Allow individual reductions on variables by parsing the options string

in the 'IOBasic::outScalar_vars' parameter.
This closes PR CactusBase/895.


git-svn-id: http://svn.cactuscode.org/arrangements/CactusBase/IOBasic/trunk@116 b589c3ab-70e8-4b4d-a09f-cba2dd200880

4 files changed, 423 insertions, 288 deletions

diff --git a/src/OutputScalar.c b/src/OutputScalar.c
index 1281cff..9169821 100644
--- a/src/OutputScalar.c
+++ b/src/OutputScalar.c
@@ -27,7 +27,6 @@ CCTK_FILEVERSION(CactusBase_IOBasic_OutputScalar_c)
  ********************    Internal Routines   ************************
  ********************************************************************/
 static void CheckSteerableParameters (iobasicGH *myGH);
-static void SetOutputFlag (int vindex, const char *optstring, void *arg);
 
 
 /*@@
@@ -38,8 +37,7 @@ static void SetOutputFlag (int vindex, const char *optstring, void *arg);
                Loops over all variables and outputs them if necessary
    @enddesc
    @calls      IOBasic_TimeForScalarOutput
-               IOBasic_WriteScalarGS
-               IOBasic_WriteScalarGA
+               IOBasic_WriteScalar
 
    @var        GH
    @vdesc      Pointer to CCTK GH
@@ -55,7 +53,7 @@ static void SetOutputFlag (int vindex, const char *optstring, void *arg);
 @@*/
 int IOBasic_ScalarOutputGH (const cGH *GH)
 {
-  int i, vindex, retval;
+  int vindex, retval;
   const char *name;
   iobasicGH *myGH;
 
@@ -91,15 +89,7 @@ int IOBasic_ScalarOutputGH (const cGH *GH)
 #endif
 
     /* Make the IO call */
-    if (CCTK_GroupTypeFromVarI (vindex) == CCTK_SCALAR)
-    {
-      i = IOBasic_WriteScalarGS (GH, vindex, name);
-    }
-    else
-    {
-      i = IOBasic_WriteScalarGA (GH, vindex, name);
-    }
-    if (i == 0)
+    if (IOBasic_WriteScalar (GH, vindex, name) == 0)
     {
       /* Register GF as having 0D output this iteration */
       myGH->outScalar_last [vindex] = GH->cctk_iteration;
@@ -111,66 +101,6 @@ int IOBasic_ScalarOutputGH (const cGH *GH)
 }
 
 
-/*@@
-   @routine    IOBasic_ScalarOutputVarAs
-   @date       Sat March 6 1999
-   @author     Gabrielle Allen
-   @desc
-               Unconditional output of a variable using IOBasic's SCALAR
-               output method
-   @enddesc
-   @calls      IOBasic_WriteScalarGS
-               IOBasic_WriteScalarGA
-
-   @var        GH
-   @vdesc      Pointer to CCTK GH
-   @vtype      const cGH *
-   @vio        in
-   @endvar
-   @var        fullname
-   @vdesc      complete name of variable to output
-   @vtype      const char *
-   @vio        in
-   @endvar
-   @var        alias
-   @vdesc      alias name of variable to output (used to generate output filename)
-   @vtype      const char *
-   @vio        in
-   @endvar
-
-   @returntype int
-   @returndesc
-               return code of @seeroutine IOBasic_WriteScalarGS or
-               @seeroutine IOBasic_WriteScalarGA
-   @endreturndesc
-@@*/
-int IOBasic_ScalarOutputVarAs (const cGH *GH, const char *fullname, const char *alias)
-{
-  int vindex, retval;
-
-
-  vindex = CCTK_VarIndex (fullname);
-
-#ifdef IOBASIC_DEBUG
-  printf("\nIn IOBasic_ScalarOutputVarAs\n-------------------\n");
-  printf("  Fullname = -%s-\n",fullname);
-  printf("  Alias = -%s-\n",alias);
-  printf("  Index = %d\n",vindex);
-#endif
-
-  if (CCTK_GroupTypeFromVarI (vindex) == CCTK_SCALAR)
-  {
-    retval = IOBasic_WriteScalarGS (GH, vindex, alias);
-  }
-  else
-  {
-    retval = IOBasic_WriteScalarGA (GH, vindex, alias);
-  }
-
-  return (retval);
-}
-
-
  /*@@
    @routine    IOBasic_TimeForScalarOutput
    @date       Sat March 6 1999
@@ -198,45 +128,37 @@ int IOBasic_ScalarOutputVarAs (const cGH *GH, const char *fullname, const char *
 @@*/
 int IOBasic_TimeForScalarOutput (const cGH *GH, int vindex)
 {
-  int return_type;
-  iobasicGH *myGH;
+  int retval;
   char *fullname;
+  iobasicGH *myGH;
 
 
-  /* Default is do not do output */
-  return_type = 0;
-
   /* Get the GH extension for IOBasic */
   myGH = (iobasicGH *) CCTK_GHExtension (GH, "IOBasic");
 
   CheckSteerableParameters (myGH);
 
