Changeset 850 for trunk/source/persistency

Timestamp:

Sep 10, 2008, 5:40:37 PM (17 years ago)

Author:

garnier

Message:

geant4.8.2 beta

Location:

trunk/source/persistency/gdml

Files:

• GNUmakefile (modified) (3 diffs)
• History (modified) (2 diffs)
• include/G4GDMLEvaluator.hh (modified) (2 diffs)
• include/G4GDMLParser.hh (modified) (2 diffs)
• src/G4GDMLEvaluator.cc (modified) (3 diffs)

trunk/source/persistency/gdml/GNUmakefile

@@ -1 @@
-# $Id: GNUmakefile,v 1.6 2007/12/11 15:00:49 gcosmo Exp $
+# $Id: GNUmakefile,v 1.10 2008/07/02 14:15:16 gcosmo Exp $
 # -----------------------------------------------------------------------
 # GNUmakefile for persistency library.  Gabriele Cosmo, 16/11/96.
@@ -14 +14 @@
 CPPFLAGS += -I$(G4INSTALL)/source/global/management/include \
             -I$(G4INSTALL)/source/global/HEPGeometry/include \
+            -I$(G4INSTALL)/source/global/HEPNumerics/include \
             -I$(G4INSTALL)/source/digits_hits/hits/include \
             -I$(G4INSTALL)/source/digits_hits/digits/include \
@@ -24 +25 @@
             -I$(G4INSTALL)/source/geometry/management/include \
             -I$(G4INSTALL)/source/geometry/volumes/include \
-            -I$(G4INSTALL)/source/geometry/management/include \
+            -I$(G4INSTALL)/source/geometry/navigation/include \
             -I$(G4INSTALL)/source/geometry/solids/CSG/include \
             -I$(G4INSTALL)/source/geometry/solids/Boolean/include \

trunk/source/persistency/gdml/History

@@ -1 @@
-$Id: History,v 1.5.2.1 2008/01/16 09:47:42 ztorzsok Exp $
+$Id: History,v 1.89 2008/08/22 16:01:02 gcosmo Exp $
 -------------------------------------------------------------------
 
