diff --git a/src/FLD/pair_brownian_poly.cpp b/src/FLD/pair_brownian_poly.cpp
index 43a0d80628..906c62cc6d 100644
--- a/src/FLD/pair_brownian_poly.cpp
+++ b/src/FLD/pair_brownian_poly.cpp
@@ -84,8 +84,7 @@ void PairBrownianPoly::compute(int eflag, int vflag)
   double xl[3],a_sq,a_sh,a_pu,Fbmag;
   double p1[3],p2[3],p3[3];
 
-
-  // This section of code adjusts R0/RT0/RS0 if necessary due to changes
+  // this section of code adjusts R0/RT0/RS0 if necessary due to changes
   // in the volume fraction as a result of fix deform or moving walls
 
   double dims[3], wallcoord;
diff --git a/src/RIGID/fix_rigid_small.cpp b/src/RIGID/fix_rigid_small.cpp
index 92fd759f47..7c2aad2e85 100644
--- a/src/RIGID/fix_rigid_small.cpp
+++ b/src/RIGID/fix_rigid_small.cpp
@@ -65,8 +65,6 @@ FixRigidSmall::FixRigidSmall(LAMMPS *lmp, int narg, char **arg) :
 {
   int i,ibody;
 
-  scalar_flag = 1;
-  extscalar = 0;
   time_integrate = 1;
   rigid_flag = 1;
   virial_flag = 1;
diff --git a/src/input.cpp b/src/input.cpp
index dc8df035f4..51772ffec2 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -383,7 +383,8 @@ void Input::substitute(char *&str, char *&str2, int &max, int &max2, int flag)
   //   else $x becomes x followed by NULL
   // beyond = points to text following variable
 
-  int n;
+  int i,n,paren_count;
+  char immediate[256];
   char *var,*value,*beyond;
   char quote = '\0';
   char *ptr = str;
@@ -394,23 +395,56 @@ void Input::substitute(char *&str, char *&str2, int &max, int &max2, int flag)
   char *ptr2 = str2;
 
   while (*ptr) {
-    // expand variable and append to str2
+    // variable substitution
 
     if (*ptr == '$' && !quote) {
+
+      // value = ptr to expanded variable
+      // variable name between curly braces, e.g. ${a}
+
       if (*(ptr+1) == '{') {
         var = ptr+2;
-        int i = 0;
+        i = 0;
+
         while (var[i] != '\0' && var[i] != '}') i++;
+
         if (var[i] == '\0') error->one(FLERR,"Invalid variable name");
         var[i] = '\0';
         beyond = ptr + strlen(var) + 3;
+        value = variable->retrieve(var);
+
+      // immediate variable between parenthesis, e.g. $(1/2)
+
+      } else if (*(ptr+1) == '(') {
+        var = ptr+2;
+        paren_count = 0;
+        i = 0;
+
+        while (var[i] != '\0' && !(var[i] == ')' && paren_count == 0)) {
+          switch (var[i]) {
+            case '(': paren_count++; break;
+            case ')': paren_count--; break;
+            default: ;
+          }
+          i++;
+        }
+
+        if (var[i] == '\0') error->one(FLERR,"Invalid immediate variable");
+        var[i] = '\0';
+        beyond = ptr + strlen(var) + 3;
+        sprintf(immediate,"%.20g",variable->compute_equal(var));
+        value = immediate;
+
+      // single character variable name, e.g. $a
+
       } else {
         var = ptr;
         var[0] = var[1];
         var[1] = '\0';
         beyond = ptr + 2;
+        value = variable->retrieve(var);
       }
-      value = variable->retrieve(var);
+
       if (value == NULL) error->one(FLERR,"Substitution for illegal variable");
 
       // check if storage in str2 needs to be expanded
@@ -428,8 +462,10 @@ void Input::substitute(char *&str, char *&str2, int &max, int &max2, int flag)
         if (echo_screen && screen) fprintf(screen,"%s%s\n",str2,beyond);
         if (echo_log && logfile) fprintf(logfile,"%s%s\n",str2,beyond);
       }
+
       continue;
     }
+
     if (*ptr == quote) quote = '\0';
     else if (*ptr == '"' || *ptr == '\'') quote = *ptr;
 
diff --git a/src/variable.cpp b/src/variable.cpp
index d588ba959e..c75964b911 100644
--- a/src/variable.cpp
+++ b/src/variable.cpp
@@ -526,6 +526,16 @@ double Variable::compute_equal(int ivar)
   return value;
 }
 
+/* ----------------------------------------------------------------------
+   return result of immediate equal-style variable evaluation
+   called from Input::substitute()
+------------------------------------------------------------------------- */
+
+double Variable::compute_equal(char *str)
+{
+  return evaluate(str,NULL);
+}
+
 /* ----------------------------------------------------------------------
    compute result of atom-style variable evaluation
    only computed for atoms in igroup, else result is 0.0
diff --git a/src/variable.h b/src/variable.h
index 98bdb08dad..1d7ff83952 100644
--- a/src/variable.h
+++ b/src/variable.h
@@ -31,6 +31,7 @@ class Variable : protected Pointers {
   int atomstyle(int);
   char *retrieve(char *);
   double compute_equal(int);
+  double compute_equal(char *);
   void compute_atom(int, int, double *, int, int);
   int int_between_brackets(char *&);
   double evaluate_boolean(char *);