   /* check if any output was requested */
-  if (myGH->outScalar_every <= 0)
+  if (myGH->outScalar_every <= 0 || GH->cctk_iteration % myGH->outScalar_every
+      || myGH->scalar_reductions[vindex].num_reductions == 0)
   {
-    return (0);
+    retval = 0;
   }
-
-  /* Check if this variable should be output */
-  if (myGH->do_outScalar [vindex] &&
-      (GH->cctk_iteration % myGH->outScalar_every) == 0)
+  else
   {
     /* Check if variable wasn't already output this iteration */
-    if (myGH->outScalar_last [vindex] == GH->cctk_iteration)
+    retval = myGH->outScalar_last [vindex] != GH->cctk_iteration;
+    if (! retval)
     {
       fullname = CCTK_FullName (vindex);
       CCTK_VWarn (5, __LINE__, __FILE__, CCTK_THORNSTRING,
-                  "Already done IOBasic scalar output for '%s' in "
-                  "current iteration (probably via triggers)", fullname);
+                  "Already done scalar output for '%s' in current iteration "
+                  "(probably via triggers)", fullname);
       free (fullname);
     }
-    else
-    {
-      return_type = 1;
-    }
   }
 
-  return (return_type);
+  return (retval);
 }
 
 
@@ -262,8 +184,7 @@ int IOBasic_TimeForScalarOutput (const cGH *GH, int vindex)
 
    @returntype int
    @returndesc
-               return code of @seeroutine IOBasic_WriteScalarGS or
-               @seeroutine IOBasic_WriteScalarGA
+               return code of @seeroutine IOBasic_WriteScalar
    @endreturndesc
 @@*/
 int IOBasic_TriggerScalarOutput (const cGH *GH, int vindex)
@@ -285,14 +206,7 @@ int IOBasic_TriggerScalarOutput (const cGH *GH, int vindex)
 #endif
 
   /* Do the Scalar output */
-  if (CCTK_GroupTypeFromVarI (vindex) == CCTK_SCALAR)
-  {
-    retval = IOBasic_WriteScalarGS (GH, vindex, name);
-  }
-  else
-  {
-    retval = IOBasic_WriteScalarGA (GH, vindex, name);
-  }
+  retval = IOBasic_WriteScalar (GH, vindex, name);
 
   if (retval == 0)
   {
@@ -304,62 +218,120 @@ int IOBasic_TriggerScalarOutput (const cGH *GH, int vindex)
 }
 
 
-/**************************** local functions ******************************/
-/* check if steerable parameters have changed */
+/********************************************************************
+ ********************    Internal Routines   ************************
+ ********************************************************************/
+ /*@@
+   @routine    CheckSteerableParameters
+   @date       Tue 31 Jul 2001
+   @author     Thomas Radke
+   @desc
+               Re-evaluates 'IOBasic::outScalar_every' and/or 'IO::out_every'
+               resp. to set myGH->outScalar_every to the frequency of scalar
+               output. Re-evaluates 'IOBasic::outScalar_vars' and
+               'IOBasic::outScalar_reductions'.
+   @enddesc
+   @calls      CCTK_ParameterQueryTimesSet
+
+   @var        myGH
+   @vdesc      Pointer to IOBasic's GH extension
+   @vtype      iobasicGH *
+   @vio        in
+   @endvar
+@@*/
 static void CheckSteerableParameters (iobasicGH *myGH)
 {
-  int i, num_vars, out_old;
-  int times_set;
-  char *fullname, *msg, *oldmsg;
-  static int outScalar_vars_lastset = -1;
+  int vindex, out_old, times_set, update_reductions_list, num_vars;
+  iobasic_reduction_t *reduction, *next;
+  static int outScalar_vars_lastset       = -1;
+  static int outScalar_reductions_lastset = -1;
+  iobasic_parseinfo_t info;
+  char *msg, *oldmsg, *fullname;
   DECLARE_CCTK_PARAMETERS
 
 
-  /* How often to output */
+  /* how often to output */
   out_old = myGH->outScalar_every;
   myGH->outScalar_every = out_every > 0 ? out_every : -1;
   if (outScalar_every > 0)
   {
     myGH->outScalar_every = outScalar_every;
   }
-
-  if (myGH->outScalar_every != out_old)
+  if (myGH->outScalar_every != out_old && ! CCTK_Equals (newverbose, "none"))
   {
-    if (CCTK_Equals (newverbose, "standard") ||
-        CCTK_Equals (newverbose, "full"))
+    if (myGH->outScalar_every > 0)
+    {
+      CCTK_VInfo (CCTK_THORNSTRING, "Scalar: Periodic output every %d "
+                  "iterations", myGH->outScalar_every);
+    }
+    else
     {
-      CCTK_VInfo (CCTK_THORNSTRING, "Scalar: Output every %d iterations",
-                  myGH->outScalar_every);
+      CCTK_INFO ("Scalar: Periodic output turned off");
     }
   }
 
