Index: /trunk/Ohana/src/opihi/cmd.data/read_vectors.c
===================================================================
--- /trunk/Ohana/src/opihi/cmd.data/read_vectors.c	(revision 40011)
+++ /trunk/Ohana/src/opihi/cmd.data/read_vectors.c	(revision 40012)
@@ -115,4 +115,6 @@
   }
   fseeko (f, 0LL, SEEK_SET);
+
+  buffer = NULL;
 
   Nvec = (argc - 1) / 2;
@@ -160,10 +162,19 @@
 
     colstr = argv[2*i+2];
+
+    // numerical columns, e.g., 15, must be base 10 and not have other characters (15x)
+    if (isdigit(colstr[0])) {
+      char *endptr;
+      long colnum_tmp = strtol(colstr, &endptr, 10);
+      if (endptr[0]) {
+	gprint (GP_ERR, "unexpected characters in column number: %s\n", endptr);
+	goto bad_colname;
+      }
+      col[i] = colnum_tmp;
+      continue;
+    }
+
+    // allow 'excel' columns names of the form A-Z, AA-AZ, BA-BZ, .. ZA-ZZ
     for (j = 0; j < strlen (colstr); j++) {
-      if (isdigit(colstr[j])) {
-	col[i] = atof (colstr);
-	continue;
-      }
-      // allow 'excel' columns names of the form A-Z, AA-AZ, BA-BZ, .. ZA-ZZ
       if (strlen(colstr) >= 3) goto bad_colname;
       if (colstr[0] < 'A') goto bad_colname;