First attempt at a summation by parts finite differencing thorn.

git-svn-id: https://svn.cct.lsu.edu/repos/numrel/LSUThorns/SummationByParts/trunk@2 f69c4107-0314-4c4f-9ad4-17e986b73f4a

10 files changed, 802 insertions, 0 deletions

diff --git a/README b/README
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--- /dev/null
+++ b/README
@@ -0,0 +1,9 @@
+CVS info   : $Header$
+
+Cactus Code Thorn SummationByParts
+Thorn Author(s)     : Peter Diener <diener@cct.lsu.edu>
+Thorn Maintainer(s) : Peter Diener <diener@cct.lsu.edu>
+--------------------------------------------------------------------------
+
+Purpose of the thorn:
+
diff --git a/doc/documentation.tex b/doc/documentation.tex
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index 0000000..0b64bc1
--- /dev/null
+++ b/doc/documentation.tex
@@ -0,0 +1,144 @@
+% *======================================================================*
+%  Cactus Thorn template for ThornGuide documentation
+%  Author: Ian Kelley
+%  Date: Sun Jun 02, 2002
+%  $Header$
+%
+%  Thorn documentation in the latex file doc/documentation.tex
+%  will be included in ThornGuides built with the Cactus make system.
+%  The scripts employed by the make system automatically include
+%  pages about variables, parameters and scheduling parsed from the
+%  relevant thorn CCL files.
+%
+%  This template contains guidelines which help to assure that your
+%  documentation will be correctly added to ThornGuides. More
+%  information is available in the Cactus UsersGuide.
+%
+%  Guidelines:
+%   - Do not change anything before the line
+%       % START CACTUS THORNGUIDE",
+%     except for filling in the title, author, date, etc. fields.
+%        - Each of these fields should only be on ONE line.
+%        - Author names should be separated with a \\ or a comma.
+%   - You can define your own macros, but they must appear after
+%     the START CACTUS THORNGUIDE line, and must not redefine standard
+%     latex commands.
+%   - To avoid name clashes with other thorns, 'labels', 'citations',
+%     'references', and 'image' names should conform to the following
+%     convention:
+%       ARRANGEMENT_THORN_LABEL
+%     For example, an image wave.eps in the arrangement CactusWave and
+%     thorn WaveToyC should be renamed to CactusWave_WaveToyC_wave.eps
+%   - Graphics should only be included using the graphicx package.
+%     More specifically, with the "\includegraphics" command.  Do
+%     not specify any graphic file extensions in your .tex file. This
+%     will allow us to create a PDF version of the ThornGuide
+%     via pdflatex.
+%   - References should be included with the latex "\bibitem" command.
+%   - Use \begin{abstract}...\end{abstract} instead of \abstract{...}
+%   - Do not use \appendix, instead include any appendices you need as
+%     standard sections.
+%   - For the benefit of our Perl scripts, and for future extensions,
+%     please use simple latex.
+%
+% *======================================================================*
+%
+% Example of including a graphic image:
+%    \begin{figure}[ht]
+% 	\begin{center}
+%    	   \includegraphics[width=6cm]{MyArrangement_MyThorn_MyFigure}
+% 	\end{center}
+% 	\caption{Illustration of this and that}
+% 	\label{MyArrangement_MyThorn_MyLabel}
+%    \end{figure}
+%
+% Example of using a label:
+%   \label{MyArrangement_MyThorn_MyLabel}
+%
+% Example of a citation:
+%    \cite{MyArrangement_MyThorn_Author99}
+%
+% Example of including a reference
+%   \bibitem{MyArrangement_MyThorn_Author99}
+%   {J. Author, {\em The Title of the Book, Journal, or periodical}, 1 (1999),
+%   1--16. {\tt http://www.nowhere.com/}}
+%
+% *======================================================================*
+
+% If you are using CVS use this line to give version information
+% $Header$
+
+\documentclass{article}
+
+% Use the Cactus ThornGuide style file
+% (Automatically used from Cactus distribution, if you have a
+%  thorn without the Cactus Flesh download this from the Cactus
+%  homepage at www.cactuscode.org)
+\usepackage{../../../../doc/latex/cactus}
+
+\begin{document}
+
+% The author of the documentation
+\author{Peter Diener \textless diener@cct.lsu.edu\textgreater}
+
+% The title of the document (not necessarily the name of the Thorn)
+\title{}
+
+% the date your document was last changed, if your document is in CVS,
+% please use:
+%    \date{$ $Date$ $}
+\date{September 29 2004}
+
+\maketitle
+
+% Do not delete next line
+% START CACTUS THORNGUIDE
+
+% Add all definitions used in this documentation here
+%   \def\mydef etc
+
+% Add an abstract for this thorn's documentation
+\begin{abstract}
+
+\end{abstract}
+
+% The following sections are suggestive only.
+% Remove them or add your own.
