Provide a coordinate-thorn and symmetry-thorn independent way of

specifying the shape of the physical domain and the location of the
boundary points.  The advantage of that is that it is now much easier
to change the resolution.


git-svn-id: http://svn.cactuscode.org/arrangements/CactusBase/CoordBase/trunk@7 0337457d-221f-4ee6-a5f0-14255d5370d8

17 files changed, 1719 insertions, 1 deletions

diff --git a/doc/documentation.tex b/doc/documentation.tex
index b289d1b..ab06462 100644
--- a/doc/documentation.tex
+++ b/doc/documentation.tex
@@ -100,6 +100,11 @@
 CoordBase provides a mechanism for registering coordinate systems, and
 maintaining a database of coordinate systems and their coordinates,
 using key-value tables.
+
+CoordBase also provides a way for specifying the extent of the
+simulation domain that is independent of the actual coordinate and
+symmetry thorns, and for specifying the discretisation of the boundary
+that is independent of the actual boundary thorns.
 \end{abstract}
 
 
@@ -402,6 +407,190 @@ Even though another thorn has set a default for all 2D grid variables
 to something else, Coord\_GroupSystem() will always return the handle
 for sphere2d when called on this group.
 
+
+\section{Specifying the extent of the physical domain}
+\label{CactusBase:CoordBase:domain}
+
+CoordBase provides a way for specifying the extent of the simulation
+domain that is independent of the actual coordinate and symmetry
+thorns.  This is necessary because the size of the physical domain is
+not necessarily the same as the size of the computational grid, which
+is usually enlarged by symmetry zones and/or boundary zones.
+
+The physical domain is characterised by the location of its lower and
+upper boundary and by its grid spacing.  These quantities are related
+to the extent and the number of grid cells that span the domain.  The
+relation between the size of the domain and the size of the
+computational grid is defined in section
+{\ref{CactusBase:CoordBase:domain}} below.  The domain extent as
+defined in this section is the continuum extent and is independent of
+the actual discretisation.  This makes it possible to adapt the same
+domain specification for different resolutions by changing only a
+single parameter.
+
+The domain is specified in one of the following ways, which is
+selected by the keyword parameter {\texttt{domainsize}}:
+\begin{description}
+\item[{\texttt{minmax}}:]
+by the location of its lower and upper boundary
+\item[{\texttt{extent}}:]
+by its extent, i.e.\ its width
+\item[{\texttt{spacing}}:]
+by grid spacing and the number of grid cells
+\end{description}
+The domain specification uses the number of grid cells instead of the
+number of grid points because the latter can easily lead to one-off
+errors.
+
+The domain size in each dimension is specificied in equivalent ways.
+For example, the $x$-dimension is specified by a set of some of the
+following parameters:
+\begin{description}
+\item[{\texttt{zero\_origin\_x}} (boolean):]
+When the domain size is specified by extent or by spacing, then the
+origin (lower boundary) can either be located at $x=0$, which leads to
+the domain $x \in [0,L]$ with the extent $L$, or the domain can be
+symmetric with respect to $x=0$, which leads to $x \in [-L/2,L/2]$.
+\item[{\texttt{xmin}} and {\texttt{xmax}}:]
+When the domain is specified by the location of its lower and upper
+boundary, then these specify the locations.
+\item[{\texttt{xextent}}:]
+When the domain is specified by its extent, then this specifies the
+extent.
+\item[{\texttt{dx}} (real) and {\texttt{ncells\_x}} (int):]
+When the domain is specified by grid spacing and the number of grid
+cells, then these specify the grid spacing and the number of grid
+cells.
+\end{description}
+
+
+\section{Specifying the location of the boundary points}
+\label{CactusBase:CoordBase:boundary}
+
+CoordBase also provides a way for specifying the discretisation of the
+boundary that is independent of the actual boundary thorns.  This
+defines the locations of the boundary points and thus the extent of
+the computational grid.
+
+Each face of the grid is specified independently.  The specification
+does not depend on the resolution, so that it need not be adapted when
+the resolution is changed.  Figure
+{\ref{CactusBase:CoordBase:fig-domain}} shows a domain with several
+interior grid points and one boundary point.
