GIS::D...:Cosine(3pm)

💖 NAME 💖

okay so bestie, meet GIS::Distance::Cosine ✨ — it lives in the User Contributed Perl Documentation corner of the perl-verse (you'll see it hanging out as GIS::D...:Cosine(3pm) when the terminal truncates it, rip to long names 😭). Its whole job? Spherical law of cosines distance calculations. That's it, that's the gig 💅

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🌸 DESCRIPTION 🌸

so here's the tea, and it's a little bittersweet 🍓:

Although this formula is mathematically exact, it is unreliable for small distances.

like… she's correct on paper, she's giving mathematically exact, but for tiny distances? nope, she's not it. 💀 See GIS::Distance::MathTrig for related details if you want the full lore.

now, if you want the fast version of this exact same formula, there's a faster (XS) one available as GIS::Distance::Fast::Cosine 🔥 XS = compiled C energy, no cap.

and the biggest vibe check of all: normally this module is not used directly. 🙈 Instead, GIS::Distance is used, which in turn interfaces with the various formula classes. So like, this module is the main character's best friend, not the main character — it does its thing behind the scenes 👑

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🎀 FORMULA 🎀

here's the math, and yes she's pretty 🦋:

a = sin(lat1) * sin(lat2)
b = cos(lat1) * cos(lat2) * cos(lon2 - lon1)
c = arccos(a + b)
d = R * c

that's the whole recipe, periodt. 💜

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⭐ SEE ALSO ⭐

• <https://en.wikipedia.org/wiki/Spherical_law_of_cosines> — go read up bestie, iykyk 📚

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🫶 SUPPORT 🫶

See "SUPPORT" in GIS::Distance.

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👑 AUTHORS 👑

See "AUTHORS" in GIS::Distance.

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🌈 LICENSE 🌈

See "LICENSE" in GIS::Distance.

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perl v5.36.0 🌸 2023-10-21 🌸 GIS::D...:Cosine(3pm) — mwah, that's the page, thanks for coming to my ted talk, love u, bye bestie 💖✨🎀