4 ms·

Show HN: Interactively explore different map projections

109 points by mjmdavis 9y ago

joern 9y ago
nice, one of the best, interactive visualizations of the problems of mercator maps i've seen
m1el 9y 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/ http://healpix.jpl.nasa.gov/ [1]: https://en.wikipedia.org/wiki/Dymaxion_map https://en.wikipedia.org/wiki/Dymaxion_map
- mjmdavis 9y 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.
- mitchtbaum 9y ago
  I like Cahill-Keyes: http://www.cartotalk.com/index.php?showtopic=9406 http://www.cartotalk.com/index.php?showtopic=9406 (d3.js animation included).
- lukewtollefson 9y 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/ http://www.win.tue.nl/~vanwijk/myriahedral/ [2]: http://www.win.tue.nl/~vanwijk/myriahedral/CAJ103.pdf http://www.win.tue.nl/~vanwijk/myriahedral/CAJ103.pdf
desdiv 9y 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.
- mjmdavis 9y 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.
- 1wheel 9y ago
  It is possible, but not trivial: https://www.vis4.net/blog/posts/no-more-mercator-tiles/ 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/ https://mapzen.com/blog/escape-from-mercator/
TremendousJudge 9y 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.
- mjmdavis 9y ago
  Thank you!
MichailP 9y 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.
- mjmdavis 9y ago
  I don't yet have a very good understanding of the whole EPSG code system yet either. :s

109 points by mjmdavis 9y ago

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

m1el 9y 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/ http://healpix.jpl.nasa.gov/ [1]: https://en.wikipedia.org/wiki/Dymaxion_map https://en.wikipedia.org/wiki/Dymaxion_map

mjmdavis 9y 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.
mitchtbaum 9y ago
I like Cahill-Keyes: http://www.cartotalk.com/index.php?showtopic=9406 http://www.cartotalk.com/index.php?showtopic=9406 (d3.js animation included).
lukewtollefson 9y 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/ http://www.win.tue.nl/~vanwijk/myriahedral/ [2]: http://www.win.tue.nl/~vanwijk/myriahedral/CAJ103.pdf http://www.win.tue.nl/~vanwijk/myriahedral/CAJ103.pdf

desdiv 9y 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.

mjmdavis 9y 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.
1wheel 9y ago
It is possible, but not trivial: https://www.vis4.net/blog/posts/no-more-mercator-tiles/ 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/ https://mapzen.com/blog/escape-from-mercator/

TremendousJudge 9y 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.

mjmdavis 9y ago
Thank you!

MichailP 9y 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.

mjmdavis 9y ago
I don't yet have a very good understanding of the whole EPSG code system yet either. :s