implement set_time command

doc/src/Commands_all.rst

@@ -105,6 +105,7 @@ An alphabetic list of all general LAMMPS commands.
    * :doc:`run <run>`
    * :doc:`run_style <run_style>`
    * :doc:`set <set>`
+   * :doc:`set_time <set_time>`
    * :doc:`shell <shell>`
    * :doc:`special_bonds <special_bonds>`
    * :doc:`suffix <suffix>`

doc/src/commands_list.rst

@@ -96,6 +96,7 @@ Commands
    run
    run_style
    set
+   set_time
    shell
    special_bonds
    suffix

doc/src/set_time.rst

@@ -0,0 +1,44 @@
+.. index:: set_time
+
+set_time command
+================
+
+Syntax
+""""""
+
+.. parsed-literal::
+
+   set_time t
+
+* t = current simulation time (time units)
+
+Examples
+""""""""
+
+.. code-block:: LAMMPS
+
+   time 0.0
+   time 10.5
+
+Description
+"""""""""""
+
+Set the current accumulated simulation time for subsequent molecular
+dynamics simulations.  See the :doc:`units <units>` command for the time
+units associated with each choice of units that LAMMPS supports.
+
+
+Restrictions
+""""""""""""
+ none
+
+Related commands
+""""""""""""""""
+
+:doc:`reset_timestep <reset_timestep>`, :doc:`timestep <timestep>`,
+:doc:`fix dt/reset <fix_dt_reset>`, :doc:`units <units>`
+
+Default
+"""""""
+
+0.0 at the beginning of the first run.

src/input.cpp

@@ -773,6 +773,7 @@ int Input::execute_command()
   else if (!strcmp(command,"reset_timestep")) reset_timestep();
   else if (!strcmp(command,"restart")) restart();
   else if (!strcmp(command,"run_style")) run_style();
+  else if (!strcmp(command,"set_time")) set_time();
   else if (!strcmp(command,"special_bonds")) special_bonds();
   else if (!strcmp(command,"suffix")) suffix();
   else if (!strcmp(command,"thermo")) thermo();
@@ -1772,6 +1773,16 @@ void Input::run_style()
 
 /* ---------------------------------------------------------------------- */
 
+void Input::set_time()
+{
+  if (narg != 1) error->all(FLERR,"Illegal set_time command");
+
+  update->atime = utils::numeric(FLERR,arg[0],false,lmp);
+  update->atimestep = update->ntimestep;
+}
+
+/* ---------------------------------------------------------------------- */
+
 void Input::special_bonds()
 {
   // store 1-3,1-4 and dihedral/extra flag values before change

src/input.h

@@ -131,6 +131,7 @@ class Input : protected Pointers {
   void reset_timestep();
   void restart();
   void run_style();
+  void set_time();
   void special_bonds();
   void suffix();
   void thermo();

src/lmprestart.h

@@ -17,7 +17,7 @@
 #define MAGIC_STRING "LammpS RestartT"
 #define ENDIAN 0x0001
 #define ENDIANSWAP 0x1000
-#define FORMAT_REVISION 2
+#define FORMAT_REVISION 3
 
 enum{VERSION,SMALLINT,TAGINT,BIGINT,
      UNITS,NTIMESTEP,DIMENSION,NPROCS,PROCGRID,
@@ -37,7 +37,8 @@ enum{VERSION,SMALLINT,TAGINT,BIGINT,
      COMM_MODE,COMM_CUTOFF,COMM_VEL,NO_PAIR,
      EXTRA_BOND_PER_ATOM,EXTRA_ANGLE_PER_ATOM,EXTRA_DIHEDRAL_PER_ATOM,
      EXTRA_IMPROPER_PER_ATOM,EXTRA_SPECIAL_PER_ATOM,ATOM_MAXSPECIAL,
-     NELLIPSOIDS,NLINES,NTRIS,NBODIES};
+     NELLIPSOIDS,NLINES,NTRIS,NBODIES,
+     ATIME,ATIMESTEP};
 
 #define LB_FACTOR 1.1
 

src/read_restart.cpp

@@ -594,21 +594,18 @@ void ReadRestart::header()
     if (flag == VERSION) {
       char *version = read_string();
       if (me == 0)
-        utils::logmesg(lmp,"  restart file = {}, LAMMPS = {}\n",
+        utils::logmesg(lmp,"  restart file = {}, LAMMPS = {}\n", version, lmp->version);
-                       version,lmp->version);
       delete[] version;
 
