find_h_backup Function

public function find_h_backup(a, npart, pos, ndes) result(h)

Uses

    • constants
    • NR
  • proc~~find_h_backup~~UsesGraph proc~find_h_backup find_h_backup NR NR proc~find_h_backup->NR constants constants proc~find_h_backup->constants

Backup method to find the smoothing length via brute force if the optimized method gives 0. It sets the smoothing lengths to the distance between the particle and the ndes-th closest neighbour.

FT 24.11.2021

Arguments

Type IntentOptional Attributes Name
integer, intent(in) :: a

Index of the particle whose smoothing length is to be computed
integer, intent(in) :: npart

Number of particles
double precision, intent(in), DIMENSION(3,npart) :: pos

Array containing particle positions
integer, intent(in) :: ndes

Desired number of neighbours

Return Value double precision

Smoothing length


Called by

proc~~find_h_backup~~CalledByGraph proc~find_h_backup find_h_backup none~place_and_print_ghost_particles place_and_print_ghost_particles none~place_and_print_ghost_particles->proc~find_h_backup proc~compute_and_print_sph_variables compute_and_print_sph_variables proc~compute_and_print_sph_variables->proc~find_h_backup proc~perform_apm perform_apm proc~perform_apm->proc~find_h_backup proc~perform_apm->none~place_and_print_ghost_particles interface~compute_and_print_sph_variables compute_and_print_sph_variables interface~compute_and_print_sph_variables->proc~compute_and_print_sph_variables interface~perform_apm perform_apm interface~perform_apm->proc~perform_apm proc~construct_particles_std construct_particles_std proc~construct_particles_std->interface~perform_apm interface~construct_particles_std construct_particles_std interface~construct_particles_std->proc~construct_particles_std interface~particles particles interface~particles->interface~construct_particles_std program~convergence_test convergence_test program~convergence_test->interface~particles program~sphincs_id sphincs_id program~sphincs_id->interface~particles

Contents

Variables

Source Code

find_h_backup

Variables

Type Visibility Attributes Name Initial
integer, public :: b

Particle index running over all particles, except particle a
double precision, public, DIMENSION(3) :: dist

Distance vector between the particles a and b
double precision, public, DIMENSION(npart) :: dist2

Square norm of the distance vector between the particles a and b

Source Code

  FUNCTION find_h_backup( a, npart, pos, ndes ) RESULT( h )

    !**************************************************************
    !
    !# Backup method to find the smoothing length via brute force
    !  if the optimized method gives 0.
    !  It sets the smoothing lengths to the distance between the
    !  particle and the ndes-th closest neighbour.
    !
    !  FT 24.11.2021
    !
    !**************************************************************

    USE NR,        ONLY: select
    USE constants, ONLY: half

    IMPLICIT NONE

    INTEGER,          INTENT(IN):: a
    !! Index of the particle whose smoothing length is to be computed
    INTEGER,          INTENT(IN):: npart
    !! Number of particles
    INTEGER,          INTENT(IN):: ndes
    !! Desired number of neighbours
    DOUBLE PRECISION, DIMENSION(3,npart), INTENT(IN):: pos
    !! Array containing particle positions

    DOUBLE PRECISION:: h
    !! Smoothing length

    INTEGER:: b
    !! Particle index running over all particles, except particle `a`
    DOUBLE PRECISION, DIMENSION(npart):: dist2
    !! Square norm of the distance vector between the particles `a` and `b`
    DOUBLE PRECISION, DIMENSION(3):: dist
    !! Distance vector between the particles `a` and `b`

    !$OMP PARALLEL DO DEFAULT( NONE ) &
    !$OMP             SHARED( pos, a, npart, dist2 ) &
    !$OMP             PRIVATE( b, dist )
    DO b= 1, npart, 1

      !IF( a /= b )THEN

        dist(:)= pos(:,b) - pos(:,a)
        dist2(b)= DOT_PRODUCT(dist,dist)

      !ENDIF

    ENDDO
    !$OMP END PARALLEL DO

    ! ndes+1 is used, rather tan ndes, because the particle itself is included
    ! in the distance array dist2
    h= half*SQRT( select(ndes+1, npart, dist2) )

  END FUNCTION find_h_backup