add Pair::extract_atom() method

src/AMOEBA/pair_amoeba.cpp

@@ -2077,16 +2077,25 @@ void *PairAmoeba::extract(const char *str, int &dim)
   if (strcmp(str,"opbend_pentic") == 0) return (void *) &opbend_pentic;
   if (strcmp(str,"opbend_sextic") == 0) return (void *) &opbend_sextic;
 
-  // peratom requests from FixPair
-  // return dim = # of quantites per atom
-  //   0 = per-atom vector
-  //   1 or more = # of columns in per-atom array
+  return nullptr;
+}
 
+/* ----------------------------------------------------------------------
+   peratom requests from FixPair
+   return ptr to requested data
+   also return ncol = # of quantites per atom
+     0 = per-atom vector
+     1 or more = # of columns in per-atom array
+   return NULL if str is not recognized
+---------------------------------------------------------------------- */
+
+void *PairAmoeba::extract_peratom(const char *str, int &ncol)
+{
   if (strcmp(str,"uind") == 0) {
-    dim = 3;
+    ncol = 3;
     return (void *) uind;
   } else if (strcmp(str,"uinp") == 0) {
-    dim = 3;
+    ncol = 3;
     return (void *) uinp;
   }
 

src/AMOEBA/pair_amoeba.h

@@ -50,6 +50,7 @@ class PairAmoeba : public Pair {
   void unpack_reverse_grid(int, void *, int, int *) override;
 
   void *extract(const char *, int &) override;
+  void *extract_peratom(const char *, int &) override;
   double memory_usage() override;
 
  protected:

src/MANYBODY/pair_eam.cpp

@@ -934,16 +934,25 @@ void *PairEAM::extract(const char *str, int &dim)
   dim = 2;
   if (strcmp(str,"scale") == 0) return (void *) scale;
 
-  // peratom requests from FixPair
-  // return dim = # of quantites per atom
-  //   0 = per-atom vector
-  //   1 or more = # of columns in per-atom array
+  return nullptr;
+}
 
+/* ----------------------------------------------------------------------
+   peratom requests from FixPair
+   return ptr to requested data
+   also return ncol = # of quantites per atom
+     0 = per-atom vector
+     1 or more = # of columns in per-atom array
+   return NULL if str is not recognized
+---------------------------------------------------------------------- */
+
+void *PairEAM::extract_peratom(const char *str, int &ncol)
+{
   if (strcmp(str,"rho") == 0) {
-    dim = 0;
+    ncol = 0;
     return (void *) rho;
   } else if (strcmp(str,"fp") == 0) {
-    dim = 0;
+    ncol = 0;
     return (void *) fp;
   }
 

src/MANYBODY/pair_eam.h

@@ -53,6 +53,7 @@ class PairEAM : public Pair {
   double init_one(int, int) override;
   double single(int, int, int, int, double, double, double, double &) override;
   void *extract(const char *, int &) override;
+  void *extract_peratom(const char *, int &) override;
 
   int pack_forward_comm(int, int *, double *, int, int *) override;
   void unpack_forward_comm(int, int, double *) override;

src/fix_pair.cpp

@@ -83,15 +83,15 @@ FixPair::FixPair(LAMMPS *lmp, int narg, char **arg) :
 
   triggerptr = new int*[nfield];
 
-  int dim;
   ncols = 0;
 
   for (int ifield = 0; ifield < nfield; ifield++) {
     int columns = 0;         // set in case fieldname not recognized by pstyle
-    void *pvoid = pstyle->extract(fieldname[ifield],columns);
+    void *pvoid = pstyle->extract_peratom(fieldname[ifield],columns);
     if (columns) ncols += columns;
     else ncols++;
     if (trigger[ifield]) {
+      int dim;
       triggerptr[ifield] = (int *) pstyle->extract(triggername[ifield],dim);
       if (!triggerptr[ifield]) 
         error->all(FLERR,"Fix pair pair style cannot extract {}",
@@ -222,7 +222,7 @@ void FixPair::post_force(int /*vflag*/)
   int columns;
 
   for (int ifield = 0; ifield < nfield; ifield++) {
-    void *pvoid = pstyle->extract(fieldname[ifield],columns);
+    void *pvoid = pstyle->extract_peratom(fieldname[ifield],columns);
     if (pvoid == nullptr) 
       error->all(FLERR,"Fix pair pair style cannot extract {}",fieldname[ifield]);
 

src/pair.h

@@ -215,6 +215,7 @@ class Pair : protected Pointers {
   // specific child-class methods for certain Pair styles
 
   virtual void *extract(const char *, int &) { return nullptr; }
+  virtual void *extract_peratom(const char *, int &) { return nullptr; }
   virtual void swap_eam(double *, double **) {}
   virtual void reset_dt() {}
   virtual void min_xf_pointers(int, double **, double **) {}