       // we have no forward compatibility, thus exit with error
 
       if (revision > FORMAT_REVISION)
-        error->all(FLERR,"Restart file format revision incompatible "
+        error->all(FLERR,"Restart file format revision incompatible with current LAMMPS version");
-                   "with current LAMMPS version");
 
       // warn when attempting to read older format revision
 
       if ((me == 0) && (revision < FORMAT_REVISION))
-        error->warning(FLERR,"Old restart file format revision. "
+        error->warning(FLERR,"Old restart file format revision. Switching to compatibility mode.");
-                       "Switching to compatibility mode.");
 
     // check lmptype.h sizes, error if different
 
@@ -654,8 +651,8 @@ void ReadRestart::header()
     } else if (flag == NPROCS) {
       nprocs_file = read_int();
       if (nprocs_file != comm->nprocs && me == 0)
-        error->warning(FLERR,"Restart file used different # of processors: "
+        error->warning(FLERR,"Restart file used different # of processors: {} vs. {}",
-                       "{} vs. {}",nprocs_file,comm->nprocs);
+                       nprocs_file,comm->nprocs);
 
     // don't set procgrid, warn if different
 
@@ -681,16 +678,14 @@ void ReadRestart::header()
       int newton_pair_file = read_int();
       if (force->newton_pair != 1) {
         if (newton_pair_file != force->newton_pair && me == 0)
-          error->warning(FLERR,
+          error->warning(FLERR, "Restart file used different newton pair setting, "
-                         "Restart file used different newton pair setting, "
                          "using input script value");
       }
     } else if (flag == NEWTON_BOND) {
       int newton_bond_file = read_int();
       if (force->newton_bond != 1) {
         if (newton_bond_file != force->newton_bond && me == 0)
-          error->warning(FLERR,
+          error->warning(FLERR, "Restart file used different newton bond setting, "
-                         "Restart file used different newton bond setting, "
                          "using restart file value");
       }
       force->newton_bond = newton_bond_file;
@@ -721,8 +716,7 @@ void ReadRestart::header()
             boundary[2][0] != domain->boundary[2][0] ||
             boundary[2][1] != domain->boundary[2][1]) {
           if (me == 0)
-            error->warning(FLERR,
+            error->warning(FLERR, "Restart file used different boundary settings, "
-                           "Restart file used different boundary settings, "
                            "using restart file values");
         }
       }
@@ -864,6 +858,13 @@ void ReadRestart::header()
     } else if (flag == NBODIES) {
       atom->nbodies = read_bigint();
 
+    } else if (flag == ATIMESTEP) {
+      update->atimestep = read_bigint();
+    } else if (flag == ATIME) {
+      update->atime = read_double();
+
+    // set dimension from restart file
+
       // for backward compatibility
     } else if (flag == EXTRA_SPECIAL_PER_ATOM) {
       force->special_extra = read_int();

src/update.h

@@ -27,7 +27,7 @@ class Update : protected Pointers {
   bigint ntimestep;              // current step (dynamics or min iterations)
   int nsteps;                    // # of steps to run (dynamics or min iter)
   int whichflag;                 // 0 for unset, 1 for dynamics, 2 for min
-  double atime;                  // simulation time at atime_step
+  double atime;                  // simulation time at atimestep
   bigint atimestep;              // last timestep atime was updated
   bigint firststep, laststep;    // 1st & last step of this run
   bigint beginstep, endstep;     // 1st and last step of multiple runs

src/write_restart.cpp

@@ -118,8 +118,7 @@ void WriteRestart::command(int narg, char **arg)
 
 /* ---------------------------------------------------------------------- */
 
-void WriteRestart::multiproc_options(int multiproc_caller, int mpiioflag_caller,
+void WriteRestart::multiproc_options(int multiproc_caller, int mpiioflag_caller, int narg, char **arg)
-                                     int narg, char **arg)
 {
   multiproc = multiproc_caller;
   mpiioflag = mpiioflag_caller;
@@ -127,14 +126,12 @@ void WriteRestart::multiproc_options(int multiproc_caller, int mpiioflag_caller,
   // error checks
 
   if (multiproc && mpiioflag)
-    error->all(FLERR,
+    error->all(FLERR,"Restart file MPI-IO output not allowed with % in filename");
-               "Restart file MPI-IO output not allowed with % in filename");
 
   if (mpiioflag) {
     mpiio = new RestartMPIIO(lmp);
     if (!mpiio->mpiio_exists)
-      error->all(FLERR,"Writing to MPI-IO filename when "
+      error->all(FLERR,"Writing to MPI-IO filename when MPIIO package is not installed");
-                 "MPIIO package is not installed");
   }
 