+
+\section{Introduction}
+
+\section{Physical System}
+
+\section{Numerical Implementation}
+
+\section{Using This Thorn}
+
+\subsection{Obtaining This Thorn}
+
+\subsection{Basic Usage}
+
+\subsection{Special Behaviour}
+
+\subsection{Interaction With Other Thorns}
+
+\subsection{Examples}
+
+\subsection{Support and Feedback}
+
+\section{History}
+
+\subsection{Thorn Source Code}
+
+\subsection{Thorn Documentation}
+
+\subsection{Acknowledgements}
+
+
+\begin{thebibliography}{9}
+
+\end{thebibliography}
+
+% Do not delete next line
+% END CACTUS THORNGUIDE
+
+\end{document}
diff --git a/interface.ccl b/interface.ccl
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--- /dev/null
+++ b/interface.ccl
@@ -0,0 +1,31 @@
+# Interface definition for thorn SummationByParts
+# $Header$
+
+implements: SummationByParts
+inherits: grid
+
+#SUBROUTINE Diff_gf ( CCTK_REAL IN ARRAY var, \
+#                     CCTK_INT IN ni, \
+#                     CCTK_INT IN nj, \
+#                     CCTK_INT IN nk, \
+#                     CCTK_INT IN dir, \
+#                     CCTK_REAL IN delta, \
+#                     CCTK_REAL OUT ARRAY dvar )
+#PROVIDES FUNCTION Diff_gf WITH deriv_gf LANGUAGE Fortran
+
+SUBROUTINE Diff_gf ( CCTK_POINTER IN cctkGH, \
+                     CCTK_INT IN dir, \
+                     CCTK_STRING IN var_name, \
+                     CCTK_STRING IN dvar_name )
+PROVIDES FUNCTION Diff_gf WITH DiffGf LANGUAGE C
+
+CCTK_INT FUNCTION GetDomainSpecification \
+  (CCTK_INT IN size, \
+   CCTK_REAL OUT ARRAY physical_min, \
+   CCTK_REAL OUT ARRAY physical_max, \
+   CCTK_REAL OUT ARRAY interior_min, \
+   CCTK_REAL OUT ARRAY interior_max, \
+   CCTK_REAL OUT ARRAY exterior_min, \
+   CCTK_REAL OUT ARRAY exterior_max, \
+   CCTK_REAL OUT ARRAY spacing)
+USES FUNCTION GetDomainSpecification
diff --git a/param.ccl b/param.ccl
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--- /dev/null
+++ b/param.ccl
@@ -0,0 +1,8 @@
+# Parameter definitions for thorn SummationByParts
+# $Header$
+
+INT order "Order of accuracy" STEERABLE=always
+{
+  2:6 :: ""
+} 2
+
diff --git a/schedule.ccl b/schedule.ccl
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index 0000000..8ebd83a
--- /dev/null
+++ b/schedule.ccl
@@ -0,0 +1,2 @@
+# Schedule definitions for thorn SummationByParts
+# $Header$
diff --git a/src/Derivatives_2_1.F90 b/src/Derivatives_2_1.F90
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+++ b/src/Derivatives_2_1.F90
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+#include "cctk.h"
+#include "cctk_Functions.h"
+#include "cctk_Parameters.h"
+
+subroutine deriv_gf_2_1 ( var, ni, nj, nk, dir, bb, gsize, delta, dvar )
+
+  implicit none
+
+  DECLARE_CCTK_FUNCTIONS
+  DECLARE_CCTK_PARAMETERS
+
+  CCTK_REAL, parameter :: zero = 0.0
+  integer, parameter :: wp = kind(zero)
+  CCTK_INT, intent(IN) :: ni, nj, nk
+  CCTK_REAL, dimension(ni,nj,nk), intent(IN) :: var
+  CCTK_INT, intent(IN) :: dir
+  CCTK_INT, intent(IN) :: bb(2)
+  CCTK_INT, intent(IN) :: gsize
+  CCTK_REAL, intent(IN) :: delta
+  CCTK_REAL, dimension(ni,nj,nk), intent(OUT) :: dvar
+
+  CCTK_REAL, dimension(1), save :: a
+  CCTK_REAL, dimension(3,2), save :: q 
+  CCTK_REAL :: idel
+
+  CCTK_INT :: il, ir, jl, jr, kl, kr
+
+  logical, save :: first = .true.
+
+  if ( first ) then
+    a(1) = 1.0_wp/2.0_wp
+
+    q(1,1) = -1.0_wp; q(2,1) = 1.0_wp; q(3,1) = zero
+    q(1,2) = -1.0_wp/2.0_wp; q(2,2) = zero; q(3,2) = 1.0_wp/2.0_wp
+    first = .false.
+  end if
+
+  idel = 1.0_wp / delta
+
+  direction: select case (dir)
+  case (0) direction
+    if ( bb(1) == 0 ) then
+      il = 1 + gsize
+    else
+      dvar(1,:,:) = ( q(1,1) * var(1,:,:) + q(2,1) * var(2,:,:) ) * idel
+      dvar(2,:,:) = ( q(1,2) * var(1,:,:) + q(3,2) * var(3,:,:) ) * idel
+      il = 3
+    end if
+    if ( bb(2) == 0 ) then
+      ir = ni - gsize
+    else
+      dvar(ni-1,:,:) = - ( q(1,2) * var(ni,:,:) + &
+                           q(3,2) * var(ni-2,:,:) ) * idel
+      dvar(ni,:,:) = - ( q(1,1) * var(ni,:,:) + &
+                         q(2,1) * var(ni-1,:,:) ) * idel
+      ir = ni - 2
+    end if
+    dvar(il:ir,:,:) = a(1) * ( var(il+1:ir+1,:,:) - var(il-1:ir-1,:,:) ) * idel
+  case (1) direction
+    if ( bb(1) == 0 ) then
+      jl = 1 + gsize
+    else
+      dvar(:,1,:) = ( q(1,1) * var(:,1,:) + q(2,1) * var(:,2,:) ) * idel
+      dvar(:,2,:) = ( q(1,2) * var(:,1,:) + q(3,2) * var(:,3,:) ) * idel
+      jl = 3
+    end if