-  /* re-parse the 'outScalar_vars' parameter if it was changed */
+  /* return if there's nothing to do */
+  if (myGH->outScalar_every <= 0)
+  {
+    return;
+  }
+
+  /* check if the 'outScalar_reductions' parameter if it was changed */
+  times_set = CCTK_ParameterQueryTimesSet ("outScalar_reductions",
+                                           CCTK_THORNSTRING);
+  update_reductions_list = times_set != outScalar_reductions_lastset;
+  outScalar_reductions_lastset = times_set;
+
+  /* check if the 'outScalar_vars' parameter if it was changed */
   times_set = CCTK_ParameterQueryTimesSet ("outScalar_vars", CCTK_THORNSTRING);
-  if (times_set != outScalar_vars_lastset)
+  update_reductions_list |= times_set != outScalar_vars_lastset;
+  outScalar_vars_lastset = times_set;
+
+  if (update_reductions_list)
   {
+    /* free old reduction lists ... */
     num_vars = CCTK_NumVars ();
-    memset (myGH->do_outScalar, 0, num_vars);
-    CCTK_TraverseString (outScalar_vars, SetOutputFlag, myGH->do_outScalar,
-                         CCTK_GROUP_OR_VAR);
+    for (vindex = 0; vindex < num_vars; vindex++)
+    {
+      if (myGH->scalar_reductions[vindex].num_reductions > 0)
+      {
+        myGH->scalar_reductions[vindex].num_reductions = 0;
+        reduction = myGH->scalar_reductions[vindex].reductions;
+        while (reduction)
+        {
+          next = reduction->next;
+          free (reduction->name);
+          free (reduction);
+          reduction = next;
+        }
+      }
+    }
 
-    if (myGH->outScalar_every &&
-        (CCTK_Equals (newverbose, "standard") ||
-         CCTK_Equals (newverbose, "full")))
+    /* ... and create new ones */
+    info.reduction_list = myGH->scalar_reductions;
+    info.reductions_string = outScalar_reductions;
+    if (CCTK_TraverseString (outScalar_vars, IOBasic_AssignReductionList, &info,
+                             CCTK_GROUP_OR_VAR) < 0)
+    {
+      CCTK_WARN (1, "Failed to parse 'IOBasic::outScalar_vars' parameter");
+    }
+    else if (! CCTK_Equals (newverbose, "none"))
     {
       msg = NULL;
-      for (i = 0; i < num_vars; i++)
+      for (vindex = 0; vindex < num_vars; vindex++)
       {
-        if (myGH->do_outScalar[i])
+        if (myGH->scalar_reductions[vindex].num_reductions)
         {
-          fullname = CCTK_FullName (i);
+          fullname = CCTK_FullName (vindex);
           if (! msg)
           {
-            Util_asprintf (&msg, "Scalar: Output requested for %s", fullname);
+            Util_asprintf (&msg, "Scalar: Periodic output requested for '%s'",
+                           fullname);
           }
           else
           {
             oldmsg = msg;
-            Util_asprintf (&msg, "%s %s", oldmsg, fullname);
+            Util_asprintf (&msg, "%s, '%s'", oldmsg, fullname);
             free (oldmsg);
           }
           free (fullname);
@@ -371,26 +343,5 @@ static void CheckSteerableParameters (iobasicGH *myGH)
         free (msg);
       }
     }
-
-    /* Save the last setting of 'outScalar_vars' parameter */
-    outScalar_vars_lastset = times_set;
-  }
-
-}
-
-
-/* callback for CCTK_TraverseString() to set the output flag
-   for the given variable */
-static void SetOutputFlag (int vindex, const char *optstring, void *arg)
-{
-  char *flags = (char *) arg;
-
-
-  flags[vindex] = 1;
-
-  if (optstring)
-  {
-    CCTK_VWarn (5, __LINE__, __FILE__, CCTK_THORNSTRING,
-                "Optional string '%s' in variable name ignored", optstring);
   }
 }
diff --git a/src/Startup.c b/src/Startup.c
index 30c6bc4..3821d86 100644
--- a/src/Startup.c
+++ b/src/Startup.c
@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <ctype.h>
 
 #include "cctk.h"
 #include "cctk_Parameters.h"
@@ -73,7 +74,6 @@ void IOBasic_Startup (void)
 
    @calls     CCTK_RegisterIOMethod
               CCTK_RegisterIOMethodOutputGH
-              CCTK_RegisterIOMethodOutputVarAs
               CCTK_RegisterIOMethodTimeToOutput
               CCTK_RegisterIOMethodTriggerOutput
 
@@ -119,7 +119,6 @@ static void *IOBasic_SetupGH (tFleshConfig *config,
     /* Register the IOBasic routines as output methods  */
     i = CCTK_RegisterIOMethod ("Scalar");
     CCTK_RegisterIOMethodOutputGH (i, IOBasic_ScalarOutputGH);
-    CCTK_RegisterIOMethodOutputVarAs (i, IOBasic_ScalarOutputVarAs);
     CCTK_RegisterIOMethodTimeToOutput (i, IOBasic_TimeForScalarOutput);
     CCTK_RegisterIOMethodTriggerOutput (i, IOBasic_TriggerScalarOutput);
 
@@ -128,8 +127,7 @@ static void *IOBasic_SetupGH (tFleshConfig *config,
     CCTK_RegisterIOMethodTimeToOutput (i, IOBasic_TimeForInfoOutput);
     CCTK_RegisterIOMethodTriggerOutput (i, IOBasic_TriggerInfoOutput);
 