+
+\begin{figure}
+\begin{center}
+\includegraphics[scale=0.75]{domain}
+\end{center}
+\caption{A domain (rectangle) with three interior points (empty
+circles) and one boundary point (full circle).}
+\label{CactusBase:CoordBase:fig-domain}
+\end{figure}
+
+While the physical boundary has a width of zero, the computational
+grid can have more than one boundary points.  This {\emph{boundary
+size}} is defined by the integer parameter
+{\texttt{boundary\_size\_x\_lower}} for the lower $x$ boundary (and
+similarly for the other boundaries).  Figure
+{\ref{CactusBase:CoordBase:fig-domain-external}} shows an example
+where there are two boundary points.  When it is necessary to increase
+the number of boundary points (e.g., to accommodate a larger stencil),
+then this is the only parameter that needs to be changed.
+
+\begin{figure}
+\begin{center}
+\includegraphics[scale=0.75]{domain-external}
+\end{center}
+\caption{A domain (rectangle) with three interior points (empty
+circles) and two boundary points (full circles).  This is an exterior
+boundary, i.e.\ the boundary points are located outside of the
+physical domain.}
+\label{CactusBase:CoordBase:fig-domain-external}
+\end{figure}
+
+Depending on the physical setup --- and depending on the personal
+taste --- the boundary points should be located either inside or
+outside of the physical boundary.  The boolean parameter
+{\texttt{boundary\_internal\_x\_lower}} specifies whether the boundary
+points extend inwards at the lower $x$ face.  Figure
+{\ref{CactusBase:CoordBase:fig-domain-internal}} shows the same
+example, but with internal boundary points.
+
+\begin{figure}
+\begin{center}
+\includegraphics[scale=0.75]{domain-internal}
+\end{center}
+\caption{A domain (rectangle) with two interior points (empty circles)
+and two boundary points (full circles).  This is an interior boundary,
+i.e.\ the boundary points are located inside of the physical domain.}
+\label{CactusBase:CoordBase:fig-domain-internal}
+\end{figure}
+
+Depending on the physical setup --- and depending on the personal
+taste --- the boundary points should either be staggered about the
+physical boundary, or the last boundary point should be located
+exactly on the physical boundary.  This is specified by the boolean
+parameter {\texttt{boundary\_staggered\_x\_lower}}.  Figures
+{\ref{CactusBase:CoordBase:fig-domain-external-staggered}} and
+{\ref{CactusBase:CoordBase:fig-domain-internal-staggered}} show
+exampled of external and internal staggered boundary points.
+
+\begin{figure}
+\begin{center}
+\includegraphics[scale=0.75]{domain-external-staggered}
+\end{center}
+\caption{A domain (rectangle) with three interior points (empty circles)
+and two boundary points (full circles) which are staggered about the
+physical boundary.  (This is an exterior boundary.)}
+\label{CactusBase:CoordBase:fig-domain-external-staggered}
+\end{figure}
+
+\begin{figure}
+\begin{center}
+\includegraphics[scale=0.75]{domain-internal-staggered}
+\end{center}
+\caption{A domain (rectangle) with two interior points (empty circles)
+and two boundary points (full circles) which are staggered about the
+physical boundary.  (This is an interior boundary.)}
+\label{CactusBase:CoordBase:fig-domain-internal-staggered}
+\end{figure}
+
+Finally, the integer parameter {\texttt{boundary\_shiftout\_x\_lower}}
+can be used to shift the boundary points outwards (or inwards with
+negative values) by multiples of the grid spacing.  Figure
+{\ref{CactusBase:CoordBase:fig-domain-external-shiftout}} shows an
+example of an exterior, non-staggered boundary with a shiftout of one.
+
+\begin{figure}
+\begin{center}
+\includegraphics[scale=0.75]{domain-external-shiftout}
+\end{center}
+\caption{A domain (rectangle) with four interior points (empty circles)
+and two boundary points (full circles) which are shifted outwards by
+one grid point.  (This is an exterior, non-staggered boundary.)}
+\label{CactusBase:CoordBase:fig-domain-external-shiftout}
+\end{figure}
+
+The following table gives examples for common situations:
+
+\begin{tabular}{l|ccc|l}
+Boundary condition & internal? & staggered? & shiftout & example \\\hline
+reflection symmetry, not staggered & no & no & 1
+   & figure {\ref{CactusBase:CoordBase:fig-domain-external-shiftout}} \\
+reflection symmetry, staggered & no & yes & 0
+   & figure {\ref{CactusBase:CoordBase:fig-domain-external-staggered}} \\
+periodicity, closed boundary & no & no & 1
+   & figure {\ref{CactusBase:CoordBase:fig-domain-external-shiftout}} \\
+periodicity, open boundary & no & no & 0
+   & figure {\ref{CactusBase:CoordBase:fig-domain-external}} \\
+periodicity, staggered boundary & no & yes & 0
+   & figure {\ref{CactusBase:CoordBase:fig-domain-external-staggered}}
+\end{tabular}
+
+For other boundary conditions such as Dirichlet or Robin, one can
+choose these parameters freely.
