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Thermodynamical functions ​

ChemistryLab.ADIM_MATH_FUNCTIONS Constant
julia
ADIM_MATH_FUNCTIONS

The mathematical functions that take a dimensionless argument.

Used to extend SymbolicFunc and NumericFunc, which are this package's own types, so that a compiled or symbolic expression can be written with them. It is not used to extend them to DynamicQuantities.Quantity: that was type piracy, it applied to every package loaded beside this one, and it replaced a dimension error by an answer that depended on SI normalization. See _adim, which restores the check at the two places that needed one.

ChemistryLab.AbstractFunc Type
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AbstractFunc

Abstract type for objects that can be called like functions.

ChemistryLab.NumericFunc Type
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NumericFunc{N, F, R, Q} <: AbstractFunc

Closure-backed thermodynamic function for models that cannot be represented as symbolic expressions (e.g. HKF (Helgeson et al., 1981), or any other numeric model). Calling convention is identical to SymbolicFunc: f(; T=..., P=..., unit=false).

Variable values are resolved in order: kwarg > refs > _NF_DEFAULT_REFS. refs stores Quantity values so that unit information is preserved.

Fields

  • compiled: closure (vars...) → value in SI units.

  • vars: names of the positional arguments (e.g. (:T, :P)).

  • refs: NamedTuple of default variable values as Quantity (e.g. (T=298.15u"K", P=1e5u"Pa")).

  • unit: output unit (DynamicQuantities Quantity).

ChemistryLab.NumericFunc Method
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NumericFunc(f, unit)

Backward-compatible constructor: assumes vars = (:T, :P) and empty refs.

ChemistryLab.NumericFunc Method
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NumericFunc(f, vars, unit)

Construct a NumericFunc with no refs (fallback to _NF_DEFAULT_REFS).

ChemistryLab.SymbolicFunc Type
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SymbolicFunc(expr::Expr, vars=[:T, :P, :t, :x, :y, :z]; units, output_unit, kwargs...) -> SymbolicFunc

Create a SymbolicFunc from an expression. units and output_unit are those of ThermoFactory; the other keywords are the values of its parameters and the reference values of its variables.

ChemistryLab.SymbolicFunc Type
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SymbolicFunc

Thermodynamic function with symbolic expression and compiled evaluation.

ChemistryLab.SymbolicFunc Method
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SymbolicFunc(x::Number) -> SymbolicFunc

Create a constant SymbolicFunc from a number (unitless).

ChemistryLab.SymbolicFunc Method
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SymbolicFunc(x::Quantity) -> SymbolicFunc

Create a constant SymbolicFunc from a quantity.

ChemistryLab.SymbolicFunc Method
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SymbolicFunc(sym::Symbol; units, output_unit, kwargs...) -> SymbolicFunc

Create a SymbolicFunc from a single symbol. units and output_unit are those of ThermoFactory; the other keywords are the values of its parameters and the reference values of its variable.

ChemistryLab.ThermoFactory Type
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ThermoFactory(expr, vars=[:T, :P, :t, :x, :y, :z]; units=nothing, output_unit=nothing) -> ThermoFactory

Create a ThermoFactory from a symbolic expression.

Arguments

  • expr: symbolic expression (Expr or Symbol).

  • vars: list of variable symbols (default: T, P, t, x, y, z).

  • units: dictionary mapping symbols to their units; a symbol it does not list is dimensionless.

  • output_unit: the unit of the expression's value (dimensionless when nothing).

ChemistryLab.ThermoFactory Type
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ThermoFactory{Q}

Factory for creating SymbolicFunc instances from expressions. Units for each variable/parameter and the output unit are stored explicitly, so no symbolic unit propagation is needed.

ChemistryLab.ThermoFactory Method
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(factory::ThermoFactory)(; kwargs...)

Create a SymbolicFunc with caching for optimal performance. Safe to call from several threads at once.

Base.show Method
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Base.show(io::IO, ::MIME"text/plain", sf::SymbolicFunc)

Detailed string representation of a SymbolicFunc.

Base.show Method
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Base.show(io::IO, ::MIME"text/plain", factory::ThermoFactory)

Detailed string representation of a ThermoFactory.

Base.show Method
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Base.show(io::IO, sf::SymbolicFunc)

Compact string representation of a SymbolicFunc.

Base.show Method
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Base.show(io::IO, factory::ThermoFactory)

Compact string representation of a ThermoFactory.

ChemistryLab.apply_symbolic Method
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apply_symbolic(op, sf::SymbolicFunc)

Apply unary operation.

ChemistryLab.combine_symbolic Method
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combine_symbolic(op, x::Number, sf::SymbolicFunc)

Combine scalar with SymbolicFunc.

ChemistryLab.combine_symbolic Method
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combine_symbolic(op, sf::SymbolicFunc, x::Number)

Combine SymbolicFunc with scalar.

ChemistryLab.combine_symbolic Method
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combine_symbolic(op, sf1::SymbolicFunc, sf2::SymbolicFunc)

Combine two SymbolicFuncs.

ChemistryLab.compile_symbolic Method
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compile_symbolic(symbolic_expr, var_symbols)

Compile a symbolic expression to RuntimeGeneratedFunction.

ChemistryLab.derivative Method
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derivative(sf::SymbolicFunc, var::Symbol) -> SymbolicFunc

Compute the analytical derivative of sf with respect to variable var using Symbolics.jl and return a new SymbolicFunc for the result.

The output unit is inferred as sf.unit / unit_of_var, where unit_of_var is read from sf.refs (defaulting to dimensionless if var has no ref entry).

Examples

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Cp = SymbolicFunc(:(a + b*T + c/T^2); a=25.0, b=8e-3, c=-1.5e5)
dCp_dT = derivative(Cp, :T)   # ∂Cp/∂T
dCp_dT(T = 500.0)
ChemistryLab.extract_vars_params Method
julia
extract_vars_params(expr, vars) -> (Vector{Symbol}, Vector{Symbol})

Identify variables and parameters in an expression.

Arguments

  • expr: symbolic expression to analyze.

  • vars: list of symbols considered as variables (others are parameters).

Returns

  • Tuple of (variables, parameters) found in the expression.
ChemistryLab.get_unit Method
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get_unit(factory::ThermoFactory, sym::Symbol) -> Quantity

Get the unit of a specific variable or parameter in the factory.

ChemistryLab.get_unit Method
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get_unit(factory::ThermoFactory) -> Quantity

Get the output unit of the expression managed by the factory.