private static Node readNode(TrieReader reader, int depth, int maxDepth) throws IOException { if (depth > maxDepth) { skipNode(reader); return null; } long count = reader.readCount(); int depthPlus1 = depth + 1; long sym1 = reader.readSymbol(); // 0+ daughters if (sym1 == -1L) return NodeFactory.createNode(count); // 1+ daughters Node node1 = readNode(reader, depthPlus1, maxDepth); long sym2 = reader.readSymbol(); if (sym2 == -1L) return NodeFactory.createNodeFold((char) sym1, node1, count); Node node2 = readNode(reader, depthPlus1, maxDepth); long sym3 = reader.readSymbol(); if (sym3 == -1L) return NodeFactory.createNode((char) sym1, node1, (char) sym2, node2, count); Node node3 = readNode(reader, depthPlus1, maxDepth); long sym4 = reader.readSymbol(); if (sym4 == -1L) return NodeFactory.createNode( (char) sym1, node1, (char) sym2, node2, (char) sym3, node3, count); Node node4 = readNode(reader, depthPlus1, maxDepth); // 4+ daughters StringBuilder cBuf = new StringBuilder(); cBuf.append((char) sym1); cBuf.append((char) sym2); cBuf.append((char) sym3); cBuf.append((char) sym4); List<Node> nodeList = new ArrayList<Node>(); nodeList.add(node1); nodeList.add(node2); nodeList.add(node3); nodeList.add(node4); long sym; while ((sym = reader.readSymbol()) != -1L) { cBuf.append((char) sym); nodeList.add(readNode(reader, depthPlus1, maxDepth)); } Node[] nodes = nodeList.toArray(EMPTY_NODE_ARRAY); char[] cs = Strings.toCharArray(cBuf); return NodeFactory.createNode(cs, nodes, count); // > 3 daughters }
/** * Removes strings with counts below the specified minimum. Counts for remaining strings are not * affected. Pruning may be interleaved with updating counts in any order. * * @param minCount Minimum count required to retain a substring count. * @throws IllegalArgumentException If the count is less than <code>1</code>. */ public void prune(int minCount) { if (minCount < 1) { String msg = "Prune minimum count must be more than 1." + " Found minCount=" + minCount; throw new IllegalArgumentException(msg); } mRootNode = mRootNode.prune(minCount); if (mRootNode == null) mRootNode = NodeFactory.createNode(0); }
static <E extends ValueNode> E createNode(NodeFactory<E> factory, Object... constants) { ArgumentNode[] argumentNodes = arguments(factory.getExecutionSignature().size()); List<Object> argumentList = new ArrayList<>(); argumentList.addAll(Arrays.asList(constants)); if (ChildrenNode.class.isAssignableFrom(factory.getNodeClass()) || BuiltinNode.class.isAssignableFrom(factory.getNodeClass())) { argumentList.add(argumentNodes); } else { argumentList.addAll(Arrays.asList(argumentNodes)); } return factory.createNode(argumentList.toArray(new Object[argumentList.size()])); }
private Node instantiateNodeForRecipe( RecipeTraceInfo recipeTrace, final ReteNodeRecipe recipe, Collection<ReteNodeRecipe> sameClassRecipes) { if (recipe instanceof IndexerRecipe) { // INSTANTIATE AND HOOK UP // (cannot delay hooking up, because parent determines indexer implementation) ensureParents(recipeTrace); final ReteNodeRecipe parentRecipe = recipeTrace.getParentRecipeTraces().iterator().next().getRecipe(); final Indexer result = nodeFactory.createIndexer( reteContainer, (IndexerRecipe) recipe, asSupplier( (Address<? extends Supplier>) reteContainer.network.getExistingNodeByRecipe(parentRecipe)), recipeTrace); // REMEMBER if (Options.nodeSharingOption != Options.NodeSharingOption.NEVER) { getNodesByRecipe().put(recipe, reteContainer.makeAddress(result)); sameClassRecipes.add(recipe); } return result; } else { // INSTANTIATE Node result = nodeFactory.createNode(reteContainer, recipe, recipeTrace); // REMEMBER if (Options.nodeSharingOption == Options.NodeSharingOption.ALL) { getNodesByRecipe().put(recipe, reteContainer.makeAddress(result)); sameClassRecipes.add(recipe); } // HOOK UP // (recursion-tolerant due to this delayed order of initialization) ensureParents(recipeTrace); if (recipe instanceof InputRecipe) inputConnector.connectInput((InputRecipe) recipe, result); else connectionFactory.connectToParents(recipeTrace, result); return result; } }
