Show HN: Interactively explore different map projections

Show HN: Interactively explore different map projections(mjmdavis.com)

109 points by mjmdavis 9 years ago | 12 comments

m1el 9 years 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.

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

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

mitchtbaum 9 years ago | |

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

mjmdavis 9 years 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.

desdiv 9 years 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 9 years 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 9 years 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/

MichailP 9 years 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 9 years ago | |

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

joern 9 years ago |

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

TremendousJudge 9 years 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 9 years ago | |

Thank you!