be Sinusoidal, as he/she uses it in the Geocart icon, and as default map projection.
I have no favorite. People should be exposed to myriad projections, aspects, and configurations so that they don’t canonize any particular warped view of the world.

— daan
Piotr
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Re: Which projections you favor?

Post by Piotr »

daan wrote:
Piotr wrote:Daan Strebe's favorite map projection seems to be Sinusoidal, as he/she uses it in the Geocart icon, and as default map projection.
I have no favorite. People should be exposed to myriad projections, aspects, and configurations so that they don’t canonize any particular warped view of the world.

— daan
Then by your logic, the icon will not just have Sinusoidal, and Geocart 3 would either ask you for the map projection when a new map is made, or it will make myriad maps when a new map is made.
daan
Site Admin
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Re: Which projections you favor?

Post by daan »

Piotr wrote:Then by your logic, the icon will not just have Sinusoidal, and Geocart 3 would either ask you for the map projection when a new map is made, or it will make myriad maps when a new map is made.
That’s by your logic. I don’t recommend confusing your logic with mine. My logic for designing the human experience of a computer program differs from my logic for rationalizing my ethics of map projection education.

Cheers,
— daan
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