CSRMatrix

CSRMatrix is defined to handle Compressed Sparse Row matrix.

Currently following modules are defined.

CSRMatrix_ConstructorMethods
CSRMatrix_IOMethods
CSRMatrix_SparsityMethods
CSRMatrix_SetMethods
CSRMatrix_AddMethods
CSRMatrix_SetRowMethods
CSRMatrix_SetColMethods
CSRMatrix_SetBlockRowMethods
CSRMatrix_SetBlockColMethods
CSRMatrix_GetMethods
CSRMatrix_GetRowMethods
CSRMatrix_GetColMethods
CSRMatrix_GetSubMatrixMethods
CSRMatrix_GetBlockRowMethods
CSRMatrix_GetBlockColMethods
CSRMatrix_UnaryMethods
CSRMatrix_ILUMethods
CSRMatrix_LUSolveMethods
CSRMatrix_MatVecMethods
CSRMatrix_MatmulMethods
CSRMatrix_ReorderingMethods
CSRMatrix_DiagonalScalingMethods
CSRMatrix_MatrixMarketIO
CSRMatrix_Superlu
CSRMatrix_SpectralMethods
CSRMatrix_SchurMethods
CSRMatrix_DBCMethods
CSRMatrix_LinSolveMethods

Constructor methods

subroutine	description	status
Initiate	Initiate instance of CSRMatrix	done
Shape	Returns shape of the matrix	done
Size	Returns size of matrix	done
TotalDimension	Returns the total dimension	done
GetNNZ	Returns total number of non zeros	done
Allocate	Allocate memory for sparse matrix	done
Deallocate	Deallocate the data stored in CSRMatrix	done
CSRMatrixAPLSB	Add two csr matrix	done
CSRMatrixAPLSBSorted	Add two csr matrix	done

Unary Methods

Following subroutines are planned to include in this module

subroutine	description	status
`Scal`	Scale the sparse matrix	done
`Convert`	Convert CSR matrix to dense matrix and vice-versa	done
`ColumnSORT`	sorts the elements in increasing order of columns	done
`RemoveDuplicates`	clean up the CSR format matrix, remove duplicate entry, etc	done
`Clean`	This routine performs tasks related to the cleaning of sparse matrix.	done
`Copy`	copy of a matrix into another matrix (both stored csr)	done
`Get`	returns `a(i,j)` for any `(i,j)` from a CSR-stored matrix.	done
`DropEntry`	This routine removes any elements whose absolute value is small from an input matrix A and puts the resulting matrix in B.	done
`GetTranspose`	in-place transposition routine	done
`GetDiagonal`	extracts a specified diagonal from a matrix.	done
`GetLowerTriangle`	extracts lower triangular part	done
`GetUpperTriangle`	extracts upper triangular part	done
`GetSym`	Get the symmetric matrix from CSR matrix	done
`PermuteRow`	permutes the rows of a matrix (B = P A)	done
`PermuteColumn`	permutes the columns of a matrix (B = A Q)	done
`Permute`	permutes both the rows and columns of a matrix (B = P A Q )	done
`DVPERM`	permutes a real vector (in-place)	todo
`IVPERM`	permutes an integer vector (in-place)	todo
`FILTER`	filters elements from a matrix according to their magnitude	todo
`LEVELS`	gets the level scheduling structure for lower triangular matrices	todo
`AMASK`	extracts C = A mask M	todo
`RETMX`	returns the max absolute value in each row of the matrix	todo
`DIAPOS`	returns the positions of the diagonal elements in A.	todo
`EXTBDG`	extracts the main diagonal blocks of a matrix.	todo
`GETBWD`	returns the bandwidth information on a matrix.	todo
`BLKFND`	finds the block-size of a matrix.	todo
`BLKCHK`	checks whether a given integer is the block size of A.	todo
`INFDIA`	obtains information on the diagonals of A.	todo
`AMUBDG`	gets number of nonzeros in each row of A*B (as well as NNZ)	todo
`APLBDG`	gets number of nonzeros in each row of A+B (as well as NNZ)	todo
`RNRMS`	computes the norms of the rows of A	todo
`CNRMS`	computes the norms of the columns of A	todo
`ROSCAL`	scales the rows of a matrix by their norms.	todo
`COSCAL`	scales the columns of a matrix by their norms.	todo
`ADDBLK`	Adds a matrix B into a block of A.	todo
`GET1UP`	Collects the first elements of each row of the upper triangular portion of the matrix	todo
`XTROWS`	extracts given rows from a matrix in CSR format.	todo
`CSRKVSTR`	Finds block row partitioning of matrix in CSR format	todo
`CSRKVSTC`	Finds block column partitioning of matrix in CSR format	todo
`KVSTMERGE`	Merges block partitionings, for conformal row/col pattern	todo