/** * A <code>TrieCharSeqCounter</code> stores counts for substrings of strings. When the counter is * constructed, a maximum length is specified, and counts are only stored for strings up to that * length. For instance, an n-gram language model needs only counts for strings up to length n. * * <p>Strings may be added to the counter using {@link #incrementSubstrings(char[],int,int)}, which * increments the counts for all substrings of the specified character slice up to the specified * maximum length substring. The method {@link #incrementPrefixes(char[],int,int)} increments only * the prefixes of the specified string. All substrings are incremented by incrementing prefixes for * each suffix. A substring counter may be pruned using {@link #prune(int)}, which removes all * substrings with count below the specified threshold. * * <p>There are a wide range of reporting methods for trie-based counters. * * <p><i>Implementation Note:</i> The trie counters are a heavily unfolded implementation of a * character-based Patricia (PAT) trie. * * @author Bob Carpenter * @version 3.8 * @since LingPipe2.0 */ public class TrieCharSeqCounter implements CharSeqCounter { Node mRootNode = NodeFactory.createNode(0); final int mMaxLength; /** * Construct a substring counter that stores substrings up to the specified maximum length. * * @param maxLength Maximum length of substrings stored by this counter. * @throws IllegalArgumentException If the maximum length is negative. */ public TrieCharSeqCounter(int maxLength) { if (maxLength < 0) { String msg = "Max length must be >= 0." + " Found length=" + maxLength; throw new IllegalArgumentException(msg); } mMaxLength = maxLength; } // following is CharSeqCounter interface w. inherited comments public long count(char[] cs, int start, int end) { Strings.checkArgsStartEnd(cs, start, end); return mRootNode.count(cs, start, end); } public long extensionCount(char[] cs, int start, int end) { Strings.checkArgsStartEnd(cs, start, end); return mRootNode.contextCount(cs, start, end); } public char[] observedCharacters() { return com.aliasi.util.Arrays.copy(mRootNode.outcomes(new char[] {}, 0, 0)); } public char[] charactersFollowing(char[] cs, int start, int end) { Strings.checkArgsStartEnd(cs, start, end); return com.aliasi.util.Arrays.copy(mRootNode.outcomes(cs, start, end)); } public int numCharactersFollowing(char[] cs, int start, int end) { Strings.checkArgsStartEnd(cs, start, end); return mRootNode.numOutcomes(cs, start, end); } /** * Returns the sum of counts for all non-empty character sequences. * * @return The sum of counts for all non-empty character sequences. */ public long totalSequenceCount() { long sum = 0l; long[][] uniqueTotals = uniqueTotalNGramCount(); for (int i = 0; i < uniqueTotals.length; ++i) sum += uniqueTotals[i][1]; return sum; } /** * Returns the sum of the counts of all character sequences of the specified length. * * @return The sum of the counts of all character sequences of the specified length. */ public long totalSequenceCount(int length) { return mRootNode.totalNGramCount(length); } /** * Returns the number of character sequences with non-zero counts, including the empty (zero * length) character sequence. * * @return Number of character sequences with non-zero counts. */ public long uniqueSequenceCount() { return mRootNode.size(); } /** * Returns the number of character sequences of the specified length with non-zero counts. * * @return The number of character sequences of the specified length with non-zero counts. */ public long uniqueSequenceCount(int nGramOrder) { return mRootNode.uniqueNGramCount(nGramOrder); } /** * Removes strings with counts below the specified minimum. Counts for remaining strings are not * affected. Pruning may be interleaved with updating counts in any order. * * @param minCount Minimum count required to retain a substring count. * @throws IllegalArgumentException If the count is less than <code>1</code>. */ public void prune(int minCount) { if (minCount < 1) { String msg = "Prune minimum count must be more than 1." + " Found minCount=" + minCount; throw new IllegalArgumentException(msg); } mRootNode = mRootNode.prune(minCount); if (mRootNode == null) mRootNode = NodeFactory.createNode(0); } /** * Returns an array of frequency counts for n-grams of the specified n-gram order sorted in * descending frequency order. This form of result is sometimes called a Zipf plot because of the * sorting. * * @param nGramOrder Order of n-gram counted. * @return Array of frequency counts, sorted in decreasing order of rank. */ public int[] nGramFrequencies(int nGramOrder) { List<Long> counts = countsList(nGramOrder); int[] result = new int[counts.size()]; for (int i = 0; i < result.length; ++i) result[i] = counts.get(i).intValue(); java.util.Arrays.sort(result); for (int i = result.length / 2; i >= 0; --i) { int iOpp = result.length - i - 