CENSUSLOOKUP(1)

💖 CENSUSLOOKUP 💖

okay bestie, welcome to censuslookup — it's a lil command-line baddie from The Regina Handbook that goes digging through Regina's census databases to find your triangulations. she's giving search-engine but for 3-manifolds. iconic behavior honestly 🦋

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✨ NAME ✨

censuslookup — search for triangulations in Regina's census databases 💅

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🎀 SYNOPSIS 🎀

censuslookup isosig ...

censuslookup { -v, --version | -?, --help }

no cap, that's the whole vibe.

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🌸 DESCRIPTION 🌸

so like, this utility searches for the given 3-manifold triangulations in the various census databases that are shipped with Regina. that's it, that's the job, and she does it flawlessly.

you should present the triangulations using their isomorphism signatures. these are short text strings that identify the triangulation uniquely up to combinatorial isomorphism — which is just fancy speak for "up to relabellings of the tetrahedra and/or their vertices". periodt. 💅

from the graphical user interface, you can view the isomorphism signature of a triangulation by switching to the Composition tab in the triangulation viewer. and from Python you can fetch the isomorphism signature of the triangulation x by calling x.isoSig(). for a full and precise specification of isomorphism signatures, see Simplification paths in the Pachner graphs of closed orientable 3-manifold triangulations, Burton, 2011, arXiv:1110.6080. 📚

all database matches (if any) will be written to standard output. and if there are none? she just says nothing about it. we love a low-drama queen 🫶

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💅 OPTIONS 💅

• -v, --version — show which version of Regina is being used, and exit immediately. boom, done, bye ✨
• -?, --help — display brief usage information, and exit immediately. the "bestie explain" button 🎀

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🦋 ENVIRONMENT VARIABLES 🦋

the following environment variables influence the behaviour of this program. yes she reads the room. yes she reads your env. 🌈

REGINA_HOME

the directory beneath which Regina's data files are installed. this utility will look for the census databases in the subdirectory $REGINA_HOME/data/census/.

normally you should not need to set this option yourself. this utility should know how to find its census databases in standard situations, which include fixed filesystem installations (e.g., GNU/Linux and Windows), relocatable app bundles (e.g., macOS), and running directly from the source tree. she's self-sufficient, she's independent, she has main character energy 👑

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🌈 EXAMPLE 🌈

example$ censuslookup fvPQcdecedekrsnrs dLQbcccajqs cPcbbbiht
fvPQcdecedekrsnrs: 1 hit
    SFS [S2: (2,1) (3,1) (5,-4)] : #1 -- Closed census (orientable)

dLQbcccajqs: 0 hits

cPcbbbiht: 2 hits
    m004 : #1 -- Cusped hyperbolic census (orientable)
    L104001 -- Hyperbolic knot and link complements

example$

look at her go!! one hit, zero hits, two hits — the range, the versatility 😭💖

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🍓 MACOS USERS 🍓

if you downloaded a drag-and-drop app bundle, this utility is shipped inside it. if you dragged Regina to the main Applications folder, you can run it as /Applications/Regina.app/Contents/MacOS/censuslookup. she's in there. she's been in there the whole time. 🙈

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💀 WINDOWS USERS 💀

the command-line utilities are installed beneath the Program Files directory; on some machines this directory is called Program Files (x86). you can start this utility by running:

c:\Program Files\Regina\Regina 7.4.1\bin\censuslookup.exe

yes the path is long. yes it's giving "deeply nested". we still stan. 🌸

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👑 SEE ALSO 👑

regina-gui. trisetcmp,

(yes the comma is there. we keep the comma. the comma stays. 💅)

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💜 AUTHOR 💜

this utility was written by Benjamin Burton <bab@maths.uq.edu.au>. many people have been involved in the development of Regina; see the users' handbook for a full list of credits. we love a collaborative queen ✨

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and that's the whole page bestie!! 🌟 this edition dropped on 25 August 2025, and the manual is literally just called CENSUSLOOKUP(1) — so if you see that name floating around, that's her, that's the girl. go forth and look up some censuses. iykyk 💖🎀🦋