Data File Format


Since Regina version 3.0, data files are now saved in an optionally compressed XML format. If a data file is compressed, it can be piped through gunzip to recover the plain text XML.

This reference chapter documents the various XML elements that form a Regina data file and how they are used. The top-level element for a data file is reginadata.

Regarding international characters: As of Regina version 4.5 (May 2008), all XML data is encoded using UTF-8 (which includes plain ASCII as a subset). In versions 4.4 and earlier, data was encoded in LATIN1 without declaring this explicitly in the XML header; Regina is aware of this, and treats all older data files as LATIN1 when they are loaded.

Table of Contents

abeliangroup — An abelian group
allowstrict — Deprecated: see spanstrict
allowtaut — Deprecated: see spantaut
angleparams — Parameters for an angle structure enumeration
compact (filter) — A constraint on compactness
compact (surface) — Is a normal surface compact?
connected — Is a normal surface connected?
euler (filter) — A constraint on Euler characteristic
euler (surface) — The Euler characteristic of a normal surface
filter — A normal surface filter
filter (combination) — A logical combination surface filter
filter (properties) — A surface filter that uses basic properties
flags — An arbitrary set of flags
fundgroup — The fundamental group of a triangulation
group — A group presentation
H1 — The first homology group of a triangulation
H1Bdry — The first homology group of the boundary of a triangulation
H1Rel — The relative first homology group of a triangulation
H2 — The second homology group of a triangulation
line — A single line of text
op — A single logical operation
orbl (filter) — A constraint on orientability
orbl (surface) — Is a normal surface orientable?
packet — A single packet in a data file
packet (angle structure list) — An angle structure list packet
packet (container) — A container packet
packet (normal surface list) — A normal surface list packet
packet (PDF) — A PDF packet
packet (script) — A script packet
packet (surface filter) — A surface filter packet
packet (text) — A text packet
packet (triangulation) — A triangulation packet
params — Parameters for a normal surface enumeration
pdf — An encoded PDF document
realbdry (filter) — A constraint on real boundary
realbdry (surface) — Does a normal surface have real boundary?
reginadata — An entire Regina data file
reln — A relation in a group presentation
spanstrict — Does an angle structure list span a strict structure?
spantaut — Does an angle structure list span a taut structure?
splitsfce — Does a triangulation have a splitting surface?
struct — A single angle structure
surface — A single normal surface
tag — An individual packet tag
tet — A single tetrahedron in a triangulation
tetrahedra — The tetrahedra forming a triangulation
text — An arbitrary amount of text
threeball — Does a triangulation represent the 3-dimensional ball?
threesphere — Does a triangulation represent the 3-sphere?
turaevviro — A single Turaev-Viro invariant for a triangulation
twosided — Is a normal surface two-sided?
var — A single script variable
zeroeff — Is a triangulation 0-efficient?