@@ -18 +18 @@
      ----------------------------------------------------------
 
-16 January, 08  Z.Torzsok (gdml-V09-01-00)
-- Fixed vertex referencing for tessellated-solid in G4GDMLSolids.
-- Fixed entity resolution in G4GDMLBase.
-- Fixed naming of convention for external files in G4GDMLStructure.
+22 August 2008 Tatiana Nikitina (gdml-V09-01-14)
+- G4GDMLReadStructure: added methods ReplicaRead(), AxisRead(), QuantityRead()
+  and introduced corrections in order to read replica volumes conforming to the
+  GDML Schema. Added possibility to read/write replication for Rho and Phi axes.
+- G4GDMLWriteStructure: introduced corrections in order to write replica
+  volumes conforming to the GDML Schema.
+
+20 August 2008 Gabriele Cosmo (gdml-V09-01-13)
+- G4GDMLParser: added argument to Write() for specify if appending or not
+  reference pointer to generated names. Default is TRUE.
+- G4GDMLRead: implemented filtering of names to remove from entity names
+  appended reference pointer which may have been generated. Simplified
+  name generated for physical-volumes to only append "_PV" to its logical
+  volume name.
+- Removed wherever applicable additional strings appended to names.
+
+18 August 2008 Gabriele Cosmo (gdml-V09-01-12)
+- G4GDMLWriteSolids: fixes in naming convention for solids; added specification
+  of units where missing. Introduced parsing of vertices for tessellated solids
+  to avoid duplication in writing.
+
+29 July 2008 Tatiana Nikitina
+- Fixes to parameterisation read and write to match the schema.
+
+24 July 2008 Tatiana Nikitina
+- Added to reader the possibility to have a reference to position and rotation
+  for Boolean solids, as it was possible in GDML_2_10_0.
+
+24 July 2008 Tatiana Nikitina
+- Fixes in reading/writing G4TwistedTrap shapes.
+ 
+22 July 2008 Tatiana Nikitina
+- Added G4Paraboloid to list of supported solids for reader and writer.
+
+16 July 2008 Gabriele Cosmo (gdml-V09-01-11)
+- Renamed internal methods wherever needed to match code policy and having
+  them starting with capital letter.
+
+15 July 2008 Gabriele Cosmo (gdml-V09-01-10)
+- Code review, formatting and adoption of canonical form for calls to
+  G4Exception. Usage of std:: namespace for calls to standard mathematical
+  functions.
+- Added class G4STRead, copy of the original class implemented by Z.Torzsok.
+- Corrected compilation error on Windows/VC++8 compiler for incorrect
+  signature of method in base class.
+
+3 July 2008 Gabriele Cosmo (gdml-V09-01-09)
+- Corrected bugs introduced in last commits for modularization of files;
+  Restored original use of maps.
+- Corrected syntax for parser writer to (optionally) take a pointer to the
+  top physical-volume instead of the logical volume.
+
+25 June 2008 Zoltan Torzsok (gdml-V09-01-08)
+- Units are set according to CLHEP units in G4GDMLEvaluator.
+
+23 June 2008 Zoltan Torzsok
+- Optimised string handling. Schema location can be set in the writer.
+
+20 June 2008 Zoltan Torzsok (gdml-V09-01-07)
+- Set correct URL for schema for 'noNamespaceSchemaLocation' parameter.
+
+17 June 2008 Zoltan Torzsok
+- Added schema validation.
+- Added schema definition files.
+
+10 June 2008 Zoltan Torzsok (gdml-V09-01-06)
+- Modularization can be done either by physvol/depth/mixed.
+  Volume auxiliary information is requested by pointer instead of by name.
+
+9 June 2008 Zoltan Torzsok
+- Naming convention can be configured in the writer.
+
+5 June 2008 Zoltan Torzsok
+- Module name is optional now. If no name is specified,
+  the logical volume name will be the filename.
+
+2 June 2008 Zoltan Torzsok (gdml-V09-01-05)
+- Writer checks if the file to be created does already exist.
+- Added GetVolume() function.
+
+29 May 2008 Zoltan Torzsok
+- Added support for writing modular files.
+
+28 May 2008 Zoltan Torzsok
+- Only the referenced materials/elements/isotopes are written out, not the
+  whole material/element/isotope store.
+- Assigned the name to world physical volume.
+
+27 May 2008 Zoltan Torzsok
+- Optimized/simplified writing of structure: no array required for sorting.
+- Only the referenced solids are written out, not the whole solid store.
+
+23 May 2008 Zoltan Torzsok
+- Writer: precision is now considered in case of scale, rotation and position
+  of the physical-volume. DBL_EPSILON is used to filter precision for avoiding
+  unnecessary scaling, rotation or positioning.
+
+6 May 2008 Zoltan Torzsok (gdml-V09-01-04)
+- Added a constant limiting the maximum number of reflections/displacements of a single solid
+
+21 April 2008 Zoltan Torzsok
+- Divisionvol, replicavol and paramvol are resolved now.
+
+11 April 2008 Zoltan Torzsok (gdml-V09-01-03)
+- Referenced solid in volume is resolved in case of displacements/reflections.
+
+10 April 2008 Zoltan Torzsok
+- Added text output to console to inform of progress during processing.
+
+9 April 2008 Zoltan Torzsok
+- Worked out an algorithm for sorting logical volumes in the writer.
+
+4 April 2008 Zoltan Torzsok
+- Modified writing out of volumes to happen in recursive way.
