Class BlockCSRMatrix¶
Defined in Program listing for file kernel/src/simulationTools/BlockCSRMatrix.hpp
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class BlockCSRMatrix¶
Definition of a compressed sparse row matrix of SiconosMatrix, used in OneStepNSProblem to store the M matrix.
This class defines a specific compressed row sparse storage for blocks matrices, each block being a SiconosMatrix*.
It handles:
a SparseMat (boost-ublas) of SiconosMatrix*
a vector<SiconosMatrix*> which handles the non-null blocks
three vector<int> (IndexInt) to save non-null blocks position in row, columns and the list of the sizes of diagonal blocks.
two int, the number of blocks in a row and the number of non null blocks.
Each block of the current object represents the connection between two coupled Interactions,
(for example for Lagrangian systems, a single \( H W^{-1} H^t \) block or for first order systems \( hCW^{-1}B \) …).
This objects is built using an index set of SP::Interaction, that represents the “active” constraints in the OSNS problem and a map<SP::Interaction u1, <SP::Interaction u2, SP::SiconosMatrix block> >, block being the link between u1 and u2. Only Interaction present in the index set are picked out in the map.
A convert method is also implemented to create a SparseBlockStructuredMatrix which is Numerics-readable.
As an example, consider the index set I={u1, u3, u5, u8} and the map where non null blocks are (ui,ui), (u1,u3), (u1,u8), (u3,u1), (u8,u1). Each block being a pointer to a 3x3 matrix. Then the resulting matrix has 4 X 4 blocks, with 8 non-null blocks and looks like:
\[\begin{split} M=\left\lbrace\begin{array}{cccc} b11 & b13 & 0 & b18 \\ b31 & b22 & 0 & 0 \\ 0 & 0 & b33&0 \\ b81 & 0 & 0 & b44 \end{array}\right. \end{split}\]with nc = 4, nbNonNullBlocks = 8, RowPos = [0 0 0 1 1 2 3 3], RowCol = [0 1 3 0 1 2 0 3] and _diagsize0 = [3 6 9 12].
We use std::vector (which may seems redundent with the double* of the numerics SparseBlockStructuredMatrix) because memory can be reserved during construction or initialized and then vectors are resized when the object is filled in. This avoid some call to malloc/free at each iteration.
Public Functions
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BlockCSRMatrix()¶
Default constructor -> empty matrix.
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BlockCSRMatrix(unsigned int n)¶
Constructor with dimension (number of blocks)
- Parameters
n – number of blocks in a row/column (only square matrices allowed)
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BlockCSRMatrix(InteractionsGraph &indexSet)¶
Constructor from index set.
- Parameters
indexSet – the index set of the active constraints
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~BlockCSRMatrix()¶
destructor
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inline unsigned int numberOfBlocksInARow() const¶
get size (in block-components)
- Returns
unsigned int NumberOfBlocksInARow
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unsigned int getNbNonNullBlocks() const¶
get total number of non-null blocks
- Returns
unsigned int
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inline SP::SparseBlockStructuredMatrix getNumericsMatSparse()¶
get the numerics-readable structure
- Returns
SP::SparseBlockStructuredMatrix
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inline IndexInt::value_type getSizeOfDiagonalBlock(int i) const¶
get the dimension of the square-diagonal block number num
- Parameters
i – block position
- Returns
unsigned int
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inline SP::IndexInt getPositionsIndex(bool i)¶
get the index of blocks position (i=0 -> rows, i=1 -> columns)
- Parameters
i – unsigned int, 0 for rows, 1 for columns
- Returns
SP::IndexInt
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void fill(InteractionsGraph &indexSet)¶
fill the current class using an index set
- Parameters
indexSet – set of the active constraints
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void fillW(InteractionsGraph &indexSet)¶
fill the matrix with the Mass matrix
Warning
only for NewtonEulerDS
- Parameters
indexSet – of the active constraints
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void fillH(InteractionsGraph &indexSet)¶
fill the matrix with the H matrix
Warning
only for NewtonEuler3DR
- Parameters
indexSet – of the active constraints
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void convert()¶
fill the numerics structure _sparseBlockStructuredMatrix using _blockCSR
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void display() const¶
display the current matrix