+    if ( bb(2) == 0 ) then
+      jr = nj - gsize
+    else
+      dvar(:,nj-1,:) = - ( q(1,2) * var(:,nj,:) + &
+                           q(3,2) * var(:,nj-2,:) ) * idel
+      dvar(:,nj,:) = - ( q(1,1) * var(:,nj,:) + &
+                         q(2,1) * var(:,nj-1,:) ) * idel
+      jr = nj - 2
+    end if
+    dvar(:,jl:jr,:) = a(1) * ( var(:,jl+1:jr+1,:) - var(:,jl-1:jr-1,:) ) * idel
+  case (2) direction
+    if ( bb(1) == 0 ) then
+      kl = 1 + gsize
+    else
+      dvar(:,:,1) = ( q(1,1) * var(:,:,1) + q(2,1) * var(:,:,2) ) * idel
+      dvar(:,:,2) = ( q(1,2) * var(:,:,1) + q(3,2) * var(:,:,3) ) * idel
+      kl = 3
+    end if
+    if ( bb(2) == 0 ) then
+      kr = nk - gsize
+    else 
+      dvar(:,:,nk-1) = - ( q(1,2) * var(:,:,nk) + &
+                           q(3,2) * var(:,:,nk-2) ) * idel
+      dvar(:,:,nk) = - ( q(1,1) * var(:,:,nk) + &
+                         q(2,1) * var(:,:,nk-1) ) * idel
+      kr = nk - 2
+    end if
+    dvar(:,:,kl:kr) = a(1) * ( var(:,:,kl+1:kr+1) - var(:,:,kl-1:kr-1) ) * idel
+  end select direction
+end subroutine deriv_gf_2_1
diff --git a/src/Derivatives_4_2.F90 b/src/Derivatives_4_2.F90
new file mode 100644
index 0000000..ec56613
--- /dev/null
+++ b/src/Derivatives_4_2.F90
@@ -0,0 +1,160 @@
+#include "cctk.h"
+#include "cctk_Functions.h"
+#include "cctk_Parameters.h"
+
+subroutine deriv_gf_4_2 ( var, ni, nj, nk, dir, bb, gsize, delta, dvar )
+
+  implicit none
+
+  DECLARE_CCTK_FUNCTIONS
+  DECLARE_CCTK_PARAMETERS
+
+  CCTK_REAL, parameter :: zero = 0.0
+  integer, parameter :: wp = kind(zero)
+  CCTK_INT, intent(IN) :: ni, nj, nk
+  CCTK_REAL, dimension(ni,nj,nk), intent(IN) :: var
+  CCTK_INT, intent(IN) :: dir
+  CCTK_INT, intent(IN) :: bb(2)
+  CCTK_INT, intent(IN) :: gsize
+  CCTK_REAL, intent(IN) :: delta
+  CCTK_REAL, dimension(ni,nj,nk), intent(OUT) :: dvar
+
+  CCTK_REAL, dimension(2), save :: a
+  CCTK_REAL, dimension(6,4), save :: q 
+  CCTK_REAL :: idel
+
+  CCTK_INT :: il, ir, jl, jr, kl, kr
+
+  logical, save :: first = .true.
+
+  if ( first ) then
+    a(1) = 2.0_wp/3.0_wp; a(2) = -1.0_wp/12.0_wp
+
+    q(1,1) = -24.0_wp/17.0_wp; q(2,1) = 59.0_wp/34.0_wp
+    q(3,1) = -4.0_wp/17.0_wp; q(4,1) = -3.0_wp/34.0_wp
+    q(5,1) = zero; q(6,1) = zero
+    q(1,2) = -1.0_wp/2.0_wp; q(2,2) = zero
+    q(3,2) = 1.0_wp/2.0_wp; q(4,2) = zero
+    q(5,2) = zero; q(6,2) = zero
+    q(1,3) = 4.0_wp/43.0_wp; q(2,3) = -59.0_wp/86.0_wp
+    q(3,3) = zero; q(4,3) = 59.0_wp/86.0_wp
+    q(5,3) = -4.0_wp/43.0_wp; q(6,3) = zero
+    q(1,4) = 3.0_wp/98.0_wp; q(2,4) = zero
+    q(3,4) = -59.0_wp/98.0_wp; q(4,4) = zero
+    q(5,4) = 32.0_wp/49.0_wp; q(6,4) = -4.0_wp/49.0_wp
+    first = .false.
+  end if
+
+  idel = 1.0_wp / delta
+
+  direction: select case (dir)
+  case (0) direction
+    if ( bb(1) == 0 ) then
+      il = 1 + gsize
+    else
+      dvar(1,:,:) = ( q(1,1) * var(1,:,:) + q(2,1) * var(2,:,:)  + &
+                      q(3,1) * var(3,:,:) + q(4,1) * var(4,:,:) ) * idel
+      dvar(2,:,:) = ( q(1,2) * var(1,:,:) + q(3,2) * var(3,:,:) ) * idel
+      dvar(3,:,:) = ( q(1,3) * var(1,:,:) + q(2,3) * var(2,:,:) + &
+                      q(4,3) * var(4,:,:) + q(5,3) * var(5,:,:) ) * idel
+      dvar(4,:,:) = ( q(1,4) * var(1,:,:) + q(3,4) * var(3,:,:) + &
+                      q(5,4) * var(5,:,:) + q(6,4) * var(6,:,:) ) * idel
+      il = 5
+    end if
+    if ( bb(2) == 0 ) then
+      ir = ni - gsize
+    else
+      dvar(ni-3,:,:) = - ( q(1,4) * var(ni,:,:) + &
+                           q(3,4) * var(ni-2,:,:) + &
+                           q(5,4) * var(ni-4,:,:) + &
+                           q(6,4) * var(ni-5,:,:) ) * idel
+      dvar(ni-2,:,:) = - ( q(1,3) * var(ni,:,:) + &
+                           q(2,3) * var(ni-1,:,:) + &
+                           q(4,3) * var(ni-3,:,:) + &
+                           q(5,3) * var(ni-4,:,:) ) * idel
+      dvar(ni-1,:,:) = - ( q(1,2) * var(ni,:,:) + &
+                           q(3,2) * var(ni-2,:,:) ) * idel
+      dvar(ni,:,:)   = - ( q(1,1) * var(ni,:,:) + &
+                           q(2,1) * var(ni-1,:,:) + &
+                           q(3,1) * var(ni-2,:,:) + &
+                           q(4,1) * var(ni-3,:,:) ) * idel
+      ir = ni - 4
+    end if
+    dvar(il:ir,:,:) = ( a(1) * ( var(il+1:ir+1,:,:) - &
+                                 var(il-1:ir-1,:,:) ) + &
+                        a(2) * ( var(il+2:ir+2,:,:) - &
+                                 var(il-2:ir-2,:,:) ) ) * idel
