Astro:...s::Pert(3pm)

💫 NAME 💫

Astro::Montenbruck::Ephemeris::Pert — literally the module that does perturbation calculations. That's it, that's the vibe. ✨

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🎀 SYNOPSIS 🎀

Okay so here's how you actually use it, bestie:

use Astro::Montenbruck::Ephemeris::Pert qw /pert/;

($dl, $dr, $db) = (0, 0, 0); # Corrections in longitude ["],
$pert_cb = sub { $dl += $_[0]; $dr += $_[1]; $db += $_[2] };

$term
  = pert( T     => $t,
          M     => $m1,
          m     => $m3,
          I_min => 0,
          I_max => 2,
          i_min =>-4,
          i_max =>-1,
          callback => $pert_cb);
$term->(-1, -1,0, -0.2, 1.4, 2.0,  0.6,  0.1, -0.2);
$term->( 0, -1,0,  9.4, 8.9, 3.9, -8.3, -0.4, -1.4);
...

So pert hands you back a $term code ref, and then you call that thing with your index values and it goes brrr. 🌀

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🌸 DESCRIPTION 🌸

This module calculates perturbations for the Sun, the Moon, and all 8 planets. No cap — all of them. It's used internally by the Astro::Montenbruck::Ephemeris module, so like… it's the backbone. The main character behind the scenes. 👑

🦋 EXPORT 🦋

Here's what you get when you import, bestie:

• pert(%args)
• "addthe($a, $b, $c, $d)"

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✨ SUBROUTINES/METHODS ✨

🪐 pert(%args)

This one calculates the perturbations to the ecliptic heliocentric coordinates of the planet. Giving main-character energy to a planet near you. 💅

Named arguments

• T — time, measured in centuries since epoch 2000.0 ⏳
• M, m, I_min, I_max, i_min, i_max — internal indices (very mysterious, very demure 🔮)
• callback — a reference to a function that receives the corrections to the 3 coordinates and then typically goes ahead and applies them (peep the "SYNOPSIS" for the full picture 🫶)

🧚 addthe($a, $b, $c, $d)

This bad boy calculates c=cos(a1+a2) and s=sin(a1+a2) — and it does it via the addition theorems, using c1=cos(a1), s1=sin(a1), c2=cos(a2) and s2=sin(a2). Trigonometry ate and left no crumbs. 📐✨

Arguments

c1, s1, c2, s2

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🌈 AUTHOR 🌈

Sergey Krushinsky, "<krushi at cpan.org>" — an icon, fr fr. 🙌

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👑 COPYRIGHT AND LICENSE 👑

Copyright (C) 2009-2022 by Sergey Krushinsky

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. Slay, and also, like, legally slay. 💜

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okay that's the whole page bestie, go forth and perturb some planets 🌸🦋⭐

Sign-off time: this lil doc came from perl v5.42.2, dated 2026-02-15 — the same date as the Astro:...s::Pert(3pm) page itself. Periodt. 💅🎀