3.2.11.5. causality/Stochsim.hpp

3.2.11.5.1. Class causality::MassActionKinetics

class causality::MassActionKinetics

A helper class for performing stochastic simulations where events are drawn according to the law of mass action. Importantly, if the underlying derivation graph is enlarged then syncSize() must be called before calling draw().

3.2.11.5.1.1. Synopsis

MassActionKinetics(std::shared_ptr<dg::DG> dg_, std::function<double(dg::DG::Vertex)> inputRate, std::function<double(dg::DG::HyperEdge)> reactionRate, std::function<double(dg::DG::Vertex)> outputRate)
void syncSize()
std::pair<std::optional<Action>, double> draw(const DGPetriNetMarking &m)

3.2.11.5.1.2. Details

MassActionKinetics(std::shared_ptr<dg::DG> dg_, std::function<double(dg::DG::Vertex)> inputRate, std::function<double(dg::DG::HyperEdge)> reactionRate, std::function<double(dg::DG::Vertex)> outputRate)

Construct a new instance, based on the given derivation graph. The rates returned by the input, reaction, and output rate callbacks may be cached.

Throws

LogicError if !dg_.

Throws

LogicError if neither dg_->hasActiveBuilder() nor dg_->isLocked().

Throws

LogicError if !inputRate.

Throws

LogicError if !reactionRate.

Throws

LogicError if !outputRate.

void syncSize()

Enlarges the internal data structures to the current size of the underlying derivation graph.

std::pair<std::optional<Action>, double> draw(const DGPetriNetMarking &m)
Returns

an action, randomly selected according to the low of mass action based on the given population/marking and the rates. The second returned component is the sum of reactivity for the given reactions/hyperedges.

If no events are possible, then the second component is 0.0 and the first component has no vallue.

Use rngReseed() to seed the pseudo-random bit generator used for the selection.

Throws

LogicError if m is not a marking on the underlying derivation graph.

Requires syncSize() to have been called since the last time the underlying derivation graph has changed size.