+  case (1) direction
+    if ( bb(1) == 0 ) then
+      jl = 1 + gsize
+    else
+      dvar(:,1,:) = ( q(1,1) * var(:,1,:) + q(2,1) * var(:,2,:)  + &
+                      q(3,1) * var(:,3,:) + q(4,1) * var(:,4,:) ) * idel
+      dvar(:,2,:) = ( q(1,2) * var(:,1,:) + q(3,2) * var(:,3,:) ) * idel
+      dvar(:,3,:) = ( q(1,3) * var(:,1,:) + q(2,3) * var(:,2,:) + &
+                      q(4,3) * var(:,4,:) + q(5,3) * var(:,5,:) ) * idel
+      dvar(:,4,:) = ( q(1,4) * var(:,1,:) + q(3,4) * var(:,3,:) + &
+                      q(5,4) * var(:,5,:) + q(6,4) * var(:,6,:) ) * idel
+      jl = 5
+    end if
+    if ( bb(2) == 0 ) then
+      jr = nj - gsize
+    else
+      dvar(:,nj-3,:) = - ( q(1,4) * var(:,nj,:) + &
+                           q(3,4) * var(:,nj-2,:) + &
+                           q(5,4) * var(:,nj-4,:) + &
+                           q(6,4) * var(:,nj-5,:) ) * idel
+      dvar(:,nj-2,:) = - ( q(1,3) * var(:,nj,:) + &
+                           q(2,3) * var(:,nj-1,:) + &
+                           q(4,3) * var(:,nj-3,:) + &
+                           q(5,3) * var(:,nj-4,:) ) * idel
+      dvar(:,nj-1,:) = - ( q(1,2) * var(:,nj,:) + &
+                           q(3,2) * var(:,nj-2,:) ) * idel
+      dvar(:,nj,:)   = - ( q(1,1) * var(:,nj,:) + &
+                           q(2,1) * var(:,nj-1,:) + &
+                           q(3,1) * var(:,nj-2,:) + &
+                           q(4,1) * var(:,nj-3,:) ) * idel
+      jr = nj - 4
+    end if
+    dvar(:,jl:jr,:) = ( a(1) * ( var(:,jl+1:jr+1,:) - &
+                                 var(:,jl-1:jr-1,:) ) + &
+                        a(2) * ( var(:,jl+2:jr+2,:) - &
+                                 var(:,jl-2:jr-2,:) ) ) * idel
+  case (2) direction
+    if ( bb(1) == 0 ) then
+      kl = 1 + gsize
+    else
+      dvar(:,:,1) = ( q(1,1) * var(:,:,1) + q(2,1) * var(:,:,2)  + &
+                      q(3,1) * var(:,:,3) + q(4,1) * var(:,:,4) ) * idel
+      dvar(:,:,2) = ( q(1,2) * var(:,:,1) + q(3,2) * var(:,:,3) ) * idel
+      dvar(:,:,3) = ( q(1,3) * var(:,:,1) + q(2,3) * var(:,:,2) + &
+                      q(4,3) * var(:,:,4) + q(5,3) * var(:,:,5) ) * idel
+      dvar(:,:,4) = ( q(1,4) * var(:,:,1) + q(3,4) * var(:,:,3) + &
+                      q(5,4) * var(:,:,5) + q(6,4) * var(:,:,6) ) * idel
+      kl = 5
+    end if
+    if ( bb(2) == 0 ) then
+      kr = nk - gsize
+    else 
+      dvar(:,:,nk-3) = - ( q(1,4) * var(:,:,nk) + &
+                           q(3,4) * var(:,:,nk-2) + &
+                           q(5,4) * var(:,:,nk-4) + &
+                           q(6,4) * var(:,:,nk-5) ) * idel
+      dvar(:,:,nk-2) = - ( q(1,3) * var(:,:,nk) + &
+                           q(2,3) * var(:,:,nk-1) + &
+                           q(4,3) * var(:,:,nk-3) + &
+                           q(5,3) * var(:,:,nk-4) ) * idel
+      dvar(:,:,nk-1) = - ( q(1,2) * var(:,:,nk) + &
+                           q(3,2) * var(:,:,nk-2) ) * idel
+      dvar(:,:,nk)   = - ( q(1,1) * var(:,:,nk) + &
+                           q(2,1) * var(:,:,nk-1) + &
+                           q(3,1) * var(:,:,nk-2) + &
+                           q(4,1) * var(:,:,nk-3) ) * idel
+      kr = nk - 4
+    end if
+    dvar(:,:,kl:kr) = ( a(1) * ( var(:,:,kl+1:kr+1) - &
+                                 var(:,:,kl-1:kr-1) ) + &
+                        a(2) * ( var(:,:,kl+2:kr+2) - &
+                                 var(:,:,kl-2:kr-2) ) ) * idel
+  end select direction
+end subroutine deriv_gf_4_2
diff --git a/src/Derivatives_6_3.F90 b/src/Derivatives_6_3.F90
new file mode 100644
index 0000000..3da882d
--- /dev/null
+++ b/src/Derivatives_6_3.F90
@@ -0,0 +1,239 @@
+#include "cctk.h"
+#include "cctk_Functions.h"
+#include "cctk_Parameters.h"
+
+subroutine deriv_gf_6_3 ( var, ni, nj, nk, dir, bb, gsize, delta, dvar )
+
+  implicit none
+
+  DECLARE_CCTK_FUNCTIONS
+  DECLARE_CCTK_PARAMETERS
+
+  CCTK_REAL, parameter :: zero = 0.0
+  integer, parameter :: wp = kind(zero)
+  CCTK_INT, intent(IN) :: ni, nj, nk
+  CCTK_REAL, dimension(ni,nj,nk), intent(IN) :: var
+  CCTK_INT, intent(IN) :: dir
+  CCTK_INT, intent(IN) :: bb(2)
+  CCTK_INT, intent(IN) :: gsize
+  CCTK_REAL, intent(IN) :: delta
+  CCTK_REAL, dimension(ni,nj,nk), intent(OUT) :: dvar
+
+  CCTK_REAL, dimension(3), save :: a
+  CCTK_REAL, dimension(9,6), save :: q 
+  CCTK_REAL :: idel
+
+  CCTK_INT :: il, ir, jl, jr, kl, kr
+
+  logical, save :: first = .true.
