+/* Jalview - A Sequence Alignment Editor and Viewer (Version 2.5)
+ * Copyright (C) 2010 J Procter, AM Waterhouse, G Barton, M Clamp, S Searle
+ *
+ * This file is part of Jalview.
+ *
+ * Jalview is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * Jalview is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Jalview. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* Author: Lauren Michelle Lui
+ * Methods are based on RALEE methods http://personalpages.manchester.ac.uk/staff/sam.griffiths-jones/software/ralee/
+ * */
+
+package jalview.analysis;
+
+import java.util.Hashtable;
+import java.util.Vector;
+
+import jalview.datamodel.SequenceFeature;
+
+public class Rna
+{
+ /**
+ * Based off of RALEE code ralee-get-base-pairs. Keeps track of open bracket
+ * positions in "stack" vector. When a close bracket is reached, pair this
+ * with the last element in the "stack" vector and store in "pairs" vector.
+ * Remove last element in the "stack" vector. Continue in this manner until
+ * the whole string is processed.
+ *
+ * @param line
+ * Secondary structure line of an RNA Stockholm file
+ * @return Array of SequenceFeature; type = RNA helix, begin is open base
+ * pair, end is close base pair
+ */
+ public static SequenceFeature[] GetBasePairs(String line)
+ {
+
+ Vector stack = new Vector();
+ Vector pairs = new Vector();
+
+ int i = 0;
+ while (i < line.length())
+ {
+ char base = line.charAt(i);
+
+ if ((base == '<') || (base == '(') || (base == '{') || (base == '['))
+ {
+ stack.addElement(i);
+ }
+ else if ((base == '>') || (base == ')') || (base == '}')
+ || (base == ']'))
+ {
+
+ Object temp = stack.lastElement();
+ stack.remove(stack.size() - 1);
+ pairs.addElement(temp);
+ pairs.addElement(i);
+ }
+
+ i++;
+ }
+
+ int numpairs = pairs.size() / 2;
+ SequenceFeature[] outPairs = new SequenceFeature[numpairs];
+
+ // Convert pairs to array
+ for (int p = 0; p < pairs.size(); p += 2)
+ {
+ int begin = Integer.parseInt(pairs.elementAt(p).toString());
+ int end = Integer.parseInt(pairs.elementAt(p + 1).toString());
+
+ outPairs[p / 2] = new SequenceFeature("RNA helix", "", "", begin,
+ end, "");
+ }
+
+ return outPairs;
+ }
+
+ /**
+ * Figures out which helix each position belongs to and stores the helix
+ * number in the 'featureGroup' member of a SequenceFeature Based off of RALEE
+ * code ralee-helix-map.
+ *
+ * @param pairs
+ * Array of SequenceFeature (output from Rna.GetBasePairs)
+ */
+ public static void HelixMap(SequenceFeature[] pairs)
+ {
+
+ int helix = 0; // Number of helices/current helix
+ int lastopen = 0; // Position of last open bracket reviewed
+ int lastclose = 9999999; // Position of last close bracket reviewed
+ int i = pairs.length; // Number of pairs
+
+ int open; // Position of an open bracket under review
+ int close; // Position of a close bracket under review
+ int j; // Counter
+
+ Hashtable helices = new Hashtable(); // Keep track of helix number for each
+ // position
+
+ // Go through each base pair and assign positions a helix
+ for (i = 0; i < pairs.length; i++)
+ {
+
+ open = pairs[i].getBegin();
+ close = pairs[i].getEnd();
+
+ // System.out.println("open " + open + " close " + close);
+ // System.out.println("lastclose " + lastclose + " lastopen " + lastopen);
+
+ // we're moving from right to left based on closing pair
+ /*
+ * catch things like <<..>>..<<..>> |
+ */
+ if (open > lastclose)
+ {
+ helix++;
+ }
+
+ /*
+ * catch things like <<..<<..>>..<<..>>>> |
+ */
+ j = pairs.length - 1;
+ while (j >= 0)
+ {
+ int popen = pairs[j].getBegin();
+
+ // System.out.println("j " + j + " popen " + popen + " lastopen "
+ // +lastopen + " open " + open);
+ if ((popen < lastopen) && (popen > open))
+ {
+ if (helices.containsValue(popen)
+ && (((Integer) helices.get(popen)) == helix))
+ {
+ continue;
+ }
+ else
+ {
+ helix++;
+ break;
+ }
+ }
+
+ j -= 1;
+ }
+
+ // Put positions and helix information into the hashtable
+ helices.put(open, helix);
+ helices.put(close, helix);
+
+ // Record helix as featuregroup
+ pairs[i].setFeatureGroup(Integer.toString(helix));
+ pairs[i].setFeatureGroup(Integer.toString(helix));
+
+ lastopen = open;
+ lastclose = close;
+
+ }
+ }
+}