-    if (CCTK_Equals (newverbose, "standard") ||
-        CCTK_Equals( newverbose, "full"))
+    if (! CCTK_Equals (newverbose, "none"))
     {
       CCTK_INFO ("I/O Method 'Scalar' registered");
       CCTK_INFO ("Scalar: Output of scalar quantities (grid scalars, "
@@ -142,51 +140,61 @@ static void *IOBasic_SetupGH (tFleshConfig *config,
     i = CCTK_NumVars ();
 
     newGH->info_reductions = (iobasic_reductionlist_t *)
-                             calloc (i, sizeof (iobasic_reductionlist_t));
-    newGH->do_outScalar   = (char *) malloc (i * sizeof (char));
-    newGH->outInfo_last   = (int *)  malloc (i * sizeof (int));
-    newGH->outScalar_last = (int *)  malloc (i * sizeof (int));
+                             calloc (2 * i, sizeof (iobasic_reductionlist_t));
+    newGH->scalar_reductions = newGH->info_reductions + i;
+    newGH->outInfo_last   = (int *)  malloc (2 * i * sizeof (int));
+    newGH->outScalar_last = newGH->outInfo_last + i;
 
-    memset (newGH->outInfo_last,   -1, i * sizeof (int));
-    memset (newGH->outScalar_last, -1, i * sizeof (int));
+    memset (newGH->outInfo_last, -1, 2 * i * sizeof (int));
 
     newGH->filenameListScalar = NULL;
 
-    /* Check whether "IOBasic::outdirScalar" was set.
+    /* Check whether "IOBasic::outdir" was set.
        If so take this dir otherwise default to "IO::outdir" */
-    if (CCTK_ParameterQueryTimesSet ("outdirScalar", CCTK_THORNSTRING) <= 0)
+    if (CCTK_ParameterQueryTimesSet ("outdir", CCTK_THORNSTRING) > 0 ||
+        CCTK_ParameterQueryTimesSet ("outdirScalar", CCTK_THORNSTRING) > 0)
     {
-      outdirScalar = outdir;
+      if (CCTK_ParameterQueryTimesSet ("outdir", CCTK_THORNSTRING) <= 0)
+      {
+        CCTK_WARN (1, "Parameter 'IOBasic::outdirScalar is depricated in "
+                      "BETA12, please use 'IOBasic::outdir' instead");
+        outdir = outdirScalar;
+      }
+    }
+    else
+    {
+      outdir = *(const char **)
+              CCTK_ParameterGet ("outdir", CCTK_ImplementationThorn ("IO"), &i);
     }
+
     /* skip the directory pathname if output goes into current directory */
-    if (strcmp (outdirScalar, "."))
+    if (strcmp (outdir, "."))
     {
-      i = strlen (outdirScalar);
-      newGH->outdirScalar = (char *) malloc (i + 2);
-      strcpy (newGH->outdirScalar, outdirScalar);
-      newGH->outdirScalar[i] = '/';
-      newGH->outdirScalar[i+1] = 0;
+      i = strlen (outdir);
+      newGH->outdir = (char *) malloc (i + 2);
+      strcpy (newGH->outdir, outdir);
+      newGH->outdir[i] = '/';
+      newGH->outdir[i+1] = 0;
     }
     else
     {
-      newGH->outdirScalar = "";
+      newGH->outdir = "";
     }
 
     /* create the output dir */
-    if (*newGH->outdirScalar && CCTK_MyProc (GH) == 0)
+    if (*newGH->outdir && CCTK_MyProc (GH) == 0)
     {
-      i = IOUtil_CreateDirectory (GH, newGH->outdirScalar, 0, 0);
+      i = IOUtil_CreateDirectory (GH, newGH->outdir, 0, 0);
       if (i < 0)
       {
         CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
                     "IOBasic_SetupGH: Couldn't create Scalar output directory "
-                    "'%s'", newGH->outdirScalar);
+                    "'%s'", newGH->outdir);
       }
       else if (i >= 0 && CCTK_Equals (newverbose, "full"))
       {
-	CCTK_VInfo (CCTK_THORNSTRING,
-		    "Scalar: Output to directory '%s'",
-		    newGH->outdirScalar);
+        CCTK_VInfo (CCTK_THORNSTRING, "Scalar: Output to directory '%s'",
+                    newGH->outdir);
       }
 