+
+
 % Do not delete next line
 % END CACTUS THORNGUIDE
 
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diff --git a/doc/domain-external.fig b/doc/domain-external.fig
new file mode 100644
index 0000000..bf40bae
--- /dev/null
+++ b/doc/domain-external.fig
@@ -0,0 +1,16 @@
+#FIG 3.2
+Landscape
+Center
+Metric
+A4      
+100.00
+Single
+-2
+1200 2
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diff --git a/doc/domain-internal-staggered.fig b/doc/domain-internal-staggered.fig
new file mode 100644
index 0000000..a862672
--- /dev/null
+++ b/doc/domain-internal-staggered.fig
@@ -0,0 +1,15 @@
+#FIG 3.2
+Landscape
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+A4      
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+Single
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+2 2 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 5
+	 675 450 2925 450 2925 1800 675 1800 675 450
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new file mode 100644
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diff --git a/doc/domain-internal.fig b/doc/domain-internal.fig
new file mode 100644
index 0000000..475fa9a
--- /dev/null
+++ b/doc/domain-internal.fig
@@ -0,0 +1,15 @@
+#FIG 3.2
+Landscape
+Center
+Metric
+A4      
+100.00
+Single
+-2
+1200 2
+1 3 0 1 0 7 50 -1 -1 0.000 1 0.0000 1800 1125 113 113 1800 1125 1913 1125
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+1 3 0 1 0 0 50 -1 20 0.000 1 0.0000 1350 1125 113 113 1350 1125 1463 1125
+2 2 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 5
+	 900 450 3150 450 3150 1800 900 1800 900 450
diff --git a/doc/domain.eps b/doc/domain.eps
new file mode 100644
index 0000000..3f8b480
--- /dev/null
+++ b/doc/domain.eps
@@ -0,0 +1,127 @@
+%!PS-Adobe-2.0 EPSF-2.0
+%%Title: domain.fig
+%%Creator: fig2dev Version 3.2 Patchlevel 4
+%%CreationDate: Mon Jan 19 23:34:48 2004
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diff --git a/doc/domain.fig b/doc/domain.fig
new file mode 100644
index 0000000..566055a
--- /dev/null
+++ b/doc/domain.fig
@@ -0,0 +1,15 @@
+#FIG 3.2
+Landscape
+Center
+Metric
+A4      
+100.00
+Single
+-2
+1200 2
+1 3 0 1 0 7 50 -1 -1 0.000 1 0.0000 1800 1125 113 113 1800 1125 1913 1125
+1 3 0 1 0 7 50 -1 -1 0.000 1 0.0000 1350 1125 113 113 1350 1125 1463 1125
+1 3 0 1 0 0 50 -1 20 0.000 1 0.0000 450 1125 113 113 450 1125 563 1125
+1 3 0 1 0 7 50 -1 -1 0.000 1 0.0000 900 1125 113 113 900 1125 1013 1125
+2 2 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 5
+	 450 450 2700 450 2700 1800 450 1800 450 450
diff --git a/interface.ccl b/interface.ccl
index 6133c52..6029816 100644
--- a/interface.ccl
+++ b/interface.ccl
@@ -4,3 +4,77 @@
 implements: CoordBase 
 
 include header: CoordBase.h in CoordBase.h
+
+
+
+# The location of the boundary points
+
+CCTK_INT FUNCTION GetBoundarySpecification \
+  (CCTK_INT IN size, \
+   CCTK_INT OUT ARRAY nboundaryzones, \
+   CCTK_INT OUT ARRAY is_internal, \
+   CCTK_INT OUT ARRAY is_staggered, \
+   CCTK_INT OUT ARRAY shiftout)
+PROVIDES FUNCTION GetBoundarySpecification \
+   WITH CoordBase_GetBoundarySpecification \
+   LANGUAGE C
+
+
+
+# The overall extent of the domain
+
+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)
+PROVIDES FUNCTION GetDomainSpecification \
+   WITH CoordBase_GetDomainSpecification \
+   LANGUAGE C
+
+
+
+# Convert between boundaries types
+
+CCTK_INT FUNCTION ConvertFromPhysicalBoundary \
+  (CCTK_INT INT size, \
+   CCTK_REAL IN  ARRAY physical_min, \
+   CCTK_REAL IN  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 IN  ARRAY spacing)
+PROVIDES FUNCTION ConvertFromPhysicalBoundary \
