small updates

doc/src/variable.rst

@@ -929,13 +929,14 @@ The is_file(name) function is a test whether *name* is a (readable) file
 and returns 1 in this case, otherwise it returns 0.  For that *name*
 is taken as a literal string and must not have any blanks in it.
 
-The extract_setting(name) function enables access to basic settings
+The extract_setting(name) function enables access to basic settings for
-for the LAMMPS executable and the running simulation via calling the
+the LAMMPS executable and the running simulation via calling the
 :cpp:func:`lammps_extract_setting` library function.  For example, the
-number of processors (MPI ranks) being used by the simulation or the
+number of processors (MPI ranks) being used by the simulation or the MPI
-procID (for this processor) can be queried.  For the full list of
+process ID (for this processor) can be queried, or the number of atom
-available keywords *name* and their meaning, see the documentation for
+types, bond types and so on. For the full list of available keywords
-extract_setting() via the link in this paragraph.
+*name* and their meaning, see the documentation for extract_setting()
+via the link in this paragraph.
 
 ----------
 

src/library.cpp

@@ -950,6 +950,14 @@ not recognized, the function returns -1.
      - number of dihedral types
    * - nimpropertypes
      - number of improper types
+   * - nellipsoids
+     - number of atoms that have ellipsoid data
+   * - nlines
+     - number of atoms that have line data (see :doc:`pair style line/lj <pair_line_lj>`)
+   * - ntris
+     - number of atoms that have triangle data (see :doc:`pair style tri/lj <pair_tri_lj>`)
+   * - nbodies
+     - number of atoms that have body data (see :doc:`the Body particle HowTo <Howto_body>`)
 
 .. _extract_atom_flags:
 
@@ -1021,6 +1029,10 @@ int lammps_extract_setting(void *handle, const char *keyword)
   if (strcmp(keyword,"nangletypes") == 0) return lmp->atom->nangletypes;
   if (strcmp(keyword,"ndihedraltypes") == 0) return lmp->atom->ndihedraltypes;
   if (strcmp(keyword,"nimpropertypes") == 0) return lmp->atom->nimpropertypes;
+  if (strcmp(keyword,"nellipsoids") == 0) return lmp->atom->nellipsoids;
+  if (strcmp(keyword,"nlines") == 0) return lmp->atom->nlines;
+  if (strcmp(keyword,"ntris") == 0) return lmp->atom->ntris;
+  if (strcmp(keyword,"nbodies") == 0) return lmp->atom->nbodies;
 
   if (strcmp(keyword,"molecule_flag") == 0) return lmp->atom->molecule_flag;
   if (strcmp(keyword,"q_flag") == 0) return lmp->atom->q_flag;