./63_bader/inspln.F90

ABINIT/inspln

ABINIT/inspln [ Functions ]

NAME

 inspln

FUNCTION

 This procedure gives the values of the spline coefficients
 (second derivatives) in the 1D grid with periodic boundary
 conditions at rsid - the values of the unknown functions specified
 in the vector valf of direction idir

 Copyright (C) 2002-2017 ABINIT group (PCasek,FF,XG)
 This file is distributed under the terms of the
 GNU General Public License, see ~abinit/COPYING
 or http://www.gnu.org/copyleft/gpl.txt .
 For the initials of contributors, see ~abinit/doc/developers/contributors.txt .

INPUTS

  idir= direction following which the derivatives are evaluated
  snn, tnn=remaining bi-dimensional coordinates of the line along which
        the derivative is to be computed

OUTPUT

  (see side effects)

SIDE EFFECTS

  This routine works on the data contained in the aimfields module

 WARNING
 This file does not follow the ABINIT coding rules (yet)

PARENTS

      initaim

CHILDREN

SOURCE

 40 #if defined HAVE_CONFIG_H
 41 #include "config.h"
 42 #endif
 43 
 44 #include "abi_common.h"
 45 
 46 
 47 subroutine inspln(idir,snn,tnn)
 48 
 49  use m_profiling_abi
 50 
 51  use defs_basis
 52  use defs_aimfields
 53 
 54 !This section has been created automatically by the script Abilint (TD).
 55 !Do not modify the following lines by hand.
 56 #undef ABI_FUNC
 57 #define ABI_FUNC 'inspln'
 58 !End of the abilint section
 59 
 60  implicit none
 61 
 62 !Arguments ------------------------------------
 63 !scalars
 64  integer,intent(in) :: idir,snn,tnn
 65 
 66 !Local variables-------------------------------
 67 !scalars
 68  integer :: dim,ii
 69  real(dp) :: ss
 70 !arrays
 71  real(dp) :: rsid(ngfft(idir)),valf(ngfft(idir))
 72  real(dp),pointer :: ptc(:),ptd(:),ptp(:)
 73 
 74 ! *************************************************************************
 75 
 76 !POINTER INITIALIZATION
 77 
 78  if (idir==1) then
 79    valf(:)=dvl(:,snn,tnn)
 80  elseif (idir==2) then
 81    valf(:)=dvl(tnn,:,snn)
 82  else
 83    valf(:)=dvl(snn,tnn,:)
 84  end if
 85 
 86  nullify(ptd,ptc,ptp)
 87  if(idir==1) then
 88    ptd=>dig1;ptc=>cdig1;ptp=>llg1
 89  elseif (idir==2) then
 90    ptd=>dig2;ptc=>cdig2;ptp=>llg2
 91  else
 92    ptd=>dig3;ptc=>cdig3;ptp=>llg3
 93  end if
 94 
 95  dim=ngfft(idir)
 96 
 97 !FIRST CYCLE OF RECURRENCE
 98 
 99  rsid(1)=valf(2)+valf(dim)-2.*valf(1)
100  rsid(1)=rsid(1)/ptd(1)
101  do ii=2,dim-1
102    rsid(ii)=valf(ii+1)+valf(ii-1)-2.*valf(ii)
103    rsid(ii)=(rsid(ii)-ptc(ii-1)*rsid(ii-1))/ptd(ii)
104  end do
105  ss=0._dp
106  do ii=1,dim-1
107    ss=ss+rsid(ii)*ptp(ii)
108  end do
109  rsid(dim)=valf(1)+valf(dim-1)-2.*valf(dim)
110  rsid(dim)=(rsid(dim)-ss)/ptd(dim)
111 
112 !SECOND CYCLE WITH TRANSPOSED MATRIX
113 
114  rsid(dim)=rsid(dim)/ptd(dim)
115  rsid(dim-1)=(rsid(dim-1)-ptc(dim-1)*rsid(dim))/ptd(dim-1)
116  do ii=dim-2,1,-1
117    rsid(ii)=(rsid(ii)-ptc(ii)*rsid(ii+1)-ptp(ii)*rsid(dim))/ptd(ii)
118  end do
119 
120  if (idir==1) then
121    ddx(:,snn,tnn)=rsid(:)
122  elseif (idir==2) then
123    ddy(tnn,:,snn)=rsid(:)
124  else
125    ddz(snn,tnn,:)=rsid(:)
126  end if
127 
128 end subroutine inspln

TABLE OF CONTENTS

ABINIT/inspln [ Functions ]