+   WITH CoordBase_ConvertFromPhysicalBoundary \
+   LANGUAGE C
+
+CCTK_INT FUNCTION ConvertFromInteriorBoundary \
+  (CCTK_INT INT size, \
+   CCTK_REAL OUT ARRAY physical_min, \
+   CCTK_REAL OUT ARRAY physical_max, \
+   CCTK_REAL IN  ARRAY interior_min, \
+   CCTK_REAL IN  ARRAY interior_max, \
+   CCTK_REAL OUT ARRAY exterior_min, \
+   CCTK_REAL OUT ARRAY exterior_max, \
+   CCTK_REAL IN  ARRAY spacing)
+PROVIDES FUNCTION ConvertFromInteriorBoundary \
+   WITH CoordBase_ConvertFromInteriorBoundary \
+   LANGUAGE C
+
+CCTK_INT FUNCTION ConvertFromExteriorBoundary \
+  (CCTK_INT INT 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 IN  ARRAY exterior_min, \
+   CCTK_REAL IN  ARRAY exterior_max, \
+   CCTK_REAL IN  ARRAY spacing)
+PROVIDES FUNCTION ConvertFromExteriorBoundary \
+   WITH CoordBase_ConvertFromExteriorBoundary \
+   LANGUAGE C
diff --git a/param.ccl b/param.ccl
index c294bac..213304a 100644
--- a/param.ccl
+++ b/param.ccl
@@ -1,2 +1,251 @@
 # Parameter definitions for thorn CoordBase
 # $Header$
+
+
+
+###############################################################################
+###   Domain specification                                                  ###
+###############################################################################
+
+KEYWORD domainsize "Domain size specification"
+{
+  "minmax"      :: "lower and upper boundary locations"
+  "extent"      :: "coordinate extent"
+  "spacing"     :: "grid spacing and number of grid cells"
+} "minmax"
+
+KEYWORD spacing "Grid spacing specification"
+{
+  "gridspacing" :: "grid spacing"
+  "numcells"    :: "number of grid cells"
+} "gridspacing"
+
+
+
+# Domain description in the x direction.
+# The other domain descriptions are equivalent.
+
+BOOLEAN zero_origin_x "Is the lower boundary located at x=0?"
+{
+} "no"
+
+CCTK_REAL xmin "Location of lower x boundary"
+{
+  (*:*) :: ""
+} 0.0
+
+CCTK_REAL xmax "Location of upper x boundary"
+{
+  (*:*) :: ""
+} 1.0
+
+CCTK_REAL xextent "Domain extent in x direction"
+{
+  (0:*) :: ""
+} 1.0
+
+CCTK_REAL dx "Grid spacing in x direction"
+{
+  (0:*) :: ""
+} 1.0
+
+CCTK_INT ncells_x "Number of grid cells in x direction"
+{
+  1:* :: ""
+} 1
+
+# Domain description in the y direction.
+# The other domain descriptions are equivalent.
+
+BOOLEAN zero_origin_y "Is the lower boundary located at y=0?"
+{
+} "no"
+
+CCTK_REAL ymin "Location of lower y boundary"
+{
+  (*:*) :: ""
+} 0.0
+
+CCTK_REAL ymax "Location of upper y boundary"
+{
+  (*:*) :: ""
+} 1.0
+
+CCTK_REAL yextent "Domain extent in y direction"
+{
+  (0:*) :: ""
+} 1.0
+
+CCTK_REAL dy "Grid spacing in y direction"
+{
+  (0:*) :: ""
+} 1.0
+
+CCTK_INT ncells_y "Number of grid cells in y direction"
+{
+  1:* :: ""
+} 1
+
+# Domain description in the z direction.
+# The other domain descriptions are equivalent.
+
+BOOLEAN zero_origin_z "Is the lower boundary located at z=0?"
+{
+} "no"
+
+CCTK_REAL zmin "Location of lower z boundary"
+{
+  (*:*) :: ""
+} 0.0
+
+CCTK_REAL zmax "Location of upper z boundary"
+{
+  (*:*) :: ""
+} 1.0
+
+CCTK_REAL zextent "Domain extent in z direction"
+{
+  (0:*) :: ""
+} 1.0
+
+CCTK_REAL dz "Grid spacing in z direction"
+{
+  (0:*) :: ""
+} 1.0
+
+CCTK_INT ncells_z "Number of grid cells in z direction"
+{
+  1:* :: ""
+} 1
+
+
+
+###############################################################################
+###   Boundary specification                                                ###
+###############################################################################
+
+# Boundary description for the lower x face.