     }
@@ -194,3 +202,170 @@ static void *IOBasic_SetupGH (tFleshConfig *config,
 
   return (newGH);
 }
+
+
+ /*@@
+   @routine    IOBasic_AssignReductionList
+   @date       Tue 31 Jul 2001
+   @author     Thomas Radke
+   @desc
+               Callback routine called by CCTK_TraverseString() to set the
+               reduction list for a given variable.
+               For CCTK_GF and CCTK_ARRAY variables, it builds a chained list
+               of reduction operators according to the settings of 'optstring'
+               or the 'IOBasic::out{Info|Scalar}_reductions' parameter.
+   @enddesc
+   @calls      CCTK_GroupTypeFromVarI
+               CCTK_ReductionHandle
+
+   @var        vindex
+   @vdesc      index of the variable to set info output
+   @vtype      int
+   @vio        in
+   @endvar
+   @var        optstring
+   @vdesc      option string for this variable
+   @vtype      const char *
+   @vio        in
+   @endvar
+   @var        arg
+   @vdesc      user-supplied argument to callback routine
+   @vtype      void *
+   @vio        in
+   @endvar
+@@*/
+void IOBasic_AssignReductionList (int vindex, const char *optstring, void *arg)
+{
+  const char *string_start, *string_end;
+  char *reduction_op, *reduction_op_list;
+  int reduction_handle;
+  iobasic_reductionlist_t *list;
+  iobasic_reduction_t **new_reduction;
+  const iobasic_parseinfo_t *info;
+
+
+  info = (const iobasic_parseinfo_t *) arg;
+  list = info->reduction_list + vindex;
+
+  if (CCTK_GroupTypeFromVarI (vindex) == CCTK_SCALAR)
+  {
+    if (optstring)
+    {
+      CCTK_VWarn (5, __LINE__, __FILE__, CCTK_THORNSTRING,
+                  "option list '%s' for variable '%s' ignored",
+                  optstring, CCTK_VarName (vindex));
+    }
+
+    list->reductions = (iobasic_reduction_t *)
+                       malloc (sizeof (iobasic_reduction_t));
+    if (strncmp (CCTK_VarTypeName (CCTK_VarTypeI (vindex)),
+                 "CCTK_VARIABLE_COMPLEX", 21))
+    {
+      list->num_reductions = 1;
+      list->reductions->name = strdup ("scalar value");
+      list->reductions->next = NULL;
+    }
+    else
+    {
+      list->num_reductions = 2;
+      list->reductions->name = strdup ("real part");
+      list->reductions->next = (iobasic_reduction_t *)
+                               malloc (sizeof (iobasic_reduction_t));
+      list->reductions->next->name = strdup ("imag part");
+      list->reductions->next->next = NULL;
+    }
+
+    return;
+  }
+
+  /* initialize to empty list */
+  list->num_reductions = 0;
+  list->reductions = NULL;
+
+  if (optstring)
+  {
+    if (strncmp (optstring, "reductions=<", 12) == 0 &&
+        optstring[strlen (optstring) - 1] == '>')
+    {
+      reduction_op_list = strdup (optstring + 12);
+      reduction_op_list[strlen (reduction_op_list) - 1] = 0;
+    }
+    else
+    {
+      CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
+                  "IOBasic_AssignReductionList: invalid syntax for option list "
+                  "'%s'", optstring);
+      return;
+    }
+  }
+  else
+  {
+    reduction_op_list = strdup (info->reductions_string);
+  }
+
+  /* now loop over all reduction operators */
+  string_start = reduction_op_list;
+  reduction_op = (char *) malloc (strlen (string_start) + 1);
+  while (string_start && *string_start)
+  {
+    /* skip leading spaces */
+    while (isspace ((int) *string_start))
+    {
+      string_start++;
+    }
+    if (! *string_start)
+    {
+      break;
+    }
+
+    /* advance to end of the operator string */
+    string_end = string_start + 1;
+    while (*string_end && ! isspace ((int) *string_end))
+    {
+      string_end++;
+    }
+
+    /* copy the operator string */
+    strncpy (reduction_op, string_start, string_end - string_start);
+    reduction_op[string_end - string_start] = 0;
+    string_start = string_end;
+
+    /* get the reduction handle from the reduction operator */
+    reduction_handle = CCTK_ReductionHandle (reduction_op);
+    if (reduction_handle < 0)
+    {
+      CCTK_VWarn (5, __LINE__, __FILE__, CCTK_THORNSTRING,
+                  "IOBasic_AssignReductionList: Invalid reduction operator "
+                  "'%s'", reduction_op);
+      continue;
+    }
+
+    /* add new reduction to end of list */
+    new_reduction = &list->reductions;
+    while (*new_reduction)
+    {
+      if (strcmp ((*new_reduction)->name, reduction_op) == 0)
+      {
+        new_reduction = NULL;
+        break;
+      }
+      new_reduction = &((*new_reduction)->next);
+    }
+    if (new_reduction == NULL)
+    {
+      CCTK_VWarn (3, __LINE__, __FILE__, CCTK_THORNSTRING,
+                  "IOBasic_AssignReductionList: Duplicate reduction operator "
+                  "'%s' will be ignored", reduction_op);
+      continue;
+    }
+
+    *new_reduction = (iobasic_reduction_t *) malloc (sizeof (**new_reduction));
+    (*new_reduction)->handle = reduction_handle;
+    (*new_reduction)->name   = strdup (reduction_op);
+    (*new_reduction)->next   = NULL;
+    list->num_reductions++;
+  }
+
+  free (reduction_op_list);
+  free (reduction_op);
+}
diff --git a/src/WriteScalar.c b/src/WriteScalar.c
index 413463c..12083de 100644
--- a/src/WriteScalar.c
+++ b/src/WriteScalar.c
@@ -24,6 +24,8 @@ static const char *rcsid = "$Header$";
 CCTK_FILEVERSION(CactusBase_IOBasic_WriteScalar_c)
 