+
+  if ( first ) then
+    a(1) = 3.0_wp/4.0_wp; a(2) = -3.0_wp/20.0_wp; a(3) = 1.0_wp/60.0_wp
+
+    q(1,1) = -21600.0_wp/13649.0_wp; q(2,1) = 81763.0_wp/40947.0_wp
+    q(3,1) = 131.0_wp/27298.0_wp; q(4,1) = -9143.0_wp/13649.0_wp
+    q(5,1) = 20539.0_wp/81894.0_wp; q(6,1) = zero;
+    q(7,1) = zero; q(8,1) = zero; q(9,1) = zero
+    q(1,2) = -81763.0_wp/180195.0_wp; q(2,2) = zero
+    q(3,2) = 7357.0_wp/36039.0_wp; q(4,2) = 30637.0_wp/72078.0_wp
+    q(5,2) = -2328.0_wp/12013.0_wp; q(6,2) = 6611.0_wp/360390.0_wp
+    q(7,2) = zero; q(8,2) = zero; q(9,2) = zero
+    q(1,3) = -131.0_wp/54220.0_wp; q(2,3) = -7357.0_wp/16266.0_wp
+    q(3,3) = zero; q(4,3) = 645.0_wp/2711.0_wp
+    q(5,3) = 11237.0_wp/32532.0_wp; q(6,3) = -3487.0_wp/27110.0_wp
+    q(7,3) = zero; q(8,3) = zero; q(9,3) = zero
+    q(1,4) = 9143.0_wp/53590.0_wp; q(2,4) = -30637.0_wp/64308.0_wp
+    q(3,4) =  -645.0_wp/5359.0_wp; q(4,4) = zero
+    q(5,4) = 13733.0_wp/32154.0_wp; q(6,4) = -67.0_wp/4660.0_wp
+    q(7,4) = 72.0_wp/5359.0_wp; q(8,4) = zero; q(9,4) = zero;
+    q(1,5) = -20539.0_wp/236310.0_wp; q(2,5) = 2328.0_wp/7877.0_wp
+    q(3,5) = -11237.0_wp/47262.0_wp; q(4,5) = -13733.0_wp/23631.0_wp
+    q(5,5) = zero; q(6,5) = 89387.0_wp/118155.0_wp
+    q(7,5) = -1296.0_wp/7877.0_wp; q(8,5) = 144.0_wp/7877.0_wp; q(9,5) = zero
+    q(1,6) = zero; q(2,6) = -6611.0_wp/262806.0_wp
+    q(3,6) = 3487.0_wp/43801.0_wp; q(4,6) = 1541.0_wp/87602.0_wp
+    q(5,6) = -89387.0_wp/131403.0_wp; q(6,6) = zero
+    q(7,6) = 32400.0_wp/43801.0_wp; q(8,6) = -6480.0_wp/43801.0_wp
+    q(9,6) = 720.0_wp/43801.0_wp
+    first = .false. 
+  end if
+
+  idel = 1.0_wp / delta
+
+  direction: select case (dir)
+  case (0) direction
+    if ( bb(1) == 0 ) then
+      il = 1 + gsize
+    else
+      dvar(1,:,:) = ( q(1,1) * var(1,:,:) + q(2,1) * var(2,:,:) + &
+                      q(3,1) * var(3,:,:) + q(4,1) * var(4,:,:) + &
+                      q(5,1) * var(5,:,:) ) * idel
+      dvar(2,:,:) = ( q(1,2) * var(1,:,:) + q(3,2) * var(3,:,:) + &
+                      q(4,2) * var(4,:,:) + q(5,2) * var(5,:,:) + &
+                      q(6,2) * var(6,:,:) ) * idel
+      dvar(3,:,:) = ( q(1,3) * var(1,:,:) + q(2,3) * var(2,:,:) + &
+                      q(4,3) * var(4,:,:) + q(5,3) * var(5,:,:) + &
+                      q(6,3) * var(6,:,:) ) * idel
+      dvar(4,:,:) = ( q(1,4) * var(1,:,:) + q(2,4) * var(2,:,:) + &
+                      q(3,4) * var(3,:,:) + q(5,4) * var(5,:,:) + &
+                      q(6,4) * var(6,:,:) + q(7,4) * var(7,:,:) ) * idel
+      dvar(5,:,:) = ( q(1,5) * var(1,:,:) + q(2,5) * var(2,:,:) + &
+                      q(3,5) * var(3,:,:) + q(4,5) * var(4,:,:) + &
+                      q(6,5) * var(6,:,:) + q(7,5) * var(7,:,:) + &
+                      q(8,5) * var(8,:,:) ) * idel
+      dvar(6,:,:) = ( q(2,6) * var(2,:,:) + q(3,6) * var(3,:,:) + &
+                      q(4,6) * var(4,:,:) + q(5,6) * var(5,:,:) + &
+                      q(7,6) * var(7,:,:) + q(8,6) * var(8,:,:) + &
+                      q(9,6) * var(9,:,:) ) * idel
+      il = 7
+    end if
+    if ( bb(2) == 0 ) then
+      ir = ni - gsize
+    else
+      dvar(ni,:,:) =   - ( q(1,1) * var(ni,:,:) + q(2,1) * var(ni-1,:,:) + &
+                           q(3,1) * var(ni-2,:,:) + q(4,1) * var(ni-3,:,:) + &
+                           q(5,1) * var(ni-4,:,:) ) * idel
+      dvar(ni-1,:,:) = - ( q(1,2) * var(ni,:,:) + q(3,2) * var(ni-2,:,:) + &
+                           q(4,2) * var(ni-3,:,:) + q(5,2) * var(ni-4,:,:) + &
+                           q(6,2) * var(ni-5,:,:) ) * idel
+      dvar(ni-2,:,:) = - ( q(1,3) * var(ni,:,:) + q(2,3) * var(ni-1,:,:) + &
+                           q(4,3) * var(ni-3,:,:) + q(5,3) * var(ni-4,:,:) + &
+                           q(6,3) * var(ni-5,:,:) ) * idel
+      dvar(ni-3,:,:) = - ( q(1,4) * var(ni,:,:) + q(2,4) * var(ni-1,:,:) + &
+                           q(3,4) * var(ni-2,:,:) + q(5,4) * var(ni-4,:,:) + &
+                           q(6,4) * var(ni-5,:,:) + &
