# Class OSNSMatrix¶

class OSNSMatrix

Interface to some specific storage types for matrices used in OneStepNSProblem.

This class is used to define an interface for various storage methods used for matrices in OneStepNSProblem. Its aim is to fill the Numerics structure NumericsMatrix, required in many XXX_problem structures of Numerics as input argument for drivers.

The idea is to remove all matrix storage management problems from OSNS classes (LCP …) and to leave it into this class.

Two main functions:

• fill(indexSet, interactionBlocks): fill the matrix using a list of “active” Interaction, in indexSet, and a MapOfMapOfInteractionMatrices, interactionBlocks, which determines which Interaction are connected or not (ie have common DynamicalSystem).
• convert(): fill the NumericsMatrix structure (indeed only pointers links to the components of the present class)

Note that OSNSMatrix are square.

For example, if in a LCP, constraints of interest are indexSet={inter2,inter3,inter8,inter12}, whith common DynamicalSystem between 2 and 3, 2 and 8 and 8 and 12.

interactionBlocks contains matrices for all (interi,interj) which have common DS, for (interi,interj) in I0, the set of all Interaction.

(for details on how interactionBlocks is computed see OneStepNSProblem.h).

We denote interactionBlocks[interi][interj] = mij

Then, a call to fill(indexSet, interactionBlock) results in a matrix which looks like:

M=\left\lbrace\begin{array}{cccc} m22 & m23 & m28 & 0 \\ m32 & m33 & 0 & 0 \\ 0 & 0 & m88 & m812 \\ 0 & 0 & m128& m1212 \end{array}\right.

Note: at the time the available storage types are:

• full matrix in a SiconosMatrix (_storageType = 0). In this case, for each call to fill(), the SiconosMatrix M is resized according to the sizes of the Interaction present in indexSet and then all the required interactionBlocks mij are COPIED into M.
• Sparse Block Storage (_storageType = 1): corresponds to SparseBlockStructuredMatrix structure of Numerics. Only non-null interactionBlocks are saved in the matrix M and there is no copy of sub-interactionBlocks, only links thanks to pointers.
• Sparse matrix (_storageType = 2): at the time of writting, only csc (compressed-sparse column). Could also be triplet (coo or coordinate) or csr (compressed-sparse row).

Subclassed by OSNSMatrixProjectOnConstraints

Public Functions

OSNSMatrix()

Default constructor -> empty matrix.

OSNSMatrix(unsigned int n, int stor)

Constructor with _dimRow.

of the matrix

Parameters
• n: size of the square matrix
• stor: storage type (0:dense, 1:sparse interactionBlock)

OSNSMatrix(unsigned int n, unsigned int m, int stor)

Constructor with _dimRow and DimColumn of the matrix.

Parameters
• n: row sizes of the rectangle matrix
• m: column size of the rectangle matrix
• stor: storage type (0:dense, 1:sparse interactionBlock)

OSNSMatrix(InteractionsGraph &indexSet, int stor)

Constructor from index set and map.

Parameters
• indexSet: InteractionsGraph* the index set of the active constraints
• stor: storage type

OSNSMatrix(const SiconosMatrix &MSource)

Constructor with copy of a SiconosMatrix => _storageType = 0.

Parameters
• MSource: matrix to be copied

virtual ~OSNSMatrix()

destructor

void convert()

fill the numerics structure _numericsMatSparse using MBlockCSR

SP::SiconosMatrix defaultMatrix()

get the matrix used for default storage

Return
SP::NumericsMatrix

void display() const

display the current matrix

virtual void fillH(DynamicalSystemsGraph &DSG, InteractionsGraph &indexSet, bool update = true)

fill the current class using an index set

Parameters
• DSG: the index set of the dynamicalSystems
• indexSet: the index set of the Interactions
• update: if true update the size of the Matrix (default true)

virtual void fillM(DynamicalSystemsGraph &DSG, bool update = true)

fill the current class using an index set

Parameters
• DSG: the index set of the dynamicalSystems
• update: if true update the size of the Matrix (default true)

virtual void fillW(InteractionsGraph &indexSet, bool update = true)

fill the current class using an index set

Parameters
• indexSet: the index set of the active constraints
• update: if true update the size of the Matrix (default true)

SP::NumericsMatrix numericsMatrix()

Return
SP::NumericsMatrix

void setStorageType(int i)

set which type of storage will be used for current matrix

Parameters
• i: the type of storage

unsigned int size() const

get dimension of the square matrix

Return
unsigned int

unsigned int sizeColumn() const

get dimension of the square matrix

Return
unsigned int

int storagetype() const

get the type of storage for current matrix

Return
unsigned int