additional fix external hooks for calling programs

src/fix_external.cpp

@@ -30,7 +30,7 @@ enum{PF_CALLBACK,PF_ARRAY};
 
 FixExternal::FixExternal(LAMMPS *lmp, int narg, char **arg) :
   Fix(lmp, narg, arg),
-  fexternal(NULL)
+  fexternal(NULL), caller_vector(NULL)
 {
   if (narg < 4) error->all(FLERR,"Illegal fix external command");
 
@@ -62,6 +62,11 @@ FixExternal::FixExternal(LAMMPS *lmp, int narg, char **arg) :
   atom->add_callback(0);
 
   user_energy = 0.0;
+
+  // optional vector of values provided by caller
+  // vector_flag and size_vector are setup via set_vector_length()
+
+  caller_vector = NULL;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -73,6 +78,7 @@ FixExternal::~FixExternal()
   atom->delete_callback(id,0);
 
   memory->destroy(fexternal);
+  delete [] caller_vector;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -167,10 +173,15 @@ void FixExternal::min_post_force(int vflag)
   post_force(vflag);
 }
 
+// ----------------------------------------------------------------------
+// "set" methods caller can invoke directly
+// ----------------------------------------------------------------------
+
 /* ----------------------------------------------------------------------
    caller invokes this method to set its contribution to global energy
-   do not just return if eflag_global is not set
-     input script could access this quantity via compute_scalar()
+   unlike other energy/virial set methods:
+     do not just return if eflag_global is not set
+     b/c input script could access this quantity via compute_scalar()
      even if eflag is not set on a particular timestep
 ------------------------------------------------------------------------- */
 
@@ -220,6 +231,34 @@ void FixExternal::set_virial_peratom(double **caller_virial)
       vatom[i][j] = caller_virial[i][j];
 }
 
+/* ----------------------------------------------------------------------
+   caller invokes this method to set length of vector of values
+   assume all vector values are extensive, could make this an option
+------------------------------------------------------------------------- */
+
+void FixExternal::set_vector_length(int n)
+{
+  delete [] caller_vector;
+
+  vector_flag = 1;
+  size_vector = n;
+  extvector = 1;
+
+  caller_vector = new double[n];
+}
+
+/* ----------------------------------------------------------------------
+   caller invokes this method to set Index value in vector
+   index ranges from 1 to N inclusive
+------------------------------------------------------------------------- */
+
+void FixExternal::set_vector(int index, double value)
+{
+  if (index >= size_vector)
+    error->all(FLERR,"Invalid set_vector index in fix external");
+  caller_vector[index-1] = value;
+}
+
 /* ----------------------------------------------------------------------
    potential energy of added force
    up to user to set it via set_energy()
@@ -230,6 +269,16 @@ double FixExternal::compute_scalar()
   return user_energy;
 }
 
+/* ----------------------------------------------------------------------
+   arbitrary value computed by caller
+   up to user to set it via set_vector()
+------------------------------------------------------------------------- */
+
+double FixExternal::compute_vector(int n)
+{
+  return caller_vector[n];
+}
+
 /* ----------------------------------------------------------------------
    memory usage of local atom-based array
 ------------------------------------------------------------------------- */