+# The other boundary descriptions are equivalent.
+
+CCTK_INT boundary_size_x_lower "Boundary zones at the lower x face"
+{
+  0:* :: ""
+} 1
+
+BOOLEAN boundary_internal_x_lower "Do the boundary points extend inwards at the lower x face?"
+{
+} "no"
+
+BOOLEAN boundary_staggered_x_lower "Is the boundary is staggered about the grid points at the lower x face?"
+{
+} "no"
+
+CCTK_INT boundary_shiftout_x_lower "Offset between the boundary location and the first boundary point at the lower x face"
+{
+  *:* :: "when not staggered: use 0 for an open, 1 for a closed open manifold"
+} 0
+
+# Boundary description for the upper x face.
+# The other boundary descriptions are equivalent.
+
+CCTK_INT boundary_size_x_upper "Boundary zones at the upper x face"
+{
+  0:* :: ""
+} 1
+
+BOOLEAN boundary_internal_x_upper "Do the boundary points extend inwards at the upper x face?"
+{
+} "no"
+
+BOOLEAN boundary_staggered_x_upper "Is the boundary is staggered about the grid points at the upper x face?"
+{
+} "no"
+
+CCTK_INT boundary_shiftout_x_upper "Offset between the boundary location and the first boundary point at the upper x face"
+{
+  *:* :: "when not staggered: use 0 for an open, 1 for a closed open manifold"
+} 0
+
+# Boundary description for the lower y face.
+# The other boundary descriptions are equivalent.
+
+CCTK_INT boundary_size_y_lower "Boundary zones at the lower y face"
+{
+  0:* :: ""
+} 1
+
+BOOLEAN boundary_internal_y_lower "Do the boundary points extend inwards at the lower y face?"
+{
+} "no"
+
+BOOLEAN boundary_staggered_y_lower "Is the boundary is staggered about the grid points at the lower y face?"
+{
+} "no"
+
+CCTK_INT boundary_shiftout_y_lower "Offset between the boundary location and the first boundary point at the lower y face"
+{
+  *:* :: "when not staggered: use 0 for an open, 1 for a closed open manifold"
+} 0
+
+# Boundary description for the upper y face.
+# The other boundary descriptions are equivalent.
+
+CCTK_INT boundary_size_y_upper "Boundary zones at the upper y face"
+{
+  0:* :: ""
+} 1
+
+BOOLEAN boundary_internal_y_upper "Do the boundary points extend inwards at the upper y face?"
+{
+} "no"
+
+BOOLEAN boundary_staggered_y_upper "Is the boundary is staggered about the grid points at the upper y face?"
+{
+} "no"
+
+CCTK_INT boundary_shiftout_y_upper "Offset between the boundary location and the first boundary point at the upper y face"
+{
+  *:* :: "when not staggered: use 0 for an open, 1 for a closed open manifold"
+} 0
+
+# Boundary description for the lower z face.
+# The other boundary descriptions are equivalent.
+
+CCTK_INT boundary_size_z_lower "Boundary zones at the lower z face"
+{
+  0:* :: ""
+} 1
+
+BOOLEAN boundary_internal_z_lower "Do the boundary points extend inwards at the lower z face?"
+{
+} "no"
+
+BOOLEAN boundary_staggered_z_lower "Is the boundary is staggered about the grid points at the lower z face?"
+{
+} "no"
+
+CCTK_INT boundary_shiftout_z_lower "Offset between the boundary location and the first boundary point at the lower z face"
+{
+  *:* :: "when not staggered: use 0 for an open, 1 for a closed open manifold"
+} 0
+
+# Boundary description for the upper z face.
+# The other boundary descriptions are equivalent.
+
+CCTK_INT boundary_size_z_upper "Boundary zones at the upper z face"
+{
+  0:* :: ""
+} 1
+
+BOOLEAN boundary_internal_z_upper "Do the boundary points extend inwards at the upper z face?"
+{
+} "no"
+
+BOOLEAN boundary_staggered_z_upper "Is the boundary is staggered about the grid points at the upper z face?"