+                           q(7,4) * var(ni-6,:,:) ) * idel
+      dvar(ni-4,:,:) = - ( q(1,5) * var(ni,:,:) + q(2,5) * var(ni-1,:,:) + &
+                           q(3,5) * var(ni-2,:,:) + q(4,5) * var(ni-3,:,:) + &
+                           q(6,5) * var(ni-5,:,:) + q(7,5) * var(ni-6,:,:) + &
+                           q(8,5) * var(ni-7,:,:) ) * idel
+      dvar(ni-5,:,:) = - ( q(2,6) * var(ni-1,:,:) + q(3,6) * var(ni-2,:,:) + &
+                           q(4,6) * var(ni-3,:,:) + q(5,6) * var(ni-4,:,:) + &
+                           q(7,6) * var(ni-6,:,:) + q(8,6) * var(ni-7,:,:) + &
+                           q(9,6) * var(ni-8,:,:) ) * idel
+      ir = ni - 6
+    end if
+    dvar(il:ir,:,:) = ( a(1) * ( var(il+1:ir+1,:,:) - &
+                                 var(il-1:ir-1,:,:) ) + &
+                        a(2) * ( var(il+2:ir+2,:,:) - &
+                                 var(il-2:ir-2,:,:) ) + &
+                        a(3) * ( var(il+3:ir+3,:,:) - &
+                                 var(il-3:ir-3,:,:) ) ) * idel
+  case (1) direction
+    if ( bb(1) == 0 ) then
+      jl = 1 + gsize
+    else
+      dvar(:,1,:) = ( q(1,1) * var(:,1,:) + q(2,1) * var(:,2,:) + &
+                      q(3,1) * var(:,3,:) + q(4,1) * var(:,4,:) + &
+                      q(5,1) * var(:,5,:) ) * idel
+      dvar(:,2,:) = ( q(1,2) * var(:,1,:) + q(3,2) * var(:,3,:) + &
+                      q(4,2) * var(:,4,:) + q(5,2) * var(:,5,:) + &
+                      q(6,2) * var(:,6,:) ) * idel
+      dvar(:,3,:) = ( q(1,3) * var(:,1,:) + q(2,3) * var(:,2,:) + &
+                      q(4,3) * var(:,4,:) + q(5,3) * var(:,5,:) + &
+                      q(6,3) * var(:,6,:) ) * idel
+      dvar(:,4,:) = ( q(1,4) * var(:,1,:) + q(2,4) * var(:,2,:) + &
+                      q(3,4) * var(:,3,:) + q(5,4) * var(:,5,:) + &
+                      q(6,4) * var(:,6,:) + q(7,4) * var(:,7,:) ) * idel
+      dvar(:,5,:) = ( q(1,5) * var(:,1,:) + q(2,5) * var(:,2,:) + &
+                      q(3,5) * var(:,3,:) + q(4,5) * var(:,4,:) + &
+                      q(6,5) * var(:,6,:) + q(7,5) * var(:,7,:) + &
+                      q(8,5) * var(:,8,:) ) * idel
+      dvar(:,6,:) = ( q(2,6) * var(:,2,:) + q(3,6) * var(:,3,:) + &
+                      q(4,6) * var(:,4,:) + q(5,6) * var(:,5,:) + &
+                      q(7,6) * var(:,7,:) + q(8,6) * var(:,8,:) + &
+                      q(9,6) * var(:,9,:) ) * idel
+      jl = 7
+    end if
+    if ( bb(2) == 0 ) then
+      jr = nj - gsize
+    else
+      dvar(:,nj,:) =   - ( q(1,1) * var(:,nj,:) + q(2,1) * var(:,nj-1,:) + &
+                           q(3,1) * var(:,nj-2,:) + q(4,1) * var(:,nj-3,:) + &
+                           q(5,1) * var(:,nj-4,:) ) * idel
+      dvar(:,nj-1,:) = - ( q(1,2) * var(:,nj,:) + q(3,2) * var(:,nj-2,:) + &
+                           q(4,2) * var(:,nj-3,:) + q(5,2) * var(:,nj-4,:) + &
+                           q(6,2) * var(:,nj-5,:) ) * idel
+      dvar(:,nj-2,:) = - ( q(1,3) * var(:,nj,:) + q(2,3) * var(:,nj-1,:) + &
+                           q(4,3) * var(:,nj-3,:) + q(5,3) * var(:,nj-4,:) + &
+                           q(6,3) * var(:,nj-5,:) ) * idel
+      dvar(:,nj-3,:) = - ( q(1,4) * var(:,nj,:) + q(2,4) * var(:,nj-1,:) + &
+                           q(3,4) * var(:,nj-2,:) + q(5,4) * var(:,nj-4,:) + &
+                           q(6,4) * var(:,nj-5,:) + &
+                           q(7,4) * var(:,nj-6,:) ) * idel
+      dvar(:,nj-4,:) = - ( q(1,5) * var(:,nj,:) + q(2,5) * var(:,nj-1,:) + &
+                           q(3,5) * var(:,nj-2,:) + q(4,5) * var(:,nj-3,:) + &
+                           q(6,5) * var(:,nj-5,:) + q(7,5) * var(:,nj-6,:) + &
+                           q(8,5) * var(:,nj-7,:) ) * idel
+      dvar(:,nj-5,:) = - ( q(2,6) * var(:,nj-1,:) + q(3,6) * var(:,nj-2,:) + &
+                           q(4,6) * var(:,nj-3,:) + q(5,6) * var(:,nj-4,:) + &
+                           q(7,6) * var(:,nj-6,:) + q(8,6) * var(:,nj-7,:) + &
+                           q(9,6) * var(:,nj-8,:) ) * idel
