SymbolicExpressions

The SymblicExpressions module provides a simple computer algebra system (CAS). The concrete subtypes of SymExpr provide a mathematical syntax to symbolically represent the relations that define the semantics of primitive and composite systems.

Const(value::Float64)

Wraps a Float64 literal as a SymExpr.

Eq(lhs::SymExpr, rhs::SymExpr)

Equation with a SymExpr on both sides of the equal sign.

Fields

• lhs: left hand side
• rhs: right hand side

Abstract supertype for symbolic expressions. Abstract subtypes are SymVal for all leaf nodes (values) that may appear in syntax trees and SymOp for all internal nodes (operations) of a SymExpr.

Abstract type for symbolic operations, i.e. internal nodes in a SymExpr syntax tree.

Abstract type for symbolic values, i.e. leaf nodes in a SymExpr syntax tree.

Abstract subtype of SymVal for symbolic variables, such as port variables, constraint variables, and parameters.

diff(expr::SymExpr, var::SymVar) -> SymExpr

Returns the derivative of the given SymExpr with respect to the given SymVar using symbolic differentiation.

foreach(f, expr::SymExpr, T::Type{<:SymExpr}) -> nothing

Goes from the root into the expression tree and whenever a node::T is encountered, calls f(node).

replace(f, expr::SymExpr, T::Type{<:SymExpr}) -> SymExpr

Transforms a SymExpr using a function f : T -> SymExpr, where T <: SymExpr. Goes from the root into the expression tree and whenever a node::T is encountered, it is replaced by the new node f(node).

ast(s::SymExpr) -> Expr

Transform a SymExpr into a Julia Expr. Together with the methods called in the returned Julia Expr, ast defines the semantics of the mathematical SymExpr syntax.