Supported Subset of SymPy

This page lists the parts of SymPy’s symbolic algebra toolbox that pystencils is able to parse and translate into code. This includes a list of restrictions and caveats.

sympy.core

Symbols	sp.Symbol	Represent untyped variables
Integers	sp.Integer
Rational Numbers	sp.Rational	Non-integer rationals are interpreted using the division operation of their context’s data type.
Arbitrary-Precision Floating Point	sp.Float	Will initially be narrowed to double-precision (aka. the Python float type),
Transcendentals: \(\pi\) and \(e\)	sp.pi, sp.E	Only valid in floating-point contexts. Will be rounded to the nearest number representable in the respective data type (e.g. pi = 3.1415927 for float32).
Infinities (\(\pm \infty\))	sp.Infinity, sp.NegativeInfinity	Only valid in floating point contexts.
Arithmetic	sp.Add, sp.Mul, sp.Pow,	Integer powers up to \(8\) will be expanded by pairwise multiplication. Negative integer powers will be replaced by divisions. Square root powers with a numerator \(\le 8\) will be replaced by (products of) the sqrt function.
Relations (==, <=, >, …)	sp.Relational	Result has type boolean and can only be used in boolean contexts.
(Nested) Tuples	sp.Tuple	Tuples of expressions are interpreted as array literals. Tuples that contain further nested tuples must have a uniform, cuboid structure, i.e. represent a proper n-dimensional array, to be parsed as multidimensional array literals; otherwise an error is raised.

sympy.functions

Trigonometry	sp.sin, sp.asin, …	Only valid in floating-point contexts
Hyperbolic Functions	sp.sinh, sp.cosh,	Only valid in floating-point contexts
Exponentials	sp.exp, sp.log,	Only valid in floating-point contexts
Absolute	sp.Abs
Rounding	sp.floor, sp.ceiling	Result will have the same data type as the arguments, so in order to get an integer, a type cast is additionally required (see tcast)
Min/Max	sp.Min, sp.Max
Piecewise Functions	sp.Piecewise	Cases of the piecewise function must be exhaustive; i.e. end with a default case.

sympy.logic

Boolean atoms	sp.true, sp.false
Basic boolean connectives	sp.And, sp.Or, sp.Not

sympy.tensor

Indexed Objects

sp.Indexed

Base of the indexed object must have a PsArrayType of the correct dimensionality. Currently, only symbols (sp.Symbol or TypedSymbol) can be used as the base of an Indexed.