Sage 3.3 Release Tour

Sage 3.3 was released on FIXME. For the official, comprehensive release notes, see sage-3.3.txt. In general terms, the following points are some of the foci of this release:

• Clean up various doctest failures from 3.2.3
• Fix some build issues from 3.2.3 on the new set of supported images
• Merge small to medium sized patches ready to go in

• Switch to eMPIRe for multi-precision integers and rationals

• Switch to ecl for a Common Lisp implementation

• Update Python to 2.5.4

• Update Pari to 2.3.4svn

• Switch to FLINT for univariate polynomial arithmetic over Z/nZ

Here's a summary of features in this release, categorized under various headings.

Algebra

• Transitivity for permutation groups (William Stein) -- In the permutation group module permgroup.py, the query function is_transitive() returns whether or not the group is transitive on [1..G.degree()]. A few surrounding docstrings are fixed and doctest coverage for the file sage/groups/perm_gps/permgroup.py is now 100%.

Algebraic Geometry

• Improved precision and performance when calculating analytic rank (William Stein) -- When calculating the analytic rank of an elliptic curve, the default is to use Cremona's gp script, where the precision is automatically doubled until it doesn't fail. The precision is started at 16 rather than the previous default precision. The computation is now about 3 times faster usually by starting off using this smaller precision.

Basic Arithmetic

• ivalue field in integer_mod.pyx is no longer public (Craig Citro) -- The ivalue field for IntegerMod_int is no longer public. This gives about a 1.5 to 2X speedup when multiplying IntegerMod_ints.

• Some fixes for is_perfect_power and bessel_J(0,0) (Craig Citro, Robert Bradshaw, Robert Miller) -- A temporary work around for an upstream bug in GMP when using is_perfect_power(). Resolved a Pari interface bug when using bessel_J(0,0).

• Improved performance for generic polynomial rings, and for univariate polynomial arithmetic over Z/nZ[x] (Yann Laigle-Chapuy, Martin Albrecht) -- Improved performance when performing modulo arithmetic between elements of a generic polynomial ring. Univariate polynomial arithmetic over Z/nZ[x] now has considerable speed-up at approximately 20x.

Build

• 64-bit OSX (Michael Abshoff) -- Fixed 64-bit OSX build support for f2c, added 64-bit OSX build support for tachyon, added 64-bit OSX build support for flintqs, and added persistent Sage 64-bit building switch on OSX and Solaris.

Calculus

• LaTeX output (Mike Hansen) -- Added LaTeX output for ceiling, floor, and derivative functions, and LaTaX'ing of powers of negative numbers.

• Make bernoulli_polynomial independent of Maxima (Craig Citro) -- A rewrite of bernoulli_polynomial to avoid using Maxima completely in computing Bernoulli polynomials. This gives roughly a factor of 10 speedup.

Coding Theory

• Weight distribution for binary codes (Robert Miller) -- A weight distribution algorithm for binary codes using Robert Bradshaw's bitsets. This implementation in Cython gives a 19 to 20 times performance speed-up over the previous GAP/Guava implementation.

Coercion

• Ring coercion for polynomials over finite fields (William Stein).
• Move univariate polynomial rings to new coercion model (Robert Bradshaw).

Combinatorics

Commutative Algebra

• Multivariate polynomials over residue fields of number fields (Nick Alexander) -- Fixed an infinite loop bug when working with multivariate polynomials over residue fields of number fields. Previously in hashing "large" characteristic residue fields, the hash method would try to hash an ideal of the residue field itself, which in turn would try to hash its parent, and so on ad infinitum. At no point has a residue field with cardinality a very large prime been created in Sage.
• GCD of polynomials over finite fields (Martin Albrecht) -- Previously when using ibsingular to compute the GCD of two (multivariate) polynomials over finite fields, Sage would segfault whenever the base rings are not identical.

• Deprecate Ideal.reduced_basis (John Perry) -- The previous name Ideal.reduced_basis is misleading as it suggests that it can be used for computing the reduced Gröbner basis, when in fact it returns the interreduced basis. Thus Ideal.reduced_basis() is now deprecated and users are encouraged to use Ideal.interreduced_basis() instead.

Distribution

• GAP configuration file (Matthias Meulien) -- A user's local GAP configuration file is usually named $HOME/.gaprc. When such a file already exists and Sage is compiled from source, using the Sage interface to GAP, e.g. gap._eval_line('1+3;'), can result in gibberish. This is now fixed so that the GAP interface would output a comprehensible message/answer as a result of some GAP calculation.

Documentation

Geometry

• Polyhedral improvements (Marshall Hampton) -- Added more built-in Archimedean solids and some new methods such as the Gale transform, bipyramid construction, edge truncation, and perspective projection with (optionally) hidden faces invisible. The Schlegel projection code has also been somewhat refactored to make it more general in the future.

Graph Theory

• Equality testing in graphs (Robert Miller) -- The "weighted" property or edge label is taken into account when testing for equality in graphs.

Graphics

• Plotting a region (Arnaud Bergeron) -- Plot a region where a system of equations/inequalities were true.

• Consistency in variable range (Mike Hansen, Jason Grout) -- The variable range of parametric_plot is now consistent with that of plot, namely (var, min, max).

• Polar plot syntax (Jason Grout) -- Polar plot now accepts the syntax (t, 0, 2*pi) for the interval.

• Added a density_plot() function and improve colour map handling (Arnaud Bergeron) -- The density_plot takes a function of two variables and plots contour lines of the function over two specified ranges. Some improve on how colour map is handled.

Group Theory

• Added an is_cyclic method (David Joyner) -- The is_cyclic method for (finite) groups is currently not as optimized as it should be. Given a finite abelian group, one can test to see whether or not it is cyclic, a test that depends on calculating the elementary divisors of the group. As correctness is the main concern in the current implementation of elementary_divisors(), performance is not taken into account. However, the docstring for elementary_divisors() describes an algorithm communicated by Robert Miller for speeding up this method.

Interfaces

• Magma interface (William Stein) -- Fixed a problem in Sage's interface to Magma so that now the Magma .sig files in extcode are no longer written there by Magma itself. The current behaviour is that the first (and only first) time a Magma interface is started in a given session, files in data/extcode/magma are copied to a temporary directory.

• GAP interface (Mike Hansen) -- Ensured that the GAP interface handles keyboard interrupt gracefully, that GAP output would be printed, and that multi-line input and comments are handled as expected.
• Sage preparser (Robert Bradshaw) -- Some simplification of the Sage preparser, together with improved handling of literal numbers.

Linear Algebra

Memory Leak

Miscellaneous

Modular Forms

Notebook

Number Theory

Numerical

Optional Packages

Packages

Porting

Solaris

User Interface

Website/Wiki