1; int tmp = result[i]; result[i] = result[iOpp]; result[iOpp] = tmp; } return result; } /** * Returns the array of unique and total n-gram counts for each n-gram length. The return array is * indexed in the first position by n-gram length, and in the second position by <code>0</code> * for unique counts and <code>1</code> for total counts. Thus for <code>0<=n<=maxLength() * </code>: * * <blockquote> * * <code> * uniqueTotalNGramCount()[n][0] == uniqueNGramCount(n) * </code> * * </blockquote> * * and * * <blockquote> * * <code> * uniqueTotalNGramCount()[n][1] == totalNGramCount(n) * </code> * * </blockquote> * * If unique and total counts are required for several n-gram depths, this method is much more * efficient than calling all of the individual methods separately. * * @return The array of unique and total n-gram counts for each n-gram length. */ public long[][] uniqueTotalNGramCount() { long[][] result = new long[mMaxLength + 1][2]; mRootNode.addNGramCounts(result, 0); return result; } /** * Returns a counter of occurrences of the highest frequency n-grams of a specified n-gram order. * The actual n-grams are represented as strings in the result; recall that strings are instances * of {@link CharSequence}. * * <p>The maximum number of results returned must be specified, because the entire set of n-grams * is usually too large to return as a counter. * * @param nGramOrder Order of n-gram to count. * @param maxReturn Maximum number of objects returned. */ public ObjectToCounterMap<String> topNGrams(int nGramOrder, int maxReturn) { NBestCounter counter = new NBestCounter(maxReturn, true); mRootNode.topNGrams(counter, new char[nGramOrder], 0, nGramOrder); return counter.toObjectToCounter(); } /** * Returns the count in the training corpus for the specified sequence of characters. The count * returned may have been reduced from the raw counts in training cases by pruning. * * @param cSeq Character sequence. * @return Count of character sequence in model. */ public long count(CharSequence cSeq) { return count(com.aliasi.util.Arrays.toArray(cSeq), 0, cSeq.length()); } /** * Returns the sum of the counts of all character sequences one character longer than the * specified character sequence. * * @param cSeq Character sequence. * @return The sum of the counts of all character sequences one character longer than the * specified character sequence. */ public long extensionCount(CharSequence cSeq) { return mRootNode.contextCount(com.aliasi.util.Arrays.toArray(cSeq), 0, cSeq.length()); } /** * Increments the count of all substrings of the specified character array slice up to the maximum * length specified in the constructor. * * @param cs Underlying character array. * @param start Index of first character in slice. * @param end Index of one past last character in slice. * @throws IndexOutOfBoundsException If the specified start and one plus end point are not in the * bounds of character sequence. */ public void incrementSubstrings(char[] cs, int start, int end) { incrementSubstrings(cs, start, end, 1); } /** * Increments by the specified count all substrings of the specified character array slice up to * the maximum length specified in the constructor. * * @param cs Underlying character array. * @param start Index of first character in slice. * @param end Index of one past last character in slice. * @param count Amount to increment. * @throws IndexOutOfBoundsException If the specified start and one plus end point are not in the * bounds of character sequence. */ public void incrementSubstrings(char[] cs, int start, int end, int count) { Strings.checkArgsStartEnd(cs, start, end); // increment maximal strings and prefixes for (int i = start; i + mMaxLength <= end; ++i) incrementPrefixes(cs, i, i + mMaxLength, count); // increment short final strings and prefixes for (int i = Math.max(start, end - mMaxLength + 1); i < end; ++i) incrementPrefixes(cs, i, end, count); } /** * Increments the count of all substrings of the specified character sequence up to the maximum * length specified in the constructor. * * @param cSeq Character sequence. */ public void incrementSubstrings(CharSequence cSeq) { incrementSubstrings(cSeq, 1); } /** * Increments by the specified count all substrings of the specified character sequence up to the * maximum length specified in the constructor. * * @param cSeq Character sequence. * @param count Amount to increment. */ public void incrementSubstrings(CharSequence cSeq, int