News

• Version 3.1 (May 2023):

  • A method exterior_to_link for going from a link exterior to a link diagram taken from Dunfield-Obeidin-Rudd.

  • Covers now computed by the stand-alone low_index module, which uses multiple processor cores and is typically much faster than the old code. In some cases, it is dramatically faster than even GAP or Magma.

  • Added geodesics to the inside_view.

  • Added drilling any simple geodesic with drill_word and drill_words, not just those that are combinatorially simple.

  • Added ignore_orientation flag to triangulation_isosig.

  • Added include_words flag to length_spectrum for getting the word corresponding to a geodesic which can be given to drill_word.

  • Support for Python 3.11 and SageMath 10.0.

  • Modernized styling of the documentation.

• Version 3.0.3 (December 2021):

  • Runs natively on Macs with Apple Silicon processors (M1, M2, and variants).

• Version 3.0.2 (November 2021):

  • Support for SageMath 9.4 and 9.5, Python 3.10, and macOS Monterey.

• Version 3.0 (April 2021): New features include:

  • Incorporates Zoltán Szabó’s program for computing Knot Floer homology, see knot_floer_homology. This can compute the Seifert genus of a 25 crossing knot in mere seconds!

  • Topological slice obstructions of Herald-Kirk-Livingston, see slice_obstruction_HKL.

  • Faster “local” algorithm for jones_polynomial.

  • Cohomology fractals added to inside_view.

  • Convention changes: Sign of knot signature (now positive knots have negative signatures), choice of braid generators (now positive generators give positive crossings).

  • Updates to methods cusp_translations, cusp_areas, short_slopes. Also Link now accepts DT codes.

  • Support for SageMath 9.3, Python 3.9, and macOS Big Sur.

  • macOS app now code-signed and notarized.

  • SnapPy now requires Python 3.6 or newer.

• Version 2.8 (June 2020): New features include:

  • Raytraced interior views of a hyperbolic 3-manifold via the inside_view method, see also images and demo video.

  • Verified computations: Several new features:

    • Complex volume (and thus the Chern-Simons invariant) for both cusped and closed manifolds, see complex_volume.

    • Disjoint cusp neighborhoods by the method cusp_areas which uses cusp_area_matrix.

    • Cusp shapes (see cusp_info).

    • Finding all short_slopes in disjoint embedded cusp neighborhoods.

  • The census HTLinkExteriors has been extended to 15 crossing knots (contributed by Malik Obeidin).

  • The census CensusKnots has been extended to triangulations with 9 ideal tetrahedra.

  • Support for SageMath 9.0 and macOS Catalina.

  • Development moved to GitHub.

• Version 2.7 (July 2019): New features include:

  • Python 3 is now recommended over Python 2 on all platforms; the default Mac and Windows apps use Python 3 rather than Python 2. The only difference most users will notice is that one must type print(blah) instead of print blah.

  • Verified computations: performance improvements by switching to the Krawczyk test.

  • Support for SageMath 8.8.

  • Installation instructions extensively updated.

  • GUI improvements, especially on macOS. These include improved support for dark mode and tabs on macOS Mojave and preliminary support for macOS Catalina.

• Version 2.6.1 (August 2018): New features include:

  • Support for SageMath 8.3, Python 3.7, and macOS Mojave.

  • Computing ideals defining SL(2, C) character varieties. Contributed by Jean-Philippe Burelle, based on this paper.

  • Many bug fixes.

• Version 2.6 (Nov 2017): New features include:

  • Support for macOS High Sierra, SageMath 8.1, and Windows systems using non-Latin alphabets.

  • Many bug fixes, including improved Python 3 support.

• Version 2.5 (Feb 2017): New features include:

  • Rigorous computation of hyperbolic volume.

  • STL export of Dirichlet domains for 3D printing, contributed by Jose Sanchez.

  • Support for Python 3, SageMath 7.5, 7.6, and 8.0, and many more versions of Python on Windows.

  • Much improved infrastructure for testing and distributing SnapPy.

• Version 2.4 (May 2016): New features include:

  • Added census of Platonic manifolds.

  • Rigorous computation of cusp translations.

  • Added decorations to triangulation isomorphism signatures for encoding peripheral curves.

  • Faster verification of non-tetrahedral canonical cell decompositions.

  • Improvements to the link and planar diagram component, mostly contributed by Malik Obeidin, include:

    • Bar-Natan’s super-fast tangle-based algorithm for computing the Alexander polynomial.

    • Can now compute the Seifert matrix and express a link as a braid closure.

    • Conversion to/from SageMath links and braids.

    • Many under-the-hood improvements.

  • New Windows installer.

• Version 2.3 (March 2015): New features include:

  • Major improvements to the link and planar diagram component, including link simplification, random links, and better documentation.

  • Basic support for spun normal surfaces.

  • New extra features when used inside of Sage:

    • HIKMOT-style rigorous verification of hyperbolic structures, contributed by Matthias Goerner.

    • Many basic knot/link invariants, contributed by Robert Lipschitz and Jennet Dickinson.

    • Sage-specific functions are now more easily accessible as methods of Manifold and better documented.

    • Improved number field recognition, thanks to Matthias.

  • Better compatibility with OS X Yosemite and Windows 8.1.

  • Development changes:

    • Major source code reorganization/cleanup.

    • Source code repository moved to Bitbucket.

    • Python modules now hosted on PyPI, simplifying installation.

• Version 2.2 (June 2014): Includes Ben Burton’s census of orientable cusped manifolds with 9 tetrahedra.

• Version 2.1 (February 2014): New high-precision manifolds (ManifoldHP) which compute hyperbolic structures (and everything related) in quad-double (212 bit) precision.

• Version 2.0 (September 2013): Many new features, including:

  • A manifold browser window for easily examining a particular manifold.

  • Many improvements to the link editor, including

    • A smoothed view mode with image export to EPS/PDF/SVG/TikZ.

    • Producing a fully editable link from combinatorial data like a DT code.

  • Splitting manifolds along surfaces of non-negative euler characteristic.

  • Generalizing the ptolemy obstruction class to allow computation of PGL(3,C)-representations and improving usability of the ptolemy module.

  • CensusKnots now includes knot exteriors with 8 tetrahedra.

• Version 1.8 (May 2013) improves handling of DT codes and adds the HTLinkExteriors census, which provides identification for knots and links up to 14 crossings.

• Version 1.7 (November 2012) incorporates the ptolemy module for studying representations of 3-manifold groups into pSL(N, C).

• Version 1.6 (August 2012) includes a new way to make links and some support for arbitrary precision calculation.

• Version 1.5 (February 2012) includes much improved manifold censuses.

• Version 1.4 (December 2011) uses the current release of IPython, which has been completely rewritten.

• Version 1.3.10 (July 2011) incorporates Twister.

• Version 1.3 (February 2011) has a completely redesigned cusp horoball viewer and many bug fixes!

• Version 1.2 (December 2010).

• Version 1.1 (February 2010).

• Version 1.0 (August 2009) Initial version.