Sage 9.5 Release Tour
current development cycle (2021)
Contents
Symbolics
Changes to symbolic expressions
symbolic_expression is now able to create vectors and matrices of symbolic expressions for more general inputs. #16761
- For example, if the input is a list or tuple of lists/tuples/vectors:
sage: M = symbolic_expression([[1, x, x^2], (x, x^2, x^3), vector([x^2, x^3, x^4])]); M [ 1 x x^2] [ x x^2 x^3] [x^2 x^3 x^4] sage: M.parent() Full MatrixSpace of 3 by 3 dense matrices over Symbolic Ring
- For example, if the input is a list or tuple of lists/tuples/vectors:
Symbolic expressions can no longer be called with positional arguments. #14270
This was deprecated since Sage 4.0, although a bug prevented the deprecation warning from being issued in Sage versions 8.4 to 9.3. #32319
Instead of (x+1)(2), write either (x+1)(x=2), or (x+1).subs(x=2), or ((x+1).function(x))(2).
Interface to Mathics, a free implementation of the Wolfram language
Sage now has an optional package providing Mathics, a free (open-source) general-purpose computer algebra system featuring Mathematica-compatible syntax and functions, and an interface to it.#31778
Linear Algebra
Manifolds
Algebra
Deprecated and removed functionality
The package sage.finance is now deprecated. (The module sage.finance.time_series is now available as sage.stats.time_series.) #32427
The module sage.interfaces.primecount is now deprecated. #32412
The package sage.media is now deprecated. #12673
The module sage.stats.basic_stats is now deprecated. #29662
In the deprecation messages, we point users to suitable numpy, and scipy.stats, and pandas functions. (Python 3 also comes with a basic ​built-in stats module, but much of its functionality is unfortunately incompatible with SageMath's number types, #28234.)
Package upgrades
Modularization and packaging changes
New distribution package: sage-setup
The build system of the Sage library, sage_setup, is now provided by a separate distribution package sage-setup. The source tree is the subdirectory pkgs/sage-setup/ of the Sage git repository. #29847
Pynac merged into the Sage library
The core of the symbolic expressions subsystem of Sage, an adaptation of the GiNaC library to Python known as Pynac, has been merged into the Sage library source code as src/sage/symbolic/ginac/; all future development of Pynac is intended to happen here. #32386, #32387
This removes an obstacle to Python packaging: Pynac was a shared library with a dependency on the Python C API but not an extension module, and it could not be installed using standard Python tools. Now the shared library is gone; all of Pynac (about 60kLOC of C++ code spread over 100 *.h and *.cpp files) is put in a single extension module sage.symbolic.expression. All other extension modules that used to link to libpynac (sage.libs.pynac.pynac, sage.symbolic.function, sage.symbolic.series etc.) have either been merged into sage.symbolic.expression, or the dependency has been resolved through refactoring. The integration of Pynac into the Sage source tree will also make it easier for Sage developers to make changes to symbolics.
Module-level "# optional - FEATURE" for doctests
In the Sage doctesting framework, a line of tests can be conditionalized on the presence of a feature, such as an installed optional package, using a comment of the form # optional - FEATURE.
Sage 9.5 extends this mechanism by allowing developers to mark all doctests in a Python file as conditional on a feature. #30778
These module-level directives go to the top of the source file and take the form
# sage.doctest: optional - FEATURE
Availability of Sage 9.5 and installation help
The first beta release in the 9.5 development series was tagged on 2021-08-31. The current development release is 9.5.beta2, tagged 2021-09-26.
See sage-devel for development discussions and sage-release for announcements of beta versions and release candidates.