Index: trunk/Ohana/src/opihi/cmd.data/concat.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/concat.c	(revision 8131)
+++ trunk/Ohana/src/opihi/cmd.data/concat.c	(revision 20936)
@@ -5,4 +5,5 @@
   int  i, j, Nin;
   double value;
+  opihi_flt *temp;
   Vector *ivec, *ovec;
 
@@ -19,6 +20,11 @@
     Nin = ovec[0].Nelements;
     ovec[0].Nelements++;
-    REALLOCATE (ovec[0].elements, float, ovec[0].Nelements);
-    ovec[0].elements[Nin] = value;
+    if (ovec[0].type == OPIHI_FLT) {
+      REALLOCATE (ovec[0].elements.Flt, opihi_flt, ovec[0].Nelements);
+      ovec[0].elements.Flt[Nin] = value;
+    } else {
+      REALLOCATE (ovec[0].elements.Int, opihi_int, ovec[0].Nelements);
+      ovec[0].elements.Int[Nin] = value;
+    }
     return (TRUE);
   } 
@@ -26,11 +32,39 @@
   if ((ivec = SelectVector (argv[1], OLDVECTOR, TRUE)) == NULL) return (FALSE);
   
-  REALLOCATE (ovec[0].elements, float, ovec[0].Nelements + ivec[0].Nelements);
-  for (j = ovec[0].Nelements, i = 0; i < ivec[0].Nelements; i++, j++) {
-    ovec[0].elements[j] = ivec[0].elements[i];
+  // we have 4 cases: (ivec == flt or int) and (ovec == flt or int)
+  if ((ovec[0].type == OPIHI_FLT) && (ivec[0].type == OPIHI_FLT)) {
+    REALLOCATE (ovec[0].elements.Flt, opihi_flt, ovec[0].Nelements + ivec[0].Nelements);
+    for (j = ovec[0].Nelements, i = 0; i < ivec[0].Nelements; i++, j++) {
+      ovec[0].elements.Flt[j] = ivec[0].elements.Flt[i];
+    }
   }
+  if ((ovec[0].type == OPIHI_FLT) && (ivec[0].type == OPIHI_INT)) {
+    REALLOCATE (ovec[0].elements.Flt, opihi_flt, ovec[0].Nelements + ivec[0].Nelements);
+    for (j = ovec[0].Nelements, i = 0; i < ivec[0].Nelements; i++, j++) {
+      ovec[0].elements.Flt[j] = ivec[0].elements.Int[i];
+    }
+  }
+  if ((ovec[0].type == OPIHI_INT) && (ivec[0].type == OPIHI_INT)) {
+    REALLOCATE (ovec[0].elements.Int, opihi_int, ovec[0].Nelements + ivec[0].Nelements);
+    for (j = ovec[0].Nelements, i = 0; i < ivec[0].Nelements; i++, j++) {
+      ovec[0].elements.Int[j] = ivec[0].elements.Int[i];
+    }
+  }
+
+  // this case forces ovec to be raised to FLT
+  if ((ovec[0].type == OPIHI_INT) && (ivec[0].type == OPIHI_FLT)) {
+    ALLOCATE (temp, opihi_flt, ovec[0].Nelements + ivec[0].Nelements);
+    for (i = 0; i < ovec[0].Nelements; i++) {
+      temp[i] = ovec[0].elements.Int[i];
+    }
+    ovec[0].type = OPIHI_FLT;
+    free (ovec[0].elements.Int);
+    ovec[0].elements.Flt = temp;
+    for (j = ovec[0].Nelements, i = 0; i < ivec[0].Nelements; i++, j++) {
+      ovec[0].elements.Flt[j] = ivec[0].elements.Flt[i];
+    }
+  }
+
   ovec[0].Nelements += ivec[0].Nelements;
-  
   return (TRUE);
-    
 }