+{
+} "no"
+
+CCTK_INT boundary_shiftout_z_upper "Offset between the boundary location and the first boundary point at the upper z face"
+{
+  *:* :: "when not staggered: use 0 for an open, 1 for a closed open manifold"
+} 0
diff --git a/src/Domain.c b/src/Domain.c
new file mode 100644
index 0000000..ab917a9
--- /dev/null
+++ b/src/Domain.c
@@ -0,0 +1,338 @@
+/* $Header$ */
+
+#include <assert.h>
+
+#include "cctk.h"
+#include "cctk_Parameters.h"
+
+
+
+CCTK_INT CoordBase_GetBoundarySpecification
+  (CCTK_INT const size,
+   CCTK_INT * const nboundaryzones,
+   CCTK_INT * const is_internal,
+   CCTK_INT * const is_staggered,
+   CCTK_INT * const shiftout)
+{
+  DECLARE_CCTK_PARAMETERS;
+  
+  assert (size>=0);
+  assert (nboundaryzones);
+  assert (is_internal);
+  assert (is_staggered);
+  assert (shiftout);
+  
+  assert (size == 6);
+  
+  nboundaryzones[0] = boundary_size_x_lower;
+  nboundaryzones[1] = boundary_size_x_upper;
+  nboundaryzones[2] = boundary_size_y_lower;
+  nboundaryzones[3] = boundary_size_y_upper;
+  nboundaryzones[4] = boundary_size_z_lower;
+  nboundaryzones[5] = boundary_size_z_upper;
+  
+  is_internal[0] = boundary_internal_x_lower;
+  is_internal[1] = boundary_internal_x_upper;
+  is_internal[2] = boundary_internal_y_lower;
+  is_internal[3] = boundary_internal_y_upper;
+  is_internal[4] = boundary_internal_z_lower;
+  is_internal[5] = boundary_internal_z_upper;
+  
+  is_staggered[0] = boundary_staggered_x_lower;
+  is_staggered[1] = boundary_staggered_x_upper;
+  is_staggered[2] = boundary_staggered_y_lower;
+  is_staggered[3] = boundary_staggered_y_upper;
+  is_staggered[4] = boundary_staggered_z_lower;
+  is_staggered[5] = boundary_staggered_z_upper;
+  
+  shiftout[0] = boundary_shiftout_x_lower;
+  shiftout[1] = boundary_shiftout_x_upper;
+  shiftout[2] = boundary_shiftout_y_lower;
+  shiftout[3] = boundary_shiftout_y_upper;
+  shiftout[4] = boundary_shiftout_z_lower;
+  shiftout[5] = boundary_shiftout_z_upper;
+  
+  return 0;
+}
+
+
+
+CCTK_INT CoordBase_GetDomainSpecification
+  (CCTK_INT const size,
+   CCTK_REAL * const physical_min,
+   CCTK_REAL * const physical_max,
+   CCTK_REAL * const interior_min,
+   CCTK_REAL * const interior_max,
+   CCTK_REAL * const exterior_min,
+   CCTK_REAL * const exterior_max,
+   CCTK_REAL * const thespacing)
+{
+  DECLARE_CCTK_PARAMETERS;
+  
+  int d;
+  int ierr;
+  
+  assert (size>=0);
+  assert (physical_min);
+  assert (physical_max);
+  assert (interior_min);
+  assert (interior_max);
+  assert (exterior_min);
+  assert (exterior_max);
+  assert (thespacing);
+  
+  assert (size == 3);
+  
+  
+  
+  if (CCTK_EQUALS (domainsize, "minmax")) {
+    
+    physical_min[0] = xmin;
+    physical_min[1] = ymin;
+    physical_min[2] = zmin;
+    physical_max[0] = xmax;
+    physical_max[1] = ymax;
+    physical_max[2] = zmax;
+    if (CCTK_EQUALS (spacing, "gridspacing")) {
+      thespacing[0] = dx;
+      thespacing[1] = dy;
+      thespacing[2] = dz;
+    } else if (CCTK_EQUALS (spacing, "numcells")) {
+      thespacing[0] = (physical_max[0] - physical_min[0]) / ncells_x;
+      thespacing[1] = (physical_max[1] - physical_min[1]) / ncells_y;
+      thespacing[2] = (physical_max[2] - physical_min[2]) / ncells_z;
+    }
+    
+  } else if (CCTK_EQUALS (domainsize, "extent")) {
+    
+    if (zero_origin_x) {
