Examples of Accumulator

com.facebook.presto.operator.aggregation.Accumulator
com.hp.hpl.jena.sparql.expr.aggregate.Accumulator
An Accumulator is the processor for each section of a group, so there is one Accumulator for each group key.
com.persistit.Accumulator

An Accumulator accumulates statistical information in the MVCC Transaction environment without creating write-write dependency conflicts. Subclasses include SumAccumulator, MinAccumulator, MaxAccumulator and SeqAccumulator which compute the sum, minimum and maximum values of contributions by individual transactions. (See below for semantics of the SeqAccummulator.) Each contribution is accounted for separately as a Delta instance until the transaction is either committed or aborted and there are no other concurrently executing transactions that started before the commit timestamp. This mechanism is designed to provide a "snapshot" view of the Accumulator that is consistent with the snapshot view of the database.

In more detail: each type of Accumulator has an update method that may only be invoked within the scope of a transaction T. That update is not visible to any other transaction until T commits. Moreover, any other concurrently executing transaction having a start timestamp less than T's commit timestamp does not see the results of the update. To accomplish this, the state of the Accumulator visible within a transaction is computed by determining which updates are visible and aggregating them on demand.

The updates invoked on committed Transactions are recorded in the Journal and reapplied during recovery to reproduce an accurate version of the Accumulator state when Persistit starts up. There can be at most 64 Accumulators per Tree. A snapshot value of each Accumulator is stored once per checkpoint. Checkpoint snapshot values are held in the directory tree of the volume containing the Tree.

Types of Accumulators
The following defines intended use cases for the various types of accumulators:

{@link com.persistit.Accumulator.Type#SUM}

Row count, total size, sums of various other characteristics

{@link com.persistit.Accumulator.Type#MAX}

Maximum value

{@link com.persistit.Accumulator.Type#MIN}

Minimum value

{@link com.persistit.Accumulator.Type#SEQ}

Sequence number generation, e.g., auto-increment or internal primary key assignment

Snapshot and Live Values
Each Accumulator type supplies both a "snapshot" value and a "live" value. The snapshot value is computed as described above by selectively applying only those updates visible to the transaction. The live value, however, is simply the result of applying each update operation atomically to a long value maintained by the Accumulator. For example, if ten transactions increment a SUM accumulator by one, and then five commit of them and five and roll back, the live value is nonetheless increased by ten. Thus the live value is only an estimate. Its value is cheap to acquire but not transactionally accurate.

SeqAccumulator
The SeqAccumulator is a combination of SumAccumulator and MaxAccumulator. When the {@link com.persistit.Accumulator.SeqAccumulator#allocate()} method is called,the Accumulator's live value is atomically incremented and the resulting value is returned. In addition, a Delta holding the resulting sum as a proposed minimum value is added to the transaction. These semantics guarantee that every value returned by a SeqAccumulator (within a transaction that actually commits) is unique, and that upon recovery after a normal shutdown or crash, the first value returned will be larger than the maximum value assigned by any transaction that committed successfully before the shutdown. Note that a transaction that allocates a value and then aborts leaves a gap in the numerical sequence.
@author peter

ivory.smrf.retrieval.Accumulator
@author Don Metzler
org.broad.igv.tdf.Accumulator
Accumulator for a single window function.
Estimating percentiles -- weighted average of multiple estimates @author jrobinso
org.drools.core.spi.Accumulator
Accumulator Created: 04/06/2006 @version $Id$
org.drools.spi.Accumulator
Accumulator Created: 04/06/2006 @author Edson Tirelli @version $Id: Accumulator.java 23634 2008-10-30 15:20:58Z mark.proctor@jboss.com $
org.rascalmpl.interpreter.Accumulator
org.shiftone.jrat.core.Accumulator
Class Accumulator @author $Author: jeffdrost $ @version $Revision: 1.30 $
org.simpleframework.http.core.Accumulator
The Accumulator object is an output stream that can buffer bytes written up to a given size. This is used if a buffer is requested for the response output. Such a mechanism allows the response to be written without committing the response. Also it enables content that has been written to be reset, by simply clearing the accumulator buffer. Once the accumulator buffer has overflown then the response is committed. @author Niall Gallagher @see org.simpleframework.http.core.Transfer
se.grunka.fortuna.accumulator.Accumulator

Examples of ivory.smrf.retrieval.Accumulator

        int size = sortedConcepts.size();
        if (size < curFbTerms || sortedConcepts.peek().score < score) {
          if (size == curFbTerms) {
            sortedConcepts.poll(); // Remove worst concept.
          }
          sortedConcepts.add(new Accumulator(conceptID, score));
        }
      }


      // Compute the weights of the expanded terms.
      int numTerms = Math.min(curFbTerms, sortedConcepts.size());
      float totalWt = 0.0f;
      Accumulator[] bestConcepts = new Accumulator[numTerms];
      for (int i = 0; i < numTerms; i++) {
        Accumulator a = sortedConcepts.poll();
        bestConcepts[i] = a;
        totalWt += a.score;
      }


      // Add cliques corresponding to best expansion concepts.
      for (int i = 0; i < numTerms; i++) {
        Accumulator a = bestConcepts[i];


        // Construct the MRF corresponding to this concept.
        String[] concepts = vocab[a.docno].getKey().split(" ");
        MarkovRandomField conceptMRF = curBuilder.buildMRF(concepts);

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Examples of ivory.smrf.retrieval.Accumulator

      int size = sortedConcepts.size();
      if (size < numFeedbackTerms || sortedConcepts.peek().score < score) {
        if (size == numFeedbackTerms) {
          sortedConcepts.poll(); // Remove worst concept.
        }
        sortedConcepts.add(new Accumulator(conceptID, score));
      }
    }


    // Compute the weights of the expanded terms.
    int numTerms = Math.min(numFeedbackTerms, sortedConcepts.size());
    float totalWt = 0.0f;
    Accumulator[] bestConcepts = new Accumulator[numTerms];
    for (int i = 0; i < numTerms; i++) {
      Accumulator a = sortedConcepts.poll();
      bestConcepts[i] = a;
      totalWt += a.score;
    }


    // Document node (shared across all expansion cliques).
    DocumentNode docNode = new DocumentNode();


    // Expression generator (shared across all expansion cliques).
    ExpressionGenerator generator = new TermExpressionGenerator();


    // Add cliques corresponding to best expansion concepts.
    for (int i = 0; i < numTerms; i++) {
      Accumulator a = bestConcepts[i];


      // Construct the MRF corresponding to this concept.
      String concept = vocab[a.docno].getKey();


      for (int j = 0; j < scoringFunctionNodes.size(); j++) {

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Examples of ivory.smrf.retrieval.Accumulator

          sumSq += score * score;
          i++;
          String originalDocID = lines[i];
          docnoMapping.put(new Integer(docid), originalDocID);
          i++;
          results[j] = new Accumulator(docid, score);
          j++;


        }
        int n = results.length;
        float muo = sum / n;

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Examples of ivory.smrf.retrieval.Accumulator

            min = score;
          i++;
          String originalDocID = lines[i];
          docnoMapping.put(new Integer(docid), originalDocID);