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Show HN: Interactively explore different map projections (opens in new tab)

mjmdavis.com

109 pointsmjmdavis8y ago12 comments

12 comments

m1el8y ago

There's a few map projections I really like that don't have most of these problems: HELAPIx[0] and Dymaxion map[1].

HELAPIx is designed to have pixels of the same area, and Dymaxion is designed to have the least distortion.

[0]: http://healpix.jpl.nasa.gov/

[1]: https://en.wikipedia.org/wiki/Dymaxion_map

lukewtollefson8y ago

Probably my favorite are the Myriahedral projections[1], basically the Dymaxion map, but with ridiculous number of faces. In his paper he also unfolds a fractal[2].

[1]: http://www.win.tue.nl/~vanwijk/myriahedral/

[2]: http://www.win.tue.nl/~vanwijk/myriahedral/CAJ103.pdf

mitchtbaum8y ago

I like Cahill-Keyes: http://www.cartotalk.com/index.php?showtopic=9406 (d3.js animation included).

mjmdavisOP8y ago

I think Healpix is included in the tool at the bottom. Also check out the last few in the list which are similar to Dymaxion.

desdiv8y ago

Are there any online maps that aren't Web Mercator? Google Maps, Here.com, OpenStreetMap, Bing Maps, MapQuest are all Mercator-only, with no easy option to switch.

mjmdavisOP8y ago

One of the main reasons it's so popular is that is preserves shape, angle and north is always up. This means you can create a tiling map server and use the same tiles at all scales.

1wheel8y ago

It is possible, but not trivial:

https://www.vis4.net/blog/posts/no-more-mercator-tiles/ (comments are also informative, particularly Tom MacWright's)

https://mapzen.com/blog/escape-from-mercator/

MichailP8y ago

Is there some nice explanation of how the projections between various EPSG codes work? I converted one projection into another but in QGIS or in python pyproj, but except for the very basics I have no idea what is going on.

mjmdavisOP8y ago

I don't yet have a very good understanding of the whole EPSG code system yet either. :s

joern8y ago

nice, one of the best, interactive visualizations of the problems of mercator maps i've seen

TremendousJudge8y ago

typo:

>To remedy the horizontal stretching, the Mercator Projection stretches the globe out in the vertical direction an equal amount to the stretching in the vertical direction.

mjmdavisOP8y ago

Thank you!

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12 comments

m1el8y ago

There's a few map projections I really like that don't have most of these problems: HELAPIx[0] and Dymaxion map[1].

HELAPIx is designed to have pixels of the same area, and Dymaxion is designed to have the least distortion.

[0]: http://healpix.jpl.nasa.gov/

[1]: https://en.wikipedia.org/wiki/Dymaxion_map

lukewtollefson8y ago

Probably my favorite are the Myriahedral projections[1], basically the Dymaxion map, but with ridiculous number of faces. In his paper he also unfolds a fractal[2].

[1]: http://www.win.tue.nl/~vanwijk/myriahedral/

[2]: http://www.win.tue.nl/~vanwijk/myriahedral/CAJ103.pdf

mitchtbaum8y ago

I like Cahill-Keyes: http://www.cartotalk.com/index.php?showtopic=9406 (d3.js animation included).

mjmdavisOP8y ago

I think Healpix is included in the tool at the bottom. Also check out the last few in the list which are similar to Dymaxion.

desdiv8y ago

Are there any online maps that aren't Web Mercator? Google Maps, Here.com, OpenStreetMap, Bing Maps, MapQuest are all Mercator-only, with no easy option to switch.

mjmdavisOP8y ago

One of the main reasons it's so popular is that is preserves shape, angle and north is always up. This means you can create a tiling map server and use the same tiles at all scales.

1wheel8y ago

It is possible, but not trivial:

https://www.vis4.net/blog/posts/no-more-mercator-tiles/ (comments are also informative, particularly Tom MacWright's)

https://mapzen.com/blog/escape-from-mercator/

MichailP8y ago

mjmdavisOP8y ago

I don't yet have a very good understanding of the whole EPSG code system yet either. :s

joern8y ago

nice, one of the best, interactive visualizations of the problems of mercator maps i've seen

TremendousJudge8y ago

typo:

>To remedy the horizontal stretching, the Mercator Projection stretches the globe out in the vertical direction an equal amount to the stretching in the vertical direction.

mjmdavisOP8y ago

Thank you!

j / k navigate · click thread line to collapse