+      physical_min[0] = xmin;
+      physical_max[0] = xmin + xextent;
+    } else {
+      physical_min[0] = - xextent / 2;
+      physical_max[0] = + xextent / 2;
+    }
+    if (zero_origin_y) {
+      physical_min[1] = ymin;
+      physical_max[1] = ymin + yextent;
+    } else {
+      physical_min[1] = - yextent / 2;
+      physical_max[1] = + yextent / 2;
+    }
+    if (zero_origin_z) {
+      physical_min[2] = zmin;
+      physical_max[2] = zmin + zextent;
+    } else {
+      physical_min[2] = - zextent / 2;
+      physical_max[2] = + zextent / 2;
+    }
+    if (CCTK_EQUALS (spacing, "gridspacing")) {
+      thespacing[0] = dx;
+      thespacing[1] = dy;
+      thespacing[2] = dz;
+    } else if (CCTK_EQUALS (spacing, "numcells")) {
+      thespacing[0] = (physical_max[0] - physical_min[0]) / ncells_x;
+      thespacing[1] = (physical_max[1] - physical_min[1]) / ncells_y;
+      thespacing[2] = (physical_max[2] - physical_min[2]) / ncells_z;
+    }
+    
+  } else if (CCTK_EQUALS (domainsize, "spacing")) {
+    
+    if (zero_origin_x) {
+      physical_min[0] = xmin;
+      physical_max[0] = xmin + dx * ncells_x;
+    } else {
+      physical_min[0] = - dx * ncells_x / 2;
+      physical_max[0] = + dx * ncells_x / 2;
+    }
+    if (zero_origin_y) {
+      physical_min[1] = ymin;
+      physical_max[1] = ymin + dy * ncells_y;
+    } else {
+      physical_min[1] = - dy * ncells_y / 2;
+      physical_max[1] = + dy * ncells_y / 2;
+    }
+    if (zero_origin_z) {
+      physical_min[2] = - dz * ncells_z / 2;
+      physical_max[2] = + dz * ncells_z / 2;
+    } else {
+      physical_min[2] = zmin;
+      physical_max[2] = zmin + dz * ncells_z;
+    }
+    thespacing[0] = dx;
+    thespacing[1] = dy;
+    thespacing[2] = dz;
+    
+  } else {
+    assert (0);
+  }
+  
+  ierr = ConvertFromPhysicalBoundary
+    (size, physical_min, physical_max, interior_min, interior_max,
+     exterior_min, exterior_max, thespacing);
+  assert (!ierr);
+  
+  return 0;
+}
+
+
+
+CCTK_INT CoordBase_ConvertFromPhysicalBoundary
+  (CCTK_INT const size,
+   CCTK_REAL const * const physical_min,
+   CCTK_REAL const * const physical_max,
+   CCTK_REAL * const interior_min,
+   CCTK_REAL * const interior_max,
+   CCTK_REAL * const exterior_min,
+   CCTK_REAL * const exterior_max,
+   CCTK_REAL const * const thespacing)
+{
+  CCTK_INT nboundaryzones[6];
+  CCTK_INT is_internal[6];
+  CCTK_INT is_staggered[6];
+  CCTK_INT shiftout[6];
+  
+  int d;
+  int ierr;
+  
+  assert (size>=0);
+  assert (physical_min);
+  assert (physical_max);
+  assert (interior_min);
+  assert (interior_max);
+  assert (exterior_min);
+  assert (exterior_max);
+  assert (thespacing);
+  
+  assert (size == 3);
+  
+  ierr = CoordBase_GetBoundarySpecification
+    (6, nboundaryzones, is_internal, is_staggered, shiftout);
+  assert (!ierr);
+  
+  for (d=0; d<3; ++d) {
+    
+    exterior_min[d] = physical_min[d] - thespacing[d] *
+      (+ (is_internal[2*d] ? 0 : nboundaryzones[2*d] - 1)
+       + (is_staggered[2*d] ? 0.5 : 0.0)
+       + shiftout[2*d]);
+    exterior_max[d] = physical_max[d] + thespacing[d] *
+      (+ (is_internal[2*d+1] ? 0 : nboundaryzones[2*d+1] - 1)
+       + (is_staggered[2*d+1] ? 0.5 : 0.0)
+       + shiftout[2*d+1]);
+  
+    interior_min[d] = exterior_min[d] + thespacing[d] * nboundaryzones[2*d];