count) { incrementSubstrings(com.aliasi.util.Arrays.toArray(cSeq), 0, cSeq.length(), count); } /** * Increments the count of all prefixes of the specified character sequence up to the maximum * length specified in the constructor. * * @param cs Underlying character array. * @param start Index of first character in slice. * @param end Index of one past last character in slice. * @throws IndexOutOfBoundsException If the specified start and one plus end point are not in the * bounds of character sequence. */ public void incrementPrefixes(char[] cs, int start, int end) { incrementPrefixes(cs, start, end, 1); } /** * Increments the count of all prefixes of the specified character sequence up to the maximum * length specified in the constructor. * * @param cs Underlying character array. * @param start Index of first character in slice. * @param end Index of one past last character in slice. * @param count Amount to increment. * @throws IndexOutOfBoundsException If the specified start and one plus end point are not in the * bounds of character sequence. */ public void incrementPrefixes(char[] cs, int start, int end, int count) { Strings.checkArgsStartEnd(cs, start, end); mRootNode = mRootNode.increment(cs, start, end, count); } /** * Decrements all of the substrings of the specified character slice by one. This method may be * used in conjunction with {@link #incrementSubstrings(char[],int,int)} to implement counts for * conditional probability estimates without affecting underlying estimates. For example, the * following code: * * <blockquote> * * <pre> * char[] cs = "abcdefghi".toCharArray(); * counter.incrementSubstrings(cs,3,7); * counter.decrementSubstrings(cs,3,5); * </pre> * * </blockquote> * * will increment the substrings of <code>"defg"</code> and then decrement the * substrings of <code>"de"</code>, causing the net effect of incrementing the counts of * substrings <code>"defg"</code>, <code>"efg"</code>, <code>"fg" * </code>, <code>"g"</code>, <code>"def"</code>, <code>"ef"</code>, * and <code>"f"</code>. This has the effect of increasing the estimate of <code>g * </code> given <code>def</code>, without increasing the estimate of <code>d</code> in an empty * context. * * @param cs Underlying array of characters in slice. * @param start Index of first character in slice. * @param end Index of one past last character in slice. * @throws IllegalArgumentException If the array slice is valid. */ public void decrementSubstrings(char[] cs, int start, int end) { Strings.checkArgsStartEnd(cs, start, end); for (int i = start; i < end; ++i) for (int j = i; j <= end; ++j) mRootNode = mRootNode.decrement(cs, i, j); } /** * Returns a string representation of the trie structure of counts underlying this counter. * * <p><b>Warning:</b> The resulting string will be very large if the number of substrings is * large. To avoid blowing out memory, do not call this method for large counters. * * @return String representation of this counter. */ @Override public String toString() { return mRootNode.toString(); } void toStringBuilder(StringBuilder sb) { mRootNode.toString(sb, 0); } /** * Decrements the unigram count for the specified character. This method is useful for training * conditional probabilities, even though it is not powerful enough to do it in full generality. * * @param c Decrement the unigram count for the specified character. */ public void decrementUnigram(char c) { decrementUnigram(c, 1); } /** * Decrements the unigram count by the specified amount for the specified character. This method * is useful for training conditional probabilities, even though it is not powerful enough to do * it in full generality. * * @param c Decrement the unigram count for the specified character. * @param count Amount to decrement. */ public void decrementUnigram(char c, int count) { mRootNode = mRootNode.decrement(new char[] {c}, 0, 1, count); } private List<Long> countsList(int nGramOrder) { List<Long> accum = new ArrayList<Long>(); mRootNode.addCounts(accum, nGramOrder); return accum; } /** * Writes an encoding of this counter to the specified output stream. It may be read back in using * {@link #readFrom(InputStream)}. * * <p>The output is produced using a {@link BitTrieWriter} wrapped around a {@link BitOutput} * wrapped around the specified underlying output stream. First, the bit output is used to * delta-code the maximum n-gram plus 1. Then, the trie is encoded as described in {@link * BitTrieWriter}. Finally, the bit output is flushed. The