+ * get the 'initial' position of mpos in To
+ * @param mpos position in from
+ * @return position of first word in to reference frame
+ */
+public int getToPosition(int mpos)
+{
+ int[] mp = shiftTo(mpos);
+ if (mp!=null)
+ {
+ return mp[0];
+ }
+ return mpos;
+}
+/**
+ * get range of positions in To frame for the mpos word in From
+ * @param mpos position in From
+ * @return null or int[] first position in To for mpos, last position in to for Mpos
+ */
+public int[] getToWord(int mpos) {
+ int[] mp=shiftTo(mpos);
+ if (mp!=null) {
+ return new int[] {mp[0], mp[0]+mp[2]*(getFromRatio()-1)};
+ }
+ return null;
+}
+/**
+ * get From position in the associated
+ * reference frame for position pos in the
+ * associated sequence.
+ * @param pos
+ * @return
+ */
+public int getMappedPosition(int pos) {
+ int[] mp = shiftFrom(pos);
+ if (mp!=null)
+ {
+ return mp[0];
+ }
+ return pos;
+}
+public int[] getMappedWord(int pos) {
+ int[] mp = shiftFrom(pos);
+ if (mp!=null)
+ {
+ return new int[] { mp[0], mp[0]+mp[2]*(getToRatio()-1)};
+ }
+ return null;
+}
+
+ /**