+      jr = nj - 6
+    end if
+    dvar(:,jl:jr,:) = ( a(1) * ( var(:,jl+1:jr+1,:) - &
+                                 var(:,jl-1:jr-1,:) ) + &
+                        a(2) * ( var(:,jl+2:jr+2,:) - &
+                                 var(:,jl-2:jr-2,:) ) + &
+                        a(3) * ( var(:,jl+3:jr+3,:) - &
+                                 var(:,jl-3:jr-3,:) ) ) * idel
+  case (2) direction
+    if ( bb(1) == 0 ) then
+      kl = 1 + gsize
+    else
+      dvar(:,:,1) = ( q(1,1) * var(:,:,1) + q(2,1) * var(:,:,2) + &
+                      q(3,1) * var(:,:,3) + q(4,1) * var(:,:,4) + &
+                      q(5,1) * var(:,:,5) ) * idel
+      dvar(:,:,2) = ( q(1,2) * var(:,:,1) + q(3,2) * var(:,:,3) + &
+                      q(4,2) * var(:,:,4) + q(5,2) * var(:,:,5) + &
+                      q(6,2) * var(:,:,6) ) * idel
+      dvar(:,:,3) = ( q(1,3) * var(:,:,1) + q(2,3) * var(:,:,2) + &
+                      q(4,3) * var(:,:,4) + q(5,3) * var(:,:,5) + &
+                      q(6,3) * var(:,:,6) ) * idel
+      dvar(:,:,4) = ( q(1,4) * var(:,:,1) + q(2,4) * var(:,:,2) + &
+                      q(3,4) * var(:,:,3) + q(5,4) * var(:,:,5) + &
+                      q(6,4) * var(:,:,6) + q(7,4) * var(:,:,7) ) * idel
+      dvar(:,:,5) = ( q(1,5) * var(:,:,1) + q(2,5) * var(:,:,2) + &
+                      q(3,5) * var(:,:,3) + q(4,5) * var(:,:,4) + &
+                      q(6,5) * var(:,:,6) + q(7,5) * var(:,:,7) + &
+                      q(8,5) * var(:,:,8) ) * idel
+      dvar(:,:,6) = ( q(2,6) * var(:,:,2) + q(3,6) * var(:,:,3) + &
+                      q(4,6) * var(:,:,4) + q(5,6) * var(:,:,5) + &
+                      q(7,6) * var(:,:,7) + q(8,6) * var(:,:,8) + &
+                      q(9,6) * var(:,:,9) ) * idel
+      kl = 7
+    end if
+    if ( bb(2) == 0 ) then
+      kr = nk - gsize
+    else 
+      dvar(:,:,nk) =   - ( q(1,1) * var(:,:,nk) + q(2,1) * var(:,:,nk-1) + &
+                           q(3,1) * var(:,:,nk-2) + q(4,1) * var(:,:,nk-3) + &
+                           q(5,1) * var(:,:,nk-4) ) * idel
+      dvar(:,:,nk-1) = - ( q(1,2) * var(:,:,nk) + q(3,2) * var(:,:,nk-2) + &
+                           q(4,2) * var(:,:,nk-3) + q(5,2) * var(:,:,nk-4) + &
+                           q(6,2) * var(:,:,nk-5) ) * idel
+      dvar(:,:,nk-2) = - ( q(1,3) * var(:,:,nk) + q(2,3) * var(:,:,nk-1) + &
+                           q(4,3) * var(:,:,nk-3) + q(5,3) * var(:,:,nk-4) + &
+                           q(6,3) * var(:,:,nk-5) ) * idel
+      dvar(:,:,nk-3) = - ( q(1,4) * var(:,:,nk) + q(2,4) * var(:,:,nk-1) + &
+                           q(3,4) * var(:,:,nk-2) + q(5,4) * var(:,:,nk-4) + &
+                           q(6,4) * var(:,:,nk-5) + &
+                           q(7,4) * var(:,:,nk-6) ) * idel
+      dvar(:,:,nk-4) = - ( q(1,5) * var(:,:,nk) + q(2,5) * var(:,:,nk-1) + &
+                           q(3,5) * var(:,:,nk-2) + q(4,5) * var(:,:,nk-3) + &
+                           q(6,5) * var(:,:,nk-5) + q(7,5) * var(:,:,nk-6) + &
+                           q(8,5) * var(:,:,nk-7) ) * idel
+      dvar(:,:,nk-5) = - ( q(2,6) * var(:,:,nk-1) + q(3,6) * var(:,:,nk-2) + &
+                           q(4,6) * var(:,:,nk-3) + q(5,6) * var(:,:,nk-4) + &
+                           q(7,6) * var(:,:,nk-6) + q(8,6) * var(:,:,nk-7) + &
+                           q(9,6) * var(:,:,nk-8) ) * idel
+      kr = nk - 6
+    end if
+    dvar(:,:,kl:kr) = ( a(1) * ( var(:,:,kl+1:kr+1) - &
+                                 var(:,:,kl-1:kr-1) ) + &
+                        a(2) * ( var(:,:,kl+2:kr+2) - &
+                                 var(:,:,kl-2:kr-2) ) + &
+                        a(3) * ( var(:,:,kl+3:kr+3) - &
+                                 var(:,:,kl-3:kr-3) ) ) * idel
+  end select direction
+end subroutine deriv_gf_6_3
diff --git a/src/call_derivs.c b/src/call_derivs.c
new file mode 100644
index 0000000..c696e4e
--- /dev/null
+++ b/src/call_derivs.c
@@ -0,0 +1,105 @@
+#include "cctk.h"