+  Still needs optimization. Does not recompute touched branches!
+
+1 April 2008 Z.Torzsok
+- Corrected function names to have all starting with capital letter.
+
+11 March 2008 Z.Torzsok (gdml-V09-01-02)
+- Added border surface to reader.
+- Added skin surface to reader.
+- Fixed compilation problems on Intel/icc compiler.
+
+7 March 2008 Z.Torzsok (gdml-V09-01-01)
+- Material properties added to reader
+
+20 February 2008 Z.Torzsok
+- Completed support for parameterised volumes in writer.
+- Name is added to physvol in reader.
+
+19 February 2008 Z.Torzsok
+- Replicavol is simplified and no longer restricted to replication along axes.
+
+18 February 2008 Z.Torzsok
+- Added G4GDMLWriteParamvol class implementing the parameterised volumes
+  in the writer. Added box parameterisation and succesfully tested.
+
+15 February 2008 Z.Torzsok
+- Division volumes added to writer and succesfully tested.
+
+14 February 2008 Z.Torzsok
+- Replica volumes added to writer and succesfully tested.
+
+13 February 2008 Z.Torzsok
+- Added getRotationMatrix() function to G4GDMLReadDefine: this function
+  converts rotation angles into a rotation matrix. This wad used in physvol,
+  reflectedSolid and boolean solid. Now this conversion is in one place
+- Added 'firstrotation' and 'firstposition' to boolean solid. Now the first
+  solid can be transformed too (Boolean solid is succesfully tested).
+
+11 February 2008 Z.Torzsok
+- Added matrices to writer.
+- Exception handling is added to loops (identify infinite loops).
+
+8 Febryary 2008 Z.Torzsok
+- Naming of physvol changed to 'ReferencedVolumeName_in_MotherVolumeName'.
+
+7 February 2008 Z.Torzsok
+- Added twistedtrap and twistedtubs to writer.
+
+6 february 2008 Z.Torzsok
+- Tet, Twistedbox and Twistedtrd added to writer and succesfully tested.
+
+5 February 2008 Z.Torzsok
+- Hype, orb and para added to writer.
+  Succesfully tested, except the para.
+
+1 February 2008 Z.Torzsok
+- Ellipsoid and elliptical-tube added to writer.
+
+31 January 2008 Z.Torzsok
+- Quantities now can be referenced
+- Naming of physical volumes changed: MotherLogicalName_daughter(index)
+
+30 January 2008 Z.Torzsok
+- If there is only one setup defined, name does not matter, that setup
+  will be loaded.
+- Temperature, pressure and state are now processed in the reader.
+  Added Nist support.
+
+28 January 2008 Z.Torzsok
+- Element added to writer.
+- Polyhedra and torus added to writer.
+- Now the package is able to read/write the CMS geometry.
+
+25 January 2008 Z.Torzsok
+- Bugs fixed in the writer in G4GMLWriteStructure::physvolWrite():
+  the signs of the rotational angles were incorrect in certain cases
+  (180 degrees, 90 degrees,...). The reflection was incorrect in case
+  of reflecting a subtree.
+- Now the package is capable of reading and writing back the LHCb
+  geometry correctly.
+
+23 January 2008 Z.Torzsok
+- Composite materials added to writer.
+- Cone and tube added to writer.
+- Boolean solid (intersection, subtraction, union) added to writer.
+
+22 January 2008 Z.Torzsok
+- Extruded solid is added to writer.
+- Reflected solid is removed from the written GDML files.
+  Scale transformation is used instead.
+- Optimization to tha case of reading multiple GDML files and writing out
+  into a single GDML file:
+  The mother volume is moved to the end of the list after its daugthers are
+  processed... only when necessary, when new logical volumes come from the
+  daughters!
+
+21 January 2008 Z.Torzsok
+- Reflected solid is added to the writer.
+- Solved problem of reading multiple GDML files and writing out into a single
+  GDML file:
+  if a logical volume (let's say the mother volume) is instantiated, it will
+  be added to the end of list of volumes (G4LogicalVolumeStore).
+  Once this logical volume is instantiated we can add daughters.
+  If a daughter refers to an external file, additional logical volumes will
+  come. These logical volumes will be added to the list as well, AFTER the
+  mother volume. In the mother volume these logical volumes can be referenced
+  ...but these logical volumes are not instantiated yet when we instantiate
+  the mother! That's why we move the mother volume at the end of the list
+  after the daughters are processed.
+  
+18 January 2008 Z.Torzsok
+- The class hierarchy of the GDML parser/writer is finished:
+  Write <- WriteDefine <- WriteMaterials <- WriteSolids
+        <- WriteSetup <- WriteStructure
+  Parser Read <- ReadDefine <- ReadMaterials <- ReadSolids
+              <- ReadSetup <- ReadParamvol <- ReadStructure.
+
+16 January 2008 Z.Torzsok
+- Starting the materials section.
+
+15 January 2008 Z.Torzsok
+- Writer implements the setup section too.
+
+11 January 2008 Z.Torzsok (gdml-V09-01-00)
+- Reader is now capable of resolving entities.
+
+08 January 2008 Z.Torzsok
+- Vertex referencing is fixed in tessellated solid 
+  (using the identifier "vertex" according to the schema).
+
+07 January 2008 Z.Torzsok
+- Starting to implement the writer.
 
