Initiate

Initiate() method constructs an instance of CSRMatrix_.

At present, there are 6 interfaces to initiate method. You can see their interface and examples below.

Calling example:

CALL Initiate(CSRMatrix_::obj, Integer::ncol, Integer::nrow &
  & [, DOF_::idof, DOF_::jdof, CHAR::MatrixProp] )
!!
CALL Initiate(CSRMatrix_::obj, CSRSparsity_::csr [, CHAR::matrixProp])
!!
CALL Initiate(CSRMatrix_:: obj, Real::A(:), Integer::IA(:), Integer::JA(:) &
  & [, CHAR::MatrixProp])
!!
CALL Initiate(CSRMatrix_::obj, CSRMatrix_::obj2)
!!
CALL Initiate(CSRMatrix_::obj, CSRMatrix_::obj2, &
  & Integer::i1, Integer::i2, Integer::j1, Integer::j2)

Interface

܀ Initiate(obj, ncol, nrow, idof, jdof, matrixProp)
️܀ Example 1
️܀ Example 2
↢

INTERFACE
  MODULE SUBROUTINE Initiate(obj, ncol, nrow, idof, jdof, matrixProp)
    TYPE(CSRMatrix_), INTENT(INOUT) :: obj
    INTEGER(I4B), INTENT(IN) :: ncol
    !! number of columns in sparse matrix
    INTEGER(I4B), INTENT(IN) :: nrow
    !! number of rows in sparse matrix
    TYPE(DOF_), OPTIONAL, INTENT(IN) :: idof, jdof
    !! degree of freedom object; It contains information like
    !! storage format (NODES_FMT, DOF_FMT), and names of physical variable
    !! space-time component in each physical variables
    !! Total number of nodes used for these physical variables
    CHARACTER(LEN=*), OPTIONAL, INTENT(IN) :: MatrixProp
    !! Matrix is `SYM`, `UNSYM`
  END SUBROUTINE Initiate
END INTERFACE

If user has information about the number of rows nrow, number of columns ncol of sparse matrix, then the above interface can be used to initiate an instance of CSRMatrix_.

dof and matrixProp are optional.
dof is DOF object, and it is used to initiate obj%csr, CSRSparsity field.

PROGRAM main
  USE easifemBase
  IMPLICIT NONE
  TYPE( CSRMatrix_ ) :: obj
  TYPE( DOF_ ) :: dofobj

First, we initiate DOF, which contains the structure of Degrees of freedom
The degrees of freedom has:
- 1 physical variable
- 1 space component
- 1 time component
- 12 number of spatial nodes are stored in NODES_FMT.

  CALL Initiate( obj=dofobj, tNodes=[12], names=['K'], &
    & spaceCompo=[1], timeCompo=[1], storageFMT=NODES_FMT )

Below we create a sparse matrix with 12 number of rows and 12 number of cols.

  CALL Initiate( obj, ncol=12, nrow=12, idof=dofobj, jdof=dofobj )

  CALL Deallocate( obj )
END PROGRAM main

PROGRAM main
    USE easifemBase
    IMPLICIT NONE
    TYPE( CSRMatrix_ ) :: obj
    TYPE( DOF_ ) :: dofobj
    REAL( DFP ), ALLOCATABLE :: m2(:,:)

Initiate degrees of freedom object DOF

    CALL Initiate( obj=dofobj, tNodes=[4, 2], names=['V', 'P'], &
      & spaceCompo=[2, 1], timeCompo=[1,1], storageFMT=FMT_DOF )

Initiate CSRMatrix_

    CALL Initiate( obj, &
      & ncol=.tnodes. dofobj, &
      & nrow=.tnodes. dofobj, &
      & idof=dofobj, jdof=dofobj )

Convert CSRMatrix to dense matrix.

    m2 = obj
    CALL Display( m2, "test2" )

Cleanup

    CALL Deallocate( obj )
END PROGRAM main

Initiate(obj, csr, matrixProp)
️܀ See example
↢

We can also initiate the sparse matrix by providing an instance of CSRSparsity.

INTERFACE
  MODULE SUBROUTINE Initiate(obj, csr, matrixProp)
    TYPE(CSRMatrix_), INTENT(INOUT) :: obj
    TYPE(CSRSparsity_), INTENT(IN) :: csr
    !! number of columns in sparse matrix
    !! number of rows in sparse matrix
    !! degree of freedom object; It contains information like
    !! storage format (NODES_FMT, DOF_FMT), and names of physical variable
    !! space-time component in each physical variables
    !! Total number of nodes used for these physical variables
    CHARACTER(LEN=*), OPTIONAL, INTENT(IN) :: MatrixProp
    !! Matrix is `SYM`, `UNSYM`
  END SUBROUTINE Initiate
END INTERFACE

In the above call, CSRSparsity object, csr, should be initiated by the user before passing it to the routine. This is because initiate uses information such as ncol, nrow, nnz stored inside csr.

Interface 3
️܀ See example
↢

We can also pass INT::IA(:), INT:JA(:) and matrix value REAL::A(:) to Initiate() method for constructing the sparse matrix. The interface is given below.

INTERFACE
  MODULE SUBROUTINE Initiate(obj, A, IA, JA, MatrixProp)
    TYPE(CSRMatrix_), INTENT(INOUT) :: obj
    REAL(DFP), INTENT(IN) :: A(:)
    INTEGER(I4B), INTENT(IN) :: IA(:), JA(:)
    CHARACTER(LEN=*), OPTIONAL, INTENT(IN) :: MatrixProp
  END SUBROUTINE Initiate
END INTERFACE

This subroutine will allocate memory for csr, which is an instance of CSRSparsity.

Interface 4
️܀ See example
↢

EASIFEM also provides an assignment operator for copying contents of one sparse matrix into another sparse matrix. The syntax is given below.

INTERFACE
  MODULE SUBROUTINE Initiate(obj, obj2)
    TYPE(CSRMatrix_), INTENT(INOUT) :: obj
    TYPE(CSRMatrix_), INTENT(IN) :: obj2
  END SUBROUTINE Initiate
END INTERFACE

The above call is equivalent to obj=obj2, and it will also copy obj%csr.

Interface 5
️܀ See example
↢

We can also create a csrmatrix from a subset of another csrmatrix.

INTERFACE
  MODULE SUBROUTINE Initiate(obj, obj2, i1, i2, j1, j2)
    TYPE(CSRMatrix_), INTENT(INOUT) :: obj
    TYPE(CSRMatrix_), INTENT(IN) :: obj2
    INTEGER(I4B), INTENT(IN) :: i1, i2
    INTEGER(I4B), INTENT(IN) :: j1, j2
  END SUBROUTINE Initiate
END INTERFACE

Symbolically the above call is equivalent to obj=obj2(i1:i2, j1:j2), and it will allocate memory for obj%csr.

Initiate

Interface​

Interface