KrancTensor.m: Provide a new interface to CreateThorn

This new internal interface derives various things automatically that the user was previously required to provide, for example the groups structure.  It also provides centered finite differencing at 2nd and 4th order (this can be increased) for the derivative PD with the order controlled by the new parameter fdOrder.

1 files changed, 33 insertions, 1 deletions

diff --git a/Tools/CodeGen/KrancTensor.m b/Tools/CodeGen/KrancTensor.m
index d0157c9..13c40bf 100644
--- a/Tools/CodeGen/KrancTensor.m
+++ b/Tools/CodeGen/KrancTensor.m
@@ -26,9 +26,12 @@
 
 $KrancTensorPackage = "TensorToolsKranc`";
 
-BeginPackage["KrancTensor`", {"Errors`", "KrancThorn`", "MapLookup`", "KrancGroups`", "Kranc`", $KrancTensorPackage, "ConservationCalculation`", "TensorTools`"}];
+BeginPackage["KrancTensor`", {"Errors`", "KrancThorn`", "MapLookup`", "KrancGroups`",
+                              "Kranc`", $KrancTensorPackage, "ConservationCalculation`",
+                              "TensorTools`", "KrancGroups`", "Differencing`"}];
 
 CreateKrancThornTT::usage = "Construct a Kranc thorn using tensor expressions.";
+CreateKrancThornTT2::usage = "Construct a Kranc thorn using tensor expressions.";
 
 (* FIXME: Move CreateGroupFromTensor here *)
 
@@ -102,5 +105,34 @@ makeGroupExplicit[g_] :=
     newGroup = SetGroupVariables[g, newVariables];
     newGroup];
 
+Options[CreateKrancThornTT2] = ThornOptions;
+
+DefFn[CreateKrancThornTT2[thornName_String, opts:OptionsPattern[]] :=
+  Module[
+    {groups, pderivs, opts2, fdOrder = Global`fdOrder, PDstandard = Global`PDstandard},
+    groups = Map[CreateGroupFromTensor, OptionValue[Variables]];
+
+    pderivs =
+    Join[OptionValue[PartialDerivatives],
+         {
+           PDstandard[i_] ->
+           StandardCenteredDifferenceOperator[1,fdOrder/2,i],
+           PDstandard[i_, i_] ->
+           StandardCenteredDifferenceOperator[2,fdOrder/2,i],
+           PDstandard[i_, j_] ->
+           StandardCenteredDifferenceOperator[1,fdOrder/2,i] StandardCenteredDifferenceOperator[1,fdOrder/2,j]
+         }];
+
+    opts2 = mapReplaceAdd[{opts}, PartialDerivatives, pderivs];
+
+    opts2 = mapReplaceAdd[opts2, IntParameters, Join[lookup[opts2,IntParameters,{}],
+                                                     {{Name -> fdOrder, Default -> 2, AllowedValues -> {2, 4}}}]];
+
+    opts2 = opts2 /. PD -> PDstandard;
+
+    CreateKrancThornTT[groups,OptionValue[ParentDirectory],thornName,
+                       DeclaredGroups -> Map[groupName, groups],
+                       Sequence@@opts2]]];
+
 End[];
 EndPackage[];