 30 November, 07  Z.Torzsok (gdml-V09-00-04)

trunk/source/persistency/gdml/include/G4GDMLEvaluator.hh

@@ -25 +25 @@
 //
 //
-// $Id: G4GDMLEvaluator.hh,v 1.10 2007/11/28 10:27:18 ztorzsok Exp $
-// GEANT4 tag $Name: geant4-09-01-patch-02 $
+// $Id: G4GDMLEvaluator.hh,v 1.16 2008/07/16 15:46:33 gcosmo Exp $
+// GEANT4 tag $Name: HEAD $
 //
 //
@@ -43 +43 @@
 
 #include <CLHEP/Evaluator/Evaluator.h>
+#include <vector>
 
-#include "G4Types.hh"
-#include "G4String.hh"
-#include "G4Box.hh"
+#include "globals.hh"
 
-class G4GDMLEvaluator {
+class G4GDMLEvaluator
+{
+
+ public:
+
+   G4GDMLEvaluator();
+
+   void DefineConstant(const G4String&, G4double);
+   void DefineVariable(const G4String&, G4double);
+   void DefineMatrix(const G4String&, G4int, std::vector<G4double>);
+   void SetVariable(const G4String&, G4double);
+   G4bool IsVariable(const G4String&) const;
+   G4String SolveBrackets(const G4String&);
+   G4double Evaluate(const G4String&);
+   G4int EvaluateInteger(const G4String&);
+   G4double GetConstant(const G4String&);
+   G4double GetVariable(const G4String&);
+
+ private:
+
    HepTool::Evaluator eval;
    std::vector<G4String> variableList;
-public:
-   G4GDMLEvaluator();
-
-   void defineConstant(const G4String&,G4double);
-   void defineVariable(const G4String&,G4double);
-   void setVariable(const G4String&,G4double);
-   void checkVariable(const G4String&);
-
-   G4double Evaluate(const G4String&);
-   G4int EvaluateInteger(const G4String&);
 };
 

trunk/source/persistency/gdml/include/G4GDMLParser.hh

@@ -25 +25 @@
 //
 //
-// $Id: G4GDMLParser.hh,v 1.10 2007/11/30 11:58:46 ztorzsok Exp $
-// GEANT4 tag $Name: geant4-09-01-patch-02 $
+// $Id: G4GDMLParser.hh,v 1.53 2008/08/21 12:17:09 gcosmo Exp $
+// GEANT4 tag $Name: HEAD $
 //
 //
@@ -33 +33 @@
 // Class description:
 //
+// GDML main parser.
+
 // History:
 // - Created.                                  Zoltan Torzsok, November 2007
 // -------------------------------------------------------------------------
-
+ 
 #ifndef _G4GDMLPARSER_INCLUDED_
 #define _G4GDMLPARSER_INCLUDED_
 
-#include "G4GDMLStructure.hh"
+#include "G4GDMLReadStructure.hh"
+#include "G4GDMLWriteStructure.hh"
+#include "G4STRead.hh"
 