   // defaults for multiproc file writing
@@ -158,8 +155,7 @@ void WriteRestart::multiproc_options(int multiproc_caller, int mpiioflag_caller,
     if (strcmp(arg[iarg],"fileper") == 0) {
       if (iarg+2 > narg) error->all(FLERR,"Illegal write_restart command");
       if (!multiproc)
-        error->all(FLERR,"Cannot use write_restart fileper "
+        error->all(FLERR,"Cannot use write_restart fileper without % in restart file name");
-                   "without % in restart file name");
       int nper = utils::inumeric(FLERR,arg[iarg+1],false,lmp);
       if (nper <= 0) error->all(FLERR,"Illegal write_restart command");
 
@@ -176,8 +172,7 @@ void WriteRestart::multiproc_options(int multiproc_caller, int mpiioflag_caller,
     } else if (strcmp(arg[iarg],"nfile") == 0) {
       if (iarg+2 > narg) error->all(FLERR,"Illegal write_restart command");
       if (!multiproc)
-        error->all(FLERR,"Cannot use write_restart nfile "
+        error->all(FLERR,"Cannot use write_restart nfile without % in restart file name");
-                   "without % in restart file name");
       int nfile = utils::inumeric(FLERR,arg[iarg+1],false,lmp);
       if (nfile <= 0) error->all(FLERR,"Illegal write_restart command");
       nfile = MIN(nfile,nprocs);
@@ -510,6 +505,11 @@ void WriteRestart::header()
   write_bigint(NTRIS,atom->ntris);
   write_bigint(NBODIES,atom->nbodies);
 
+  // write out current simulation time. added 3 May 2022
+
+  write_bigint(ATIMESTEP,update->atimestep);
+  write_double(ATIME,update->atime);
+
   // -1 flag signals end of header
 
   int flag = -1;

unittest/commands/test_simple_commands.cpp

@@ -241,6 +241,40 @@ TEST_F(SimpleCommandsTest, ResetTimestep)
     TEST_FAILURE(".*ERROR: Expected integer .*", command("reset_timestep xxx"););
 }
 
+TEST_F(SimpleCommandsTest, SetTime)
+{
+    ASSERT_EQ(lmp->update->ntimestep, 0);
+    ASSERT_EQ(lmp->update->atimestep, 0);
+    ASSERT_DOUBLE_EQ(lmp->update->atime, 0.0);
+
+    BEGIN_HIDE_OUTPUT();
+    command("set_time 10.0");
+    END_HIDE_OUTPUT();
+    ASSERT_EQ(lmp->update->atimestep, 0);
+    ASSERT_DOUBLE_EQ(lmp->update->atime, 10.0);
+
+    BEGIN_HIDE_OUTPUT();
+    command("reset_timestep 10");
+    command("set_time 10.0");
+    END_HIDE_OUTPUT();
+    ASSERT_EQ(lmp->update->ntimestep, 10);
+    ASSERT_EQ(lmp->update->atimestep, 10);
+    ASSERT_DOUBLE_EQ(lmp->update->atime, 10.0);
+
+    BEGIN_HIDE_OUTPUT();
+    command("reset_timestep 0");
+    command("set_time 10.0");
+    command("reset_timestep 10");
+    END_HIDE_OUTPUT();
+    ASSERT_EQ(lmp->update->ntimestep, 10);
+    ASSERT_EQ(lmp->update->atimestep, 10);
+    ASSERT_DOUBLE_EQ(lmp->update->atime, 10.0 + lmp->update->dt * 10);
+
+    TEST_FAILURE(".*ERROR: Illegal set_time .*", command("set_time"););
+    TEST_FAILURE(".*ERROR: Illegal set_time .*", command("set_time 10 10"););
+    TEST_FAILURE(".*ERROR: Expected floating .*", command("set_time xxx"););
+}
+
 TEST_F(SimpleCommandsTest, Suffix)
 {
     ASSERT_EQ(lmp->suffix_enable, 0);