 
+static int IOBasic_WriteScalarGS (const cGH *GH, int vindex, const char *alias);
+static int IOBasic_WriteScalarGA (const cGH *GH, int vindex, const char *alias);
 static FILE *OpenScalarFile (const cGH *GH,
                              int vindex,
                              const char *filename,
@@ -32,6 +34,75 @@ static FILE *OpenScalarFile (const cGH *GH,
                              const char *aliasname);
 
  /*@@
+   @routine   IOBasic_WriteScalar
+   @date      Mon Jun 19 2000
+   @author    Thomas Radke
+   @desc
+              Write a scalar value of a CCTK variable into an ASCII file
+              suitable for postprocessing by either gluplot or xgraph.
+              This routine just calls the appropriate output routine
+              according the the variable type.
+   @enddesc
+
+   @calls     CCTK_QueryGroupStorageI
+              CCTK_GroupIndexFromVarI
+              CCTK_GroupTypeFromVarI
+              IOBasic_WriteScalarGS
+              IOBasic_WriteScalarGA
+
+   @var       GH
+   @vdesc     Pointer to CCTK grid hierarchy
+   @vtype     const cGH *
+   @vio       in
+   @endvar
+   @var       vindex
+   @vdesc     CCTK index of the variable to output
+   @vtype     int
+   @vio       in
+   @endvar
+   @var       alias
+   @vdesc     alias name to use for building the output filename
+   @vtype     const char *
+   @vio       in
+   @endvar
+
+   @returntype int
+   @returndesc
+               return code of either @seeroutine IOBasic_WriteScalarGS or
+               @seeroutine IOBasic_WriteScalarGA, or<BR>
+               -1 if variable has no storage assigned
+   @endreturndesc
+@@*/
+int IOBasic_WriteScalar (const cGH *GH, int vindex, const char *alias)
+{
+  int retval;
+  char *fullname;
+
+
+  /* check if variable has storage assigned */
+  if (! CCTK_QueryGroupStorageI (GH, CCTK_GroupIndexFromVarI (vindex)))
+  {
+    fullname = CCTK_FullName (vindex);
+    CCTK_VWarn (2, __LINE__, __FILE__, CCTK_THORNSTRING,
+                "IOBasic_WriteScalar: No scalar output for '%s' (no storage)", 
+                fullname);
+    free (fullname);
+    retval = -1;
+  }
+  else if (CCTK_GroupTypeFromVarI (vindex) == CCTK_SCALAR)
+  { 
+    retval = IOBasic_WriteScalarGS (GH, vindex, alias);
+  }
+  else
+  { 
+    retval = IOBasic_WriteScalarGA (GH, vindex, alias);
+  }
+
+  return (retval);
+}
+
+
+ /*@@
    @routine   IOBasic_WriteScalarGA
    @date      Mon Jun 19 2000
    @author    Thomas Radke
@@ -41,8 +112,7 @@ static FILE *OpenScalarFile (const cGH *GH,
               suitable for postprocessing by either gluplot or xgraph.
    @enddesc
 
-   @calls     CCTK_QueryGroupStorageI
-              CCTK_Reduce
+   @calls     CCTK_Reduce
               CCTK_ReductionHandle
               IOUtil_RestartFromRecovery
               IOUtil_AdvertiseFile
@@ -65,24 +135,17 @@ static FILE *OpenScalarFile (const cGH *GH,
 
    @returntype int
    @returndesc
-                0 for success, or<BR>
-               -1 if variable has no storage assigned
+                0 for success
    @endreturndesc
 @@*/
-int IOBasic_WriteScalarGA (const cGH *GH, int vindex, const char *alias)
+static int IOBasic_WriteScalarGA (const cGH *GH, int vindex, const char *alias)
 {
-  int ierr;
-  int reduction_handle;
   iobasicGH *myGH;
   FILE *file;
   char *filename;
-  char *reduction_op;
-  char *string_start;
-  char *string_end;
   char format_str[15];
   const char *file_extension;
-  char *fullname;
-  CCTK_REAL reduction_value;
+  iobasic_reduction_t *reduction;
   union
   {
     char *non_const_ptr;
@@ -102,17 +165,6 @@ int IOBasic_WriteScalarGA (const cGH *GH, int vindex, const char *alias)
   reductions.const_ptr = outScalar_reductions;
   GH_fake_const.const_ptr = GH;
 
-  /* first, check if variable has storage assigned */
-  if (! CCTK_QueryGroupStorageI (GH, CCTK_GroupIndexFromVarI (vindex)))
-  {
-    fullname = CCTK_FullName (vindex);
-    CCTK_VWarn (2, __LINE__, __FILE__, CCTK_THORNSTRING,
-                "IOBasic_WriteScalarGA: No scalar output for '%s' (no storage)", 
-                fullname);
-    free (fullname);
-    return (-1);
-  }
-
   /* set output format */
   sprintf (format_str, "%%%s\t%%%s\n", out_format, out_format);
 