underlying output stream is neither * flushed nor closed, allowing them to be used for other pruposes after this counter is written. * * <p>If necessary for efficiency, streams should be buffered before being passed to this method. * * @param out Underlying output stream for writing. * @throws IOException If there is an underlying I/O error. */ public void writeTo(OutputStream out) throws IOException { BitOutput bitOut = new BitOutput(out); bitOut.writeDelta(mMaxLength + 1L); TrieWriter writer = new BitTrieWriter(bitOut); writeCounter(this, writer, mMaxLength); bitOut.flush(); } /** * Writes the specified sequence counter to the specified trie writer, restricting output to * n-grams not longer than the specified maximum. * * @param counter Counter to write. * @param writer Trie writer to which counter is written. * @param maxNGram Maximum length n-gram written. * @throws IOException If there is an underlying I/O error. */ public static void writeCounter(CharSeqCounter counter, TrieWriter writer, int maxNGram) throws IOException { writeCounter(new char[maxNGram], 0, counter, writer); } /** * Reads a trie character sequence counter from the specified input stream. * * <p>The expected encoding is described in {@link #writeTo(OutputStream)}. * * <p>If necessary for efficiency, streams should be buffered before being passed to this method. * * @param in Underlying input stream for reading. * @throws IOException If there is an underlying I/O error. */ public static TrieCharSeqCounter readFrom(InputStream in) throws IOException { BitInput bitIn = new BitInput(in); int maxNGram = (int) (bitIn.readDelta() - 1L); BitTrieReader reader = new BitTrieReader(bitIn); return readCounter(reader, maxNGram); } /** * Reads a trie character sequence counter from the specified trie reader, restricting the result * to the specified maximum n-gram. * * @param reader Reader from which to read the trie. * @param maxNGram Maximum length n-gram to read. * @return The counter read from the reader. * @throws IOException If there is an underlying I/O error. */ public static TrieCharSeqCounter readCounter(TrieReader reader, int maxNGram) throws IOException { TrieCharSeqCounter counter = new TrieCharSeqCounter(maxNGram); counter.mRootNode = readNode(reader, 0, maxNGram); return counter; } static void writeCounter(char[] cs, int pos, CharSeqCounter counter, TrieWriter writer) throws IOException { long count = counter.count(cs, 0, pos); writer.writeCount(count); if (pos < cs.length) { // daughters within n-gram bound char[] csNext = counter.charactersFollowing(cs, 0, pos); for (int i = 0; i < csNext.length; ++i) { writer.writeSymbol(csNext[i]); cs[pos] = csNext[i]; writeCounter(cs, pos + 1, counter, writer); } } writer.writeSymbol(-1L); // end of daughters } private static void skipNode(TrieReader reader) throws IOException { reader.readCount(); while (reader.readSymbol() != -1) skipNode(reader); } private static Node readNode(TrieReader reader, int depth, int maxDepth) throws IOException { if (depth > maxDepth) { skipNode(reader); return null; } long count = reader.readCount(); int depthPlus1 = depth + 1; long sym1 = reader.readSymbol(); // 0+ daughters if (sym1 == -1L) return NodeFactory.createNode(count); // 1+ daughters Node node1 = readNode(reader, depthPlus1, maxDepth); long sym2 = reader.readSymbol(); if (sym2 == -1L) return NodeFactory.createNodeFold((char) sym1, node1, count); Node node2 = readNode(reader, depthPlus1, maxDepth); long sym3 = reader.readSymbol(); if (sym3 == -1L) return NodeFactory.createNode((char) sym1, node1, (char) sym2, node2, count); Node node3 = readNode(reader, depthPlus1, maxDepth); long sym4 = reader.readSymbol(); if (sym4 == -1L) return NodeFactory.createNode( (char) sym1, node1, (char) sym2, node2, (char) sym3, node3, count); Node node4 = readNode(reader, depthPlus1, maxDepth); // 4+ daughters StringBuilder cBuf = new StringBuilder(); cBuf.append((char) sym1); cBuf.append((char) sym2); cBuf.append((char) sym3); cBuf.append((char) sym4); List<Node> nodeList = new ArrayList<Node>(); nodeList.add(node1); nodeList.add(node2); nodeList.add(node3); nodeList.add(node4); long sym; while ((sym = reader.readSymbol()) != -1L) { cBuf.append((char) sym); nodeList.add(readNode(reader, depthPlus1, maxDepth)); } Node[] nodes = nodeList.toArray(EMPTY_NODE_ARRAY); char[] cs = Strings.toCharArray(cBuf); return NodeFactory.createNode(cs, nodes, count); // > 3 daughters } static final Node[] EMPTY_NODE_ARRAY = new Node[0]; }