[GIP]

Nov. 19th, 2023 09:02 am
jazzfish: a 5000km circle centered on Paris, on a Mercator projection (stupid Mercator)
[personal profile] jazzfish
The worst things about mapping:
  • Degrees/minutes/seconds. If you can use metric measurements you can use decimal degrees LIKE A NORMAL PERSON. Bonus: my calculator (recommended by Scott the instructor) will convert freely between decimal degrees for calculation and DMS for final answers... but it only gives seconds to one decimal place and Scott wants two. So I still have to do the "subtract the integer, multiply by sixty" dance.
  • Coordinates are given north-first, east-second, in violation of all the math I have learned since I started learning Cartesian coordinates in sixth grade. Arguably this one is Descartes's fault and he should have put X as up and Y as right so it would line up with the existing use-case.
  • Relatedly, azimuths start from north and go clockwise, while polar coordinates start from the x-axis and go counter-clockwise. My painstakingly drilled "x = r cos theta, y = r sin theta" from tenth grade are also wrong.
  • Adding and subtracting angles. This is exacerbated by use of DMS (see above) but just on its own it is a Problem for me. Turns out I don't actually have an instinctive grasp of "left" and "right," I just have heuristics that have done well enough up til now. (Scott's "think about it like adding or subtracting time on a clock" was actually really helpful.)
The best things about mapping:
  • Getting to use trigonometry in real-world applications. Trig is beautiful (if messy) math and I have always admired how much information you can get out of one angle and one distance.
  • Universal Transverse Mercator, a coordinate system of map projections with minimal, calculable distortion and consistent, useful labeling.

(Icon is a 5000km circle centred in Paris. Stupid Mercator.)

Date: 2023-11-19 06:27 pm (UTC)
reedrover: (Default)
From: [personal profile] reedrover
Loving this post. Love the nerdy rants!

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Adventures in Mamboland

"Jazz Fish, a saxophone playing wanderer, finds himself in Mamboland at a critical phase in his life." --Howie Green, on his book Jazz Fish Zen

Yeah. That sounds about right.

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