@@ -121,100 +173,71 @@ int IOBasic_WriteScalarGA (const cGH *GH, int vindex, const char *alias)
 
   /* get the GH extension handle for IOBasic */
   myGH = (iobasicGH *) CCTK_GHExtension (GH, "IOBasic");
-
-  /* allocate string for the reduction operator */
-  reduction_op = (char *) malloc (strlen (reductions.const_ptr) + 1);
+  reduction = myGH->scalar_reductions[vindex].reductions;
 
   /* now loop over all reduction operators */
-  string_start = reductions.non_const_ptr;
-  while (string_start && *string_start)
+  while (reduction)
   {
-    /* skip leading spaces */
-    while (isspace ((int) *string_start))
-    {
-      string_start++;
-    }
-    if (! *string_start)
-    {
-      break;
-    }
-
-    /* advance to end of the operator string */
-    string_end = string_start + 1;
-    while (*string_end && ! isspace ((int) *string_end))
-    {
-      string_end++;
-    }
-
-    /* copy the operator string */
-    strncpy (reduction_op, string_start, string_end - string_start);
-    reduction_op[string_end - string_start] = 0;
-    string_start = string_end;
-
-    /* get the reduction handle from the reduction operator */
-    reduction_handle = CCTK_ReductionHandle (reduction_op);
-    if (reduction_handle < 0) 
+    /* do the reduction (all processors) */
+    reduction->is_valid = CCTK_Reduce (GH_fake_const.non_const_ptr, 0,
+                                       reduction->handle, 1,
+                                       CCTK_VARIABLE_REAL,
+                                       &reduction->value, 1, vindex) == 0;
+    if (! reduction->is_valid)
     {
       CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
-                  "IOBasic_WriteScalarGA: Invalid reduction operator '%s'", 
-                  reduction_op);
-      continue;
+                  "IOBasic_WriteInfo: Internal error in reduction '%s'",
+                  reduction->name);
     }
-
-    /* do the reduction (all processors) */
-    ierr = CCTK_Reduce (GH_fake_const.non_const_ptr, 0, reduction_handle, 1,
-                        CCTK_VARIABLE_REAL, &reduction_value, 1, vindex);
-
-    /* dump the reduction value to file by processor 0 */
-    if (ierr == 0 && CCTK_MyProc (GH) == 0)
+    else if (CCTK_MyProc (GH) == 0)
     {
-
+      /* dump the reduction value to file by processor 0 */
       if (new_filename_scheme)
       {
         /* allocate filename string buffer and build the filename */
-        filename = (char *) malloc (strlen (myGH->outdirScalar) +
-                                    strlen (alias) + strlen (reduction_op) +
+        filename = (char *) malloc (strlen (myGH->outdir) +
+                                    strlen (alias) + strlen (reduction->name) +
                                     strlen (file_extension) + 2);
-        sprintf (filename, "%s%s_%s%s", myGH->outdirScalar, alias,
-                                        reduction_op, file_extension);
+        sprintf (filename, "%s%s_%s%s", myGH->outdir, alias,
+                                        reduction->name, file_extension);
       }
       else
       {
         /* FIXME: this check can go if we switch to the new filename scheme */
-        if (strcmp (reduction_op, "minimum") == 0)
+        if (strcmp (reduction->name, "minimum") == 0)
         {
           file_extension = "min";
         }
-        else if (strcmp (reduction_op, "maximum") == 0)
+        else if (strcmp (reduction->name, "maximum") == 0)
         {
           file_extension = "max";
         }
-        else if (strcmp (reduction_op, "norm1") == 0)
+        else if (strcmp (reduction->name, "norm1") == 0)
         {
           file_extension = "nm1";
         }
-        else if (strcmp (reduction_op, "norm2") == 0)
+        else if (strcmp (reduction->name, "norm2") == 0)
         {
           file_extension = "nm2";
         }
         else
         {
-          file_extension = reduction_op;
+          file_extension = reduction->name;
         }
 
         /* allocate filename string buffer and build the filename */
-        filename = (char *) malloc (strlen (myGH->outdirScalar) +
+        filename = (char *) malloc (strlen (myGH->outdir) +
                                     strlen (alias) + strlen (file_extension)+5);
-        sprintf (filename, "%s%s_%s.tl", myGH->outdirScalar, alias,
+        sprintf (filename, "%s%s_%s.tl", myGH->outdir, alias,
                  file_extension);
       }
 
-      file = OpenScalarFile (GH, vindex, filename, reduction_op,
+      file = OpenScalarFile (GH, vindex, filename, reduction->name,
                              "Reduction on Grid Arrays", alias);
       if (file)
       {
         /* write the data and close the file */
-        fprintf (file, format_str, GH->cctk_time, reduction_value);
+        fprintf (file, format_str, GH->cctk_time, reduction->value);
         fclose (file);
       }
       else
@@ -225,10 +248,9 @@ int IOBasic_WriteScalarGA (const cGH *GH, int vindex, const char *alias)
       }
       free (filename);
     }
-  }
 
-  /* free allocated resources */
-  free (reduction_op);
+    reduction = reduction->next;
+  }
 
   return (0);
 }
@@ -243,8 +265,7 @@ int IOBasic_WriteScalarGA (const cGH *GH, int vindex, const char *alias)
               suitable for postprocessing by either gluplot or xgraph.
    @enddesc
 