+#include "cctk_Parameters.h"
+
+#include <assert.h>
+
+void DiffGf ( const CCTK_POINTER cctkGH, const CCTK_INT dir,
+              const char *var_name, const char *dvar_name )
+{
+  CCTK_REAL *var, *dvar;
+  CCTK_INT ni, nj, nk, gsize, ic;
+  CCTK_REAL delta;
+  CCTK_REAL phys_min[3], phys_max[3];
+  CCTK_REAL int_min[3], int_max[3];
+  CCTK_REAL ext_min[3], ext_max[3];
+  CCTK_REAL spacing[3];
+  CCTK_INT ierr;
+  CCTK_INT lsh[3], bbox[6], bb[2], nghostzones[3];
+  void CCTK_FCALL CCTK_FNAME(deriv_gf_2_1)(CCTK_REAL *var, const CCTK_INT *ni,
+                                       const CCTK_INT *nj, const CCTK_INT *nk,
+                                       const CCTK_INT *dir,
+                                       const CCTK_INT *bb,
+                                       const CCTK_INT *gsize,
+                                       const CCTK_REAL *delta,
+                                       CCTK_REAL *dvar);
+  void CCTK_FCALL CCTK_FNAME(deriv_gf_4_2)(CCTK_REAL *var, const CCTK_INT *ni,
+                                       const CCTK_INT *nj, const CCTK_INT *nk,
+                                       const CCTK_INT *dir,
+                                       const CCTK_INT *bb,
+                                       const CCTK_INT *gsize,
+                                       const CCTK_REAL *delta,
+                                       CCTK_REAL *dvar);
+  void CCTK_FCALL CCTK_FNAME(deriv_gf_6_3)(CCTK_REAL *var, const CCTK_INT *ni,
+                                       const CCTK_INT *nj, const CCTK_INT *nk,
+                                       const CCTK_INT *dir,
+                                       const CCTK_INT *bb,
+                                       const CCTK_INT *gsize,
+                                       const CCTK_REAL *delta,
+                                       CCTK_REAL *dvar);
+  DECLARE_CCTK_PARAMETERS
+
+  
+  if (CCTK_GrouplshVN(cctkGH, 3, lsh, var_name) < 0)
+  {
+    CCTK_VWarn(1, __LINE__, __FILE__, CCTK_THORNSTRING,
+               "Error getting local size of grid for variable '%s'",var_name);
+  }
+  if (CCTK_GroupbboxVN(cctkGH, 6, bbox, var_name) < 0)
+  {
+    CCTK_VWarn(1, __LINE__, __FILE__, CCTK_THORNSTRING,
+               "Error getting bounding box for variable '%s'",var_name);
+  }
+  if (CCTK_GroupnghostzonesVN(cctkGH, 3, nghostzones, var_name) < 0)
+  {
+    CCTK_VWarn(1, __LINE__, __FILE__, CCTK_THORNSTRING,
+               "Error getting number of ghostzones for variable '%s'",var_name);
+  }
+
+  ni = lsh[0]; nj = lsh[1]; nk = lsh[2];
+
+  ierr = GetDomainSpecification ( 3, phys_min, phys_max, int_min, int_max,
+                                                  ext_min, ext_max, spacing );
+  
+  switch(dir) {
+  case 0: {
+    delta = spacing[0];
+    bb[0] = bbox[0]; bb[1] = bbox[1];
+    gsize = nghostzones[0];
+    break;
+  }
+  case 1: {
+    delta = spacing[1];
+    bb[0] = bbox[2]; bb[1] = bbox[3];
+    gsize = nghostzones[1];
+    break;
+  }
+  case 2: {
+    delta = spacing[2];
+    bb[0] = bbox[4]; bb[1] = bbox[5];
+    gsize = nghostzones[2];
+    break;
+  }
+  default:
+      assert(0);
+  }
+
+  var = (CCTK_REAL *)(CCTK_VarDataPtr(cctkGH,0,var_name));
+  dvar = (CCTK_REAL *)(CCTK_VarDataPtr(cctkGH,0,dvar_name));
+
+  switch(order) {
+  case 2: {
+    CCTK_FNAME(deriv_gf_2_1)(var,&ni,&nj,&nk,&dir,bb,&gsize,&delta,dvar);
+    break;
+  }
+  case 4: {
+    CCTK_FNAME(deriv_gf_4_2)(var,&ni,&nj,&nk,&dir,bb,&gsize,&delta,dvar);
+    break;
+  }
+  case 6: {
+    CCTK_FNAME(deriv_gf_6_3)(var,&ni,&nj,&nk,&dir,bb,&gsize,&delta,dvar);
+    break;
+  }
+  default:
+    assert(0);
+  }
+} 
diff --git a/src/make.code.defn b/src/make.code.defn
new file mode 100644
index 0000000..eee5124
--- /dev/null
+++ b/src/make.code.defn
@@ -0,0 +1,8 @@
+# Main make.code.defn file for thorn SummationByParts
+# $Header$
+
+# Source files in this directory
+SRCS =  Derivatives_2_1.F90 Derivatives_4_2.F90 Derivatives_6_3.F90 call_derivs.c
+
+# Subdirectories containing source files
+SUBDIRS =