-class G4GDMLParser {
-   G4GDMLStructure structure;
-public:
-   void Read(const G4String& fileName) { structure.Parse(fileName); }
-   G4VPhysicalVolume* GetWorldVolume(const G4String& setupName="Default") { return structure.getTopVolume(setupName); }
+#define G4GDML_DEFAULT_SCHEMALOCATION G4String("http://service-spi.web.cern.ch/service-spi/app/releases/GDML/GDML_2_10_0/src/GDMLSchema/gdml.xsd")
+
+class G4GDMLParser
+{
+  public:  // with description
+
+   G4GDMLParser() { xercesc::XMLPlatformUtils::Initialize(); }
+   ~G4GDMLParser() { xercesc::XMLPlatformUtils::Terminate(); }
+     //
+     // Parser constructor & destructor
+
+   inline void Read(const G4String& filename, G4bool Validate=true);
+     //
+     // Imports geometry with world-volume, specified by the GDML filename
+     // in input. Validation against schema is activated by default.
+
+   inline void ReadModule(const G4String& filename, G4bool Validate=true);
+     //
+     // Imports a single GDML module, specified by the GDML filename
+     // in input. Validation against schema is activated by default.
+
+   inline void Write(const G4String& filename,
+                     const G4VPhysicalVolume* const pvol = 0,
+                           G4bool storeReferences = true,
+                     const G4String& SchemaLocation = G4GDML_DEFAULT_SCHEMALOCATION);
+     //
+     // Exports on a GDML file, specified by 'filename' a geometry tree
+     // starting from 'pvol' as top volume. Uniqueness of stored entities
+     // is guaranteed by storing pointer-references by default.
+     // Alternative path for the schema location can be specified; by default
+     // the URL to the GDML web site is used.
+
+   inline G4LogicalVolume* ParseST(const G4String& name,
+                                         G4Material* medium,
+                                         G4Material* solid);
+     //
+     // Imports a tessellated geometry stored as STEP-Tools files
+     // 'name.geom' and 'name.tree'. It returns a pointer of a generated
+     // mother volume with 'medium' material associated, including the
+     // imported tessellated geometry with 'solid' material associated.
+
+   // Methods for Reader
+   //
+   inline G4double GetConstant(const G4String& name);
+   inline G4double GetVariable(const G4String& name);
+   inline G4double GetQuantity(const G4String& name);
+   inline G4ThreeVector GetPosition(const G4String& name);
+   inline G4ThreeVector GetRotation(const G4String& name);
+   inline G4ThreeVector GetScale(const G4String& name);
+   inline G4GDMLMatrix GetMatrix(const G4String& name);
+   inline G4LogicalVolume* GetVolume(const G4String& name);
+   inline G4VPhysicalVolume* GetWorldVolume(const G4String& setupName="Default");
+   inline G4GDMLAuxListType GetVolumeAuxiliaryInformation(const G4LogicalVolume* const logvol);
+
+   // Methods for Writer
+   //
+   inline void AddModule(const G4VPhysicalVolume* const physvol);
+   inline void AddModule(const G4int depth);
+   inline void SetAddPointerToName(G4bool set);
+
+  private:
+
+   G4GDMLReadStructure reader;
+   G4GDMLWriteStructure writer;
+
 };
 
+#include "G4GDMLParser.icc"
+
 #endif

trunk/source/persistency/gdml/src/G4GDMLEvaluator.cc

@@ -25 +25 @@
 //
 //
-// $Id: G4GDMLEvaluator.cc,v 1.11 2007/11/28 10:27:18 ztorzsok Exp $
+// $Id: G4GDMLEvaluator.cc,v 1.20 2008/07/16 15:46:34 gcosmo Exp $
 // GEANT4 tag $ Name:$
 //
@@ -34 +34 @@
 // --------------------------------------------------------------------
 
+#include <sstream>
 #include "G4GDMLEvaluator.hh"
 