-   @calls     CCTK_QueryGroupStorageI
-              CCTK_Reduce
+   @calls     CCTK_Reduce
               CCTK_ReductionHandle
               IOUtil_RestartFromRecovery
               IOUtil_AdvertiseFile
@@ -267,19 +288,18 @@ int IOBasic_WriteScalarGA (const cGH *GH, int vindex, const char *alias)
 
    @returntype int
    @returndesc
-                0 for success, or<BR>
-               -1 if variable has no storage assigned
+                0 for success
    @endreturndesc
 @@*/
-int IOBasic_WriteScalarGS (const cGH *GH, int vindex, const char *alias)
+static int IOBasic_WriteScalarGS (const cGH *GH, int vindex, const char *alias)
 {
-  DECLARE_CCTK_PARAMETERS
   FILE *file;
   void *data;
   iobasicGH *myGH;
-  char *fullname, *filename;
+  char *filename;
   const char *file_extension;
   char format_str_real[15], format_str_int[15];
+  DECLARE_CCTK_PARAMETERS
 
 
   /* output is done by processor 0 only */
@@ -288,17 +308,6 @@ int IOBasic_WriteScalarGS (const cGH *GH, int vindex, const char *alias)
     return (0);
   }
 
-  /* first, check if variable has storage assigned */
-  if (! CCTK_QueryGroupStorageI (GH, CCTK_GroupIndexFromVarI (vindex)))
-  {
-    fullname = CCTK_FullName (vindex);
-    CCTK_VWarn (2, __LINE__, __FILE__, CCTK_THORNSTRING,
-                "IOBasic_WriteScalarGS: No scalar output for '%s' (no storage)",
-                fullname);
-    free (fullname);
-    return (-1);
-  }
-
   /* set the output format string for the desired notation */
   sprintf (format_str_real, "%%%s\t%%%s\n", out_format, out_format);
   sprintf (format_str_int,  "%%%s\t%%d\n", out_format);
@@ -317,9 +326,9 @@ int IOBasic_WriteScalarGS (const cGH *GH, int vindex, const char *alias)
   }
 
   /* build the output filename */
-  filename = (char *) malloc (strlen (myGH->outdirScalar) + strlen (alias) +
+  filename = (char *) malloc (strlen (myGH->outdir) + strlen (alias) +
                               strlen (file_extension) + 1);
-  sprintf (filename, "%s%s%s", myGH->outdirScalar, alias, file_extension);
+  sprintf (filename, "%s%s%s", myGH->outdir, alias, file_extension);
 
   /* create/reopen the file */
   file = OpenScalarFile (GH, vindex, filename, "tl", "Scalar value", alias);
diff --git a/src/iobasicGH.h b/src/iobasicGH.h
index c75b70e..e957a00 100644
--- a/src/iobasicGH.h
+++ b/src/iobasicGH.h
@@ -26,25 +26,26 @@ typedef struct IOBASIC_REDUCTIONLIST
   iobasic_reduction_t *reductions;
 } iobasic_reductionlist_t;
 
+typedef struct IOBASIC_PARSEINFO
+{
+  const char *reductions_string;
+  iobasic_reductionlist_t *reduction_list;
+} iobasic_parseinfo_t;
+
 typedef struct IOBASIC_GH
 {
   /* how often to output */
-  int  outScalar_every;
-  int  outInfo_every;
+  int  outScalar_every, outInfo_every;
   char info_reductions_changed;
 
-  /* flags indicating output for variable i */
-  char   *do_outScalar;
-
   /* directory in which to place scalar output */
-  char  *outdirScalar;
+  char *outdir;
 
   /* The last iteration output */
-  int   *outInfo_last;
-  int   *outScalar_last;
+  int *outInfo_last, *outScalar_last;
 
-  /* The reduction lists for info output for all variables */
-  iobasic_reductionlist_t *info_reductions;
+  /* The reduction lists for info and scalar output for all variables */
+  iobasic_reductionlist_t *info_reductions, *scalar_reductions;
 
   /* database for names of output files that were already created */
   pNamedData *filenameListScalar;
@@ -59,9 +60,8 @@ int IOBasic_TimeForInfoOutput (const cGH *GH, int vindex);
 int IOBasic_ScalarOutputGH (const cGH *GH);
 int IOBasic_TriggerScalarOutput (const cGH *GH, int vindex);
 int IOBasic_TimeForScalarOutput (const cGH *GH, int vindex);
-int IOBasic_ScalarOutputVarAs (const cGH *GH, const char *vname, const char *alias);
 
 /* other function prototypes */
+void IOBasic_AssignReductionList (int vindex, const char *optstring, void *arg);
 int IOBasic_WriteInfo (const cGH *GH, int vindex);
-int IOBasic_WriteScalarGS (const cGH *GH, int vindex, const char *alias);
-int IOBasic_WriteScalarGA (const cGH *GH, int vindex, const char *alias);
+int IOBasic_WriteScalar (const cGH *GH, int vindex, const char *alias);