+    interior_max[d] = exterior_max[d] - thespacing[d] * nboundaryzones[2*d+1];
+
+  }
+  
+  return 0;
+}
+
+
+
+CCTK_INT CoordBase_ConvertFromInteriorBoundary
+  (CCTK_INT const size,
+   CCTK_REAL * const physical_min,
+   CCTK_REAL * const physical_max,
+   CCTK_REAL const * const interior_min,
+   CCTK_REAL const * const interior_max,
+   CCTK_REAL * const exterior_min,
+   CCTK_REAL * const exterior_max,
+   CCTK_REAL const * const thespacing)
+{
+  CCTK_INT nboundaryzones[6];
+  CCTK_INT is_internal[6];
+  CCTK_INT is_staggered[6];
+  CCTK_INT shiftout[6];
+  
+  int d;
+  int ierr;
+  
+  assert (size>=0);
+  assert (physical_min);
+  assert (physical_max);
+  assert (interior_min);
+  assert (interior_max);
+  assert (exterior_min);
+  assert (exterior_max);
+  assert (thespacing);
+  
+  assert (size == 3);
+  
+  ierr = CoordBase_GetBoundarySpecification
+    (6, nboundaryzones, is_internal, is_staggered, shiftout);
+  assert (!ierr);
+  
+  for (d=0; d<3; ++d) {
+    
+    exterior_min[d] = interior_min[d] - thespacing[d] * nboundaryzones[2*d];
+    exterior_max[d] = interior_max[d] + thespacing[d] * nboundaryzones[2*d+1];
+
+    physical_min[d] = exterior_min[d] + thespacing[d] *
+      (+ (is_internal[2*d] ? 0 : nboundaryzones[2*d] - 1)
+       + (is_staggered[2*d] ? 0.5 : 0.0)
+       + shiftout[2*d]);
+    physical_max[d] = exterior_max[d] - thespacing[d] *
+      (+ (is_internal[2*d+1] ? 0 : nboundaryzones[2*d+1] - 1)
+       + (is_staggered[2*d+1] ? 0.5 : 0.0)
+       + shiftout[2*d+1]);
+  
+  }
+  
+  return 0;
+}
+
+
+
+CCTK_INT CoordBase_ConvertFromExteriorBoundary
+  (CCTK_INT const size,
+   CCTK_REAL * const physical_min,
+   CCTK_REAL * const physical_max,
+   CCTK_REAL * const interior_min,
+   CCTK_REAL * const interior_max,
+   CCTK_REAL const * const exterior_min,
+   CCTK_REAL const * const exterior_max,
+   CCTK_REAL const * const thespacing)
+{
+  CCTK_INT nboundaryzones[6];
+  CCTK_INT is_internal[6];
+  CCTK_INT is_staggered[6];
+  CCTK_INT shiftout[6];
+  
+  int d;
+  int ierr;
+  
+  assert (size>=0);
+  assert (physical_min);
+  assert (physical_max);
+  assert (interior_min);
+  assert (interior_max);
+  assert (exterior_min);
+  assert (exterior_max);
+  assert (thespacing);
+  
+  assert (size == 3);
+  
+  ierr = CoordBase_GetBoundarySpecification
+    (6, nboundaryzones, is_internal, is_staggered, shiftout);
+  assert (!ierr);
+  
+  for (d=0; d<3; ++d) {
+    
+    physical_min[d] = exterior_min[d] + thespacing[d] *
+      (+ (is_internal[2*d] ? 0 : nboundaryzones[2*d] - 1)
+       + (is_staggered[2*d] ? 0.5 : 0.0)
+       + shiftout[2*d]);
+    physical_max[d] = exterior_max[d] - thespacing[d] *
+      (+ (is_internal[2*d+1] ? 0 : nboundaryzones[2*d+1] - 1)
+       + (is_staggered[2*d+1] ? 0.5 : 0.0)
+       + shiftout[2*d+1]);
+  
+    interior_min[d] = exterior_min[d] + thespacing[d] * nboundaryzones[2*d];
+    interior_max[d] = exterior_max[d] - thespacing[d] * nboundaryzones[2*d+1];
+
+  }
+  
+  return 0;
+}
diff --git a/src/make.code.defn b/src/make.code.defn
index 0f94373..ec0a0ee 100644
--- a/src/make.code.defn
+++ b/src/make.code.defn
@@ -2,7 +2,7 @@
 # $Header$
 
 # Source files in this directory
-SRCS = CoordBase.c GHExtension.c
+SRCS = Domain.c CoordBase.c GHExtension.c
 
 # Subdirectories containing source files
 SUBDIRS =