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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package opennlp.model;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Abstract class for collecting event and context counts used in training.
*
*/
public abstract class AbstractDataIndexer implements DataIndexer {
private int numEvents;
/** The integer contexts associated with each unique event. */
protected int[][] contexts;
/** The integer outcome associated with each unique event. */
protected int[] outcomeList;
/** The number of times an event occured in the training data. */
protected int[] numTimesEventsSeen;
/** The predicate/context names. */
protected String[] predLabels;
/** The names of the outcomes. */
protected String[] outcomeLabels;
/** The number of times each predicate occured. */
protected int[] predCounts;
public int[][] getContexts() {
return contexts;
}
public int[] getNumTimesEventsSeen() {
return numTimesEventsSeen;
}
public int[] getOutcomeList() {
return outcomeList;
}
public String[] getPredLabels() {
return predLabels;
}
public String[] getOutcomeLabels() {
return outcomeLabels;
}
public int[] getPredCounts() {
return predCounts;
}
/**
* Sorts and uniques the array of comparable events and return the number of unique events.
* This method will alter the eventsToCompare array -- it does an in place
* sort, followed by an in place edit to remove duplicates.
*
* @param eventsToCompare a ComparableEvent[]
value
* @return The number of unique events in the specified list.
* @since maxent 1.2.6
*/
protected int sortAndMerge(List eventsToCompare, boolean sort) {
int numUniqueEvents = 1;
numEvents = eventsToCompare.size();
if (sort) {
Collections.sort(eventsToCompare);
if (numEvents <= 1) {
return numUniqueEvents; // nothing to do; edge case (see assertion)
}
ComparableEvent ce = eventsToCompare.get(0);
for (int i = 1; i < numEvents; i++) {
ComparableEvent ce2 = eventsToCompare.get(i);
if (ce.compareTo(ce2) == 0) {
ce.seen++; // increment the seen count
eventsToCompare.set(i, null); // kill the duplicate
}
else {
ce = ce2; // a new champion emerges...
numUniqueEvents++; // increment the # of unique events
}
}
}
else {
numUniqueEvents = eventsToCompare.size();
}
if (sort) System.out.println("done. Reduced " + numEvents + " events to " + numUniqueEvents + ".");
contexts = new int[numUniqueEvents][];
outcomeList = new int[numUniqueEvents];
numTimesEventsSeen = new int[numUniqueEvents];
for (int i = 0, j = 0; i < numEvents; i++) {
ComparableEvent evt = eventsToCompare.get(i);
if (null == evt) {
continue; // this was a dupe, skip over it.
}
numTimesEventsSeen[j] = evt.seen;
outcomeList[j] = evt.outcome;
contexts[j] = evt.predIndexes;
++j;
}
return numUniqueEvents;
}
public int getNumEvents() {
return numEvents;
}
/**
* Updates the set of predicated and counter with the specified event contexts and cutoff.
* @param ec The contexts/features which occur in a event.
* @param predicateSet The set of predicates which will be used for model building.
* @param counter The predicate counters.
* @param cutoff The cutoff which determines whether a predicate is included.
*/
protected static void update(String[] ec, Set predicateSet, Map counter, int cutoff) {
for (String s : ec) {
Integer i = counter.get(s);
if (i == null) {
counter.put(s, 1);
}
else {
counter.put(s, i + 1);
}
if (!predicateSet.contains(s) && counter.get(s) >= cutoff) {
predicateSet.add(s);
}
}
}
/**
* Utility method for creating a String[] array from a map whose
* keys are labels (Strings) to be stored in the array and whose
* values are the indices (Integers) at which the corresponding
* labels should be inserted.
*
* @param labelToIndexMap a TObjectIntHashMap
value
* @return a String[]
value
* @since maxent 1.2.6
*/
protected static String[] toIndexedStringArray(Map labelToIndexMap) {
final String[] array = new String[labelToIndexMap.size()];
for (String label : labelToIndexMap.keySet()) {
array[labelToIndexMap.get(label)] = label;
}
return array;
}
public float[][] getValues() {
return null;
}
}
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