All methods

📄️ Structure

CSRMatrix data type defines a sparse matrix in the CSR format. EASIFEM uses Sparsekit library for handling CSRMatrix.

📄️ AMatVec

This routine performs matrix vector multiplication for csrmatrix.

📄️ Allocate

This subroutine creates memory space for the sparse matrix.

📄️ AtMatVec

This routine performs transpose matrix vector multiplication for csrmatrix ($A^T\ cdot x$).

📄️ Clean

This routine performs tasks related to the cleaning of sparse matrix.

📄️ ColumnSort

This routine sorts the elements of a matrix (stored in Compressed Sparse Row Format) in increasing order of their column indices within each row. It uses insertion sort algorithm.

📄️ Convert

Convert() is a generic method, which can be used to change the format of matrix.

📄️ Deallocate

To Deallocate the data stored inside an instance of CSRMatrix_ use Deallocate() method.

📄️ DiagonalScaling

DiagonalScaling performs diagonal scaling on CSRMatrix.

📄️ Display

Display method displays the contents of CSRMatrix_ object.

📄️ DropEntry

This routine removes any element whose absolute value is small from an input matrix A and puts the resulting matrix in B.

📄️ Get

This function returns a single value from the sparse MATRIX.

📄️ GetBlockRow

This routine returns a row of a block csrmatrix.

📄️ GetColumn

This routine returns the column of a csrmatrix.

📄️ GetDiagonal

This routine returns the diagonal entries of sparse MATRIX.

📄️ GetILUD

This routine computes the ILU factorization with standard threshold dropping

📄️ GetILUDP

This routine computes ILUDP preconditioner: incomplete LU factorization with standard droppoing strategy.

📄️ GetILUK

This routine returns the ILU WITH LEVEL OF FILL-IN OF K (ILU(k))

📄️ GetILUT

This routine builds the ILUT precondition.

📄️ GetILUTP

Incomplete LU factorization with dual truncation mechanism

📄️ GetLowerTriangle

This subroutine returns the lower part of the sparse matrix.

📄️ GetNNZ

Returns the number of non-zero entries in csrmatrix.

📄️ GetRow

This routine returns a row of CSR matrix.

📄️ GetSym

Returns the symmetric form of a sparse matrix.

📄️ GetTranspose

In-place transposition routine. This subroutine transposes a matrix stored in compressed sparse row format.

📄️ GetUpperTriangle

This subroutine returns the Upper part of the sparse matrix.

📄️ Harwell-Boeing

The Harwell-Boeing format is the most popular mechanism for text-file exchange of sparse matrix data.

📄️ Import

Import() can be used for importing sparse matrix data from a file.

📄️ Initiate

Initiate() method constructs an instance of CSRMatrix_.

📄️ LUSolve

This routine solves the system LU x = y, given an LU decomposition of a matrix stored in (ALU, JLU, JU) modified sparse row format (MSR).

This routine solves the system (LU)^T x = y, given an LU decomposition of a matrix stored in (ALU, JLU, JU) modified sparse row format (MSR). This ALU, JLU, JU are created by calling ILUT methods described above