# Class Equality¶

class Equality : public LinearOSNS

Formalization and Resolution of a Linear Complementarity Problem (Equality)

## Aim of the Equality class¶

This class is devoted to the formalization and the resolution of the Linear system (Equality) defined by : $$0 = w = q + M z$$ where

• $$w \in R^{n}$$ and $$z \in R^{n}$$ are the unknowns,

• $$M \in R^{n \times n }$$ and $$q \in R^{n}$$

The Equality main components are:

• a problem (variables M,q and size of the problem), which directly corresponds to the LinearComplementarityProblem structure of Numerics

• the unknowns z and w

Public Functions

Equality(int numericsSolverId = 0)

constructor from data

Parameters

numericsSolverId – id of numerics solver, default = 0

Equality(SP::SolverOptions options)

constructor from a pre-defined solver options set.

Parameters

options, the – options set,

see Nonsmooth problems formulations and available solvers for details.

inline ~Equality()

destructor

virtual void initialize(SP::Simulation sim)

initialize

Parameters

sim – the simulation

virtual int compute(double time)

Compute the unknown z and w and update the Interaction (y and lambda )

Parameters

time – double : current time

Returns

int information about the solver convergence.

virtual void updateM()

Build or reinit M and the NumericsProblem.

virtual void display() const

print the data to the screen