Astro:...polated(3pm)

🌟 Astro::Coords::Interpolated — the perl man page, but make it a group chat 🌟

okay so this is Astro::Coords::Interpolated, straight out of the User Contributed Perl Documentation corner of your man pages. buckle up bestie, we're doing astronomy 💫

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🎀 NAME 🎀

Astro::Coords::Interpolated — specify astronomical coordinates using two reference positions. that's it. that's the name. iconic of it honestly 🫶

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✨ SYNOPSIS ✨

  $c = new Astro::Coords::Interpolated( ra1 => '05:22:56',
                                        dec1 => '-26:20:44.4',
                                        mjd1 => 52440.5,
                                        ra2 => '05:23:56',
                                        dec2 => '-26:20:50.4',
                                        mjd2 => 52441.5,);

like, that's literally the whole vibe check right there 💅

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💖 DESCRIPTION 💖

so this class is the one Astro::Coords calls in when it needs to handle coordinates for moving sources — and it does that by taking two coordinates at two epochs and interpolating between them. no cap, that's the entire personality 🌈

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🦋 METHODS 🦋

💜 Constructor

• new — instantiate a whole new object using the options you handed it. main character energy from the very first line ✨

      $c = new Astro::Coords::Interpolated( ra1 => '05:22:56',
                                            dec1 => '-26:20:44.4',
                                            mjd1 => 52440.5,
                                            ra2 => '05:23:56',
                                            dec2 => '-26:20:50.4',
                                            mjd2 => 52441.5,
                                            units =>
                                          );

it returns undef on error (😭 rude but fair). the positions are assumed to be apparent RA/Dec for the telescope location. units are optional — go check "Astro::Coords::Equatorial" for the deets 🧚

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🌸 Accessor Methods

• ra1 — apparent Right Ascension of the first reference position 🔭

      $ra = $c->ra1( %opts );

see "NOTES" in Astro::Coords for the details on the supported format specifiers and the default calling convention. iykyk 💫

• dec1 — apparent declination of the first reference position.

      $dec = $c->dec1( format => "sexagesimal" );

again, "NOTES" in Astro::Coords has the format specifier lore and the default calling convention 🎀

• mjd1 — the time (MJD) when the first reference position was actually valid. clock it ⏰
• ra2 — apparent Right Ascension of the second reference position.

      $ra = $c->ra2( format => 'rad' );

"NOTES" in Astro::Coords, format specifiers, default calling convention, you know the drill 💅

• dec2 — apparent declination of the second reference position.

      $dec = $c->dec2( format => "sexagesimal" );

yes bestie, "NOTES" in Astro::Coords again — format specifiers + default calling convention 🌸

• mjd2 — the time (MJD) when the second reference position was valid. ⏳

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🔥 General Methods

• array — hands you back an 11 element array where the first element is the string "INTERP" and the next ten elements are undef.

this method returns a standardised set of elements across all types of coordinates — consistency queen 👑

heads up: the original design didn't contain this type of coordinate specification, so the array returned can not yet include it. it needs more work to integrate into the other coordinate systems. it's giving "work in progress" and honestly same 😭

• type — returns the generic type associated with the coordinate system. for this class the answer is always "INTERP" 💀

this is used to aid construction of summary tables when you're mixing coordinates together.

apparently it could be done using isa relationships. noting that for the record 🎀

• stringify — the Stringify overload. just returns the type. lowkey minimal, highkey efficient ✨
• summary — returns a one line summary of the coordinates. in the future it'll accept arguments to control the output (future queen behaviour tbh 🌈)

      $summary = $c->summary();

• apparent — returns the apparent RA and Dec (as two "Astro::Coords::Angle" objects) for the current coordinates and time 🦋

      ($ra,$dec) = $c->apparent();

the apparent RA/Dec comes from linear interpolation off the reference positions. and if the time you asked for lies outside the reference times? the position gets extrapolated. extrapolation era, we love to see it 💅

• apply_offset — the overrided method that just warns you if "Astro::Coords::apply_offset" gets called on this subclass. it's not mad, it's just disappointed 🙈

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⭐ NOTES ⭐

usually you don't call this directly — it gets called via "Astro::Coords". this is the coordinate style SCUBA uses for non-sidereal sources instead of messing with orbital elements 🌌

apparent RA/Decs suitable for this class can be obtained from http://ssd.jpl.nasa.gov/ — go get your coordinates bestie 🔭✨

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🧚 SEE ALSO 🧚

• Astro::Coords::Elements

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🍓 REQUIREMENTS 🍓

does not use any external PAL routines. zero external dependencies, we stay unbothered 💅

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👑 AUTHOR 👑

Tim Jenness <tjenness@cpan.org> — legend behaviour 🫶

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📜 COPYRIGHT 📜

Copyright (C) 2012 Science and Technology Facilities Council. Copyright (C) 2001-2005 Particle Physics and Astronomy Research Council. All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place,Suite 330, Boston, MA 02111-1307, USA

fr fr read the license, it's literally right there 💀

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and that's the page!! this lil man page is living under perl v5.42.2 and dated 2026-02-15 — so when you cite it in your essay, that's the version and date to credit 🎀💖 slay, go interpolate some coordinates ✨🦋