13 Jul 2013
This release includes Risch integration algorithm from Aaron Meurer’s 2010 Google Summer of Code project. This makes
integratemuch more powerful and much faster for the supported functions. The algorithm is called automatically from
integrate(). For now, only transcendental elementary functions containing
logare supported. To access the algorithm directly, use
integrate(expr, x, risch=True). The algorithm has the ability to prove that integrals are nonelementary. To determine if a function is nonelementary, integrate using
risch=True. If the resulting
Integralclass is an instance of
NonElementaryIntegral, then it is not elementary (otherwise, that part of the algorithm has just not been implemented yet).
Built basic infrastructure of the PDE module (sympy/sympy#1970)
SymPy expressions can now be translated into Theano expressions for numeric evaluation. This includes most standard scalar operations (e.g.
gamma, but not
MeijerG) and matrices. This system generally outperforms
autowrapbut does require Theano to be installed.
Matrix expressions now support inference using the new assumptions system. New predicates include
New operators include
DFT. Also, preliminary support exists for factorizations like
Context manager for New Assumptions
with assuming(*facts)context manager for new assumptions. See blogpost.
This is the last version of SymPy to support Python 2.5.
The IPython extension, i.e.,
%load_ext sympy.interactive.ipythonprintingis deprecated. Use
from sympy import init_printing; init_printing()instead. See sympy/sympy#7013.
previewwithout a file name is deprecated. Use
filename='name'in addition to
viewer='file'. See sympy/sympy#7018.
The deprecated syntax
Symbol('x', dummy=True), which had been deprecated since 0.7.0, has been removed. Use
symbols('x', cls=Dummy)instead. See sympy/sympy#6477.
as_coeff_factors, which have been deprecated in favor of
as_coeff_add, respectively (see also
as_coeff_Add), were removed. The methods had been deprecated since SymPy 0.7.0. See sympy/sympy#6476.
The spherical harmonics have been completely rewritten. See sympy/sympy#1510.
Support for first order linear general PDE’s with constant coefficients (sympy/sympy#2109).
Return all found independent solutions for underdetermined systems.
Handle recursive problems for which
y(0) = 0.
Handle matrix equations.
integratewill split out integrals into Piecewise expressions when conditions must hold for the answer to be true. For example,
integrate(x**n, x)now gives
Piecewise((log(x), Eq(n, -1), (x**(n + 1)/(n + 1), True))(previously it just gave
x**(n + 1)/(n + 1)).
Calculate Gauss-Legendre and Gauss-Laguerre points and weights (sympy/sympy#1497).
Various new error and inverse error functions (sympy/sympy#1703).
Use in heurisch for more symmetric and nicer results.
Gruntz for expintegrals and all new erf*.
Li, li logarithmic integrals (sympy/sympy#1708).
Integration of li/Li by heurisch (sympy/sympy#1712).
elliptic integrals, complete and incomplete.
Integration of complete elliptic integrals by meijerg.
Integration of Piecewise with symbolic conditions.
Fixed many wrong results of DiracDelta integrals.
Addition of SOPform and POSform functions to sympy.logic to generate boolean expressions from truth tables.
Addition of simplify_logic function and enabling
simplify()to reduce logic expressions to their simplest forms.
Addition of bool_equals function to check equality of boolean expressions and return a mapping of variables from one expr to other that leads to the equality.
Addition of disjunctive normal form methods - to_dnf, is_dnf
gmpy version 2 is now supported
Many improvements to the handling of noncommutative symbols:
Better support in simplification functions, e.g.
Better integration with
Better pattern matching
Improved pattern matching including matching the identity.
normalizes Jacobi polynomials
Quadrature rules for orthogonal polynomials in arbitrary precision (hermite, laguerre, legendre, gen_legendre, jacobi)
summation of harmonic numbers
Many improvements of the polygamma functions
evaluation at special arguments
Connections to harmonic numbers
structured full partial fraction decomposition (mainly interesting for developers)
Karr summation convention
New spherical harmonics
improved minimal_polynomial using composition of algebraic numbers (sympy/sympy#2038).
faster integer polynomial factorization (sympy/sympy#2148).
Euler-Descartes method for quartic equations (sympy/sympy#1947)
algebraic operations on tensors (sympy/sympy#1700).
tensor canonicalization (sympy/sympy#1644).
Handle the simplification of summations and products over a KroneckerDelta.
Implemented LaTeX printing of DiracDelta, Heaviside, KroneckerDelta and LeviCivita, also many Matrix expressions.
Improved LaTeX printing of fractions, Mul in general.
IPython integration and printing issues have been ironed out.
Stats now supports discrete distributions (e.g.
Poisson) by relying on
Added DOT printing for visualization of expression trees
Added information about solvability and nilpotency of named groups.