GetNptrs_

The GetNptrs_ method is a subroutine version of GetNptrs that retrieves node numbers without allocation. It can return all node numbers, those for a specific mesh ID, or those for specified elements.

Interface

INTERFACE
  MODULE SUBROUTINE GetNptrs1_(obj, ans, tsize)
    CLASS(AbstractMesh_), INTENT(IN) :: obj
    INTEGER(I4B), INTENT(INOUT) :: ans(:)
    INTEGER(I4B), INTENT(OUT) :: tsize
  END SUBROUTINE GetNptrs1_
END INTERFACE

INTERFACE
  MODULE SUBROUTINE GetNptrs2_(obj, meshid, ans, tsize)
    CLASS(AbstractMesh_), INTENT(IN) :: obj
    INTEGER(I4B), INTENT(IN) :: meshid
    INTEGER(I4B), INTENT(INOUT) :: ans(:)
    INTEGER(I4B), INTENT(OUT) :: tsize
  END SUBROUTINE GetNptrs2_
END INTERFACE

INTERFACE
  MODULE SUBROUTINE GetNptrs3_(obj, globalElement, ans, tsize, islocal)
    CLASS(AbstractMesh_), INTENT(IN) :: obj
    INTEGER(I4B), INTENT(IN) :: globalElement(:)
    !! global or local element number
    INTEGER(I4B), INTENT(INOUT) :: ans(:)
    INTEGER(I4B), INTENT(OUT) :: tsize
    LOGICAL(LGT), OPTIONAL, INTENT(IN) :: islocal
    !! if true then globalElement is local
  END SUBROUTINE GetNptrs3_
END INTERFACE

Syntax

! Get all node numbers
CALL mesh%GetNptrs_(ans, tsize)

! Get node numbers for a specific mesh ID
CALL mesh%GetNptrs_(meshid, ans, tsize)

! Get node numbers for specified elements
CALL mesh%GetNptrs_(globalElement, ans, tsize, [islocal])

Parameters

Parameter	Type	Intent	Description
obj	CLASS(AbstractMesh_)	IN	The mesh object
ans	INTEGER(I4B)(:)	INOUT	Array to store the node numbers
tsize	INTEGER(I4B)	OUT	Number of node numbers stored in ans
meshid	INTEGER(I4B)	IN	Mesh ID to filter nodes by
globalElement	INTEGER(I4B)(:)	IN	Global or local element numbers to get nodes from
islocal	LOGICAL(LGT)	IN (optional)	If true, globalElement contains local element numbers

Description

GetNptrs_ retrieves node numbers without allocating new memory. The caller provides a pre-allocated array ans to store the results, and the method returns the actual number of nodes in tsize. This approach is more efficient for repeated operations because it avoids memory allocation overhead.

The method has three versions:

1. Get all node numbers in the mesh
2. Get node numbers for a specific mesh ID
3. Get node numbers for specified elements

Example Usage

TYPE(Mesh_) :: mesh
INTEGER(I4B) :: maxNodes, actualNodes
INTEGER(I4B), ALLOCATABLE :: nodeBuffer(:)

! Initialize mesh...

! Allocate a buffer large enough for any possible result
maxNodes = mesh%GetMaxNodeNumber()
ALLOCATE (nodeBuffer(maxNodes))

! Get all node numbers
CALL mesh%GetNptrs_(nodeBuffer, actualNodes)
PRINT *, "Total nodes:", actualNodes

! Get nodes for a specific mesh ID
CALL mesh%GetNptrs_(meshid=2, ans=nodeBuffer, tsize=actualNodes)
PRINT *, "Nodes in subdomain 2:", actualNodes

! Process only the valid part of the buffer
DO i = 1, actualNodes
  ! Process nodeBuffer(i)
END DO