-G4GDMLEvaluator::G4GDMLEvaluator() {
-
+G4GDMLEvaluator::G4GDMLEvaluator()
+{
    eval.clear();
    eval.setStdMath();
-   eval.setSystemOfUnits(1.e+3,1./1.60217733e-25,1.e+9,1./1.60217733e-10,1.0,1.0,1.0);
-}
-
-void G4GDMLEvaluator::defineConstant(const G4String& name,G4double value) {
-
-   if (eval.findVariable(name)) G4Exception("GDML: Constant or variable '"+name+"' is already defined!");
-
+   eval.setSystemOfUnits(meter,kilogram,second,ampere,kelvin,mole,candela);
+}
+
+void G4GDMLEvaluator::DefineConstant(const G4String& name, G4double value)
+{
+   if (eval.findVariable(name))
+   {
+     G4String error_msg = "Redefinition of constant or variable: "+name;
+     G4Exception("G4GDMLEvaluator::DefineConstant()", "InvalidExpression",
+                 FatalException, error_msg);
+   }
    eval.setVariable(name.c_str(),value);
 }
 
-void G4GDMLEvaluator::defineVariable(const G4String& name,G4double value) {
-
-   if (eval.findVariable(name)) G4Exception("GDML: Constant or variable '"+name+"' is already defined!");
-
+void G4GDMLEvaluator::DefineVariable(const G4String& name,G4double value)
+{
+   if (eval.findVariable(name))
+   {
+     G4String error_msg = "Redefinition of constant or variable: "+name;
+     G4Exception("G4GDMLEvaluator::DefineVariable()", "InvalidExpression",
+                 FatalException, error_msg);
+   }
    eval.setVariable(name.c_str(),value);
    variableList.push_back(name);
 }
 
-void G4GDMLEvaluator::setVariable(const G4String& name,G4double value) {
-
-   checkVariable(name);
-
+void G4GDMLEvaluator::DefineMatrix(const G4String& name,
+                                         G4int coldim,
+                                         std::vector<G4double> valueList)
+{
+   const G4int size = valueList.size();
+
+   if (size == 0)
+   {
+     G4String error_msg = "Matrix '"+name+"' is empty!";
+     G4Exception("G4GDMLEvaluator::DefineMatrix()", "InvalidSize",
+                 FatalException, error_msg);
+   }
+   if (size == 1)
+   {
+     G4String error_msg = "Matrix '" + name
+                        + "' has only one element! "
+                        + "Define a constant instead!!";
+     G4Exception("G4GDMLEvaluator::DefineMatrix()", "InvalidSize",
+                 FatalException, error_msg);
+   }
+   if (size % coldim != 0)
+   {
+     G4String error_msg = "Matrix '" + name + "' is not filled correctly!";
+     G4Exception("G4GDMLEvaluator::DefineMatrix()", "InvalidSize",
+                 FatalException, error_msg);
+   }
+
+   if ((size == coldim) || (coldim == 1))   // Row- or column matrix
+   {
+      for (G4int i=0;i<size;i++)
+      {
+         std::stringstream MatrixElementNameStream;
+         MatrixElementNameStream << name << "_" << i;
+         DefineConstant(MatrixElementNameStream.str(),valueList[i]);
+      }
+   }
+   else   // Normal matrix
+   {
+      const G4int rowdim = size/coldim;
+
+      for (G4int i=0;i<rowdim;i++)
+      {
+        for (G4int j=0;j<coldim;j++)
+        {
+          std::stringstream MatrixElementNameStream;
+          MatrixElementNameStream << name << "_" << i << "_" << j;
+          DefineConstant(MatrixElementNameStream.str(),valueList[coldim*i+j]);
+        }
+      }
+   }
+}
+
+void G4GDMLEvaluator::SetVariable(const G4String& name, G4double value)
+{
+   if (!IsVariable(name))
+   {
+     G4String error_msg = "Variable '" + name + "' is not defined!";
+     G4Exception("G4GDMLEvaluator::SetVariable()", "InvalidSetup",
+                 FatalException, error_msg);
+   }
    eval.setVariable(name.c_str(),value);
 }
 
-void G4GDMLEvaluator::checkVariable(const G4String& name) {
-
-   for (std::vector<G4String>::iterator iter = variableList.begin(); iter != variableList.end(); iter++) {
-
-      if (name == *iter) return;
-   }
-
-   G4Exception("GDML: Variable '"+name+"' is not defined!");
-}
-
-G4double G4GDMLEvaluator::Evaluate(const G4String& expression) {
+G4bool G4GDMLEvaluator::IsVariable(const G4String& name) const
+{
+   const size_t variableCount = variableList.size();
+
+   for (size_t i=0;i<variableCount;i++)
+   {
+      if (variableList[i] == name)  { return true; }
+   }
+
+   return false;
+}
+
+G4String G4GDMLEvaluator::SolveBrackets(const G4String& in)
+{
+   const std::string::size_type open = in.find("[",0);
+   const std::string::size_type close = in.find("]",0);
+
+   if (open==close) { return in; }
+
+   if (open>close)
+   {
+     G4String error_msg = "Bracket mismatch: " + in;
+     G4Exception("G4GDMLEvaluator::SolveBrackets()", "InvalidExpression",
+                 FatalException, error_msg);
+   }
+
+   std::string::size_type begin = open;
+   std::string::size_type end = 0;
+
+   std::string out;
+   out.append(in,0,open);
+   
+   do
+   {
+      end = in.find(",",begin+1);
+      if (end==std::string::npos)  { end = close; }
+
+      std::stringstream indexStream;
+      indexStream << "_" << EvaluateInteger(in.substr(begin+1,end-begin-1));
+
+      out.append(indexStream.str());
+
+      begin = end;
+
+   } while (end<close);
+
+   return out;
+}
+
+G4double G4GDMLEvaluator::Evaluate(const G4String& in)
+{
+   G4String expression = SolveBrackets(in);
 
    G4double value = 0.0;
 
-   if (!expression.empty()) {
-   
+   if (!expression.empty())
+   {
       value = eval.evaluate(expression.c_str());
 
-      if (eval.status() != HepTool::Evaluator::OK) {
-
+      if (eval.status() != HepTool::Evaluator::OK)
+      {
          eval.print_error();
-         G4Exception("Error in evaluator!");
+         G4String error_msg = "Error in expression: " + expression;
+         G4Exception("G4GDMLEvaluator::Evaluate()", "InvalidExpression",
+                     FatalException, error_msg);
       }
    }
-   
    return value;
 }
 
-G4int G4GDMLEvaluator::EvaluateInteger(const G4String& expression) {
+G4int G4GDMLEvaluator::EvaluateInteger(const G4String& expression)
+{
+   // This function is for evaluating integer expressions,
+   // like loop variables and matrix indices.
+   // Complains if the evaluated expression has a fractional
+   // part different from zero
 
    G4double value = Evaluate(expression);
@@ -100 +212 @@
    G4double frac = value - (G4double)whole;
 
-   if (frac != 0.0) G4Exception("GDML: Expression '"+expression+"' is expected to have an integer value!");
-
+   if (frac != 0.0)
+   {
+     G4String error_msg = "Expression '" + expression
+                        + "' is expected to have an integer value!";
+     G4Exception("G4GDMLEvaluator::EvaluateInteger()", "InvalidExpression",
+                 FatalException, error_msg);
+   }
    return whole;
 }
+
+G4double G4GDMLEvaluator::GetConstant(const G4String& name)
+{
+   if (IsVariable(name))
+   {
+     G4String error_msg = "Constant '" + name
+                        + "' is not defined! It is a variable!";
+     G4Exception("G4GDMLEvaluator::GetConstant()", "InvalidSetup",
+                 FatalException, error_msg);
+   }
+   if (!eval.findVariable(name))
+   {
+     G4String error_msg = "Constant '" + name + "' is not defined!";
+     G4Exception("G4GDMLEvaluator::GetConstant()", "InvalidSetup",
+                 FatalException, error_msg);
+   }
+   return Evaluate(name);
+}
+
+G4double G4GDMLEvaluator::GetVariable(const G4String& name)
+{
+   if (!IsVariable(name))
+   {
+     G4String error_msg = "Variable '" + name + "' is not a defined!";
+     G4Exception("G4GDMLEvaluator::GetVariable()", "InvalidSetup",
+                 FatalException, error_msg);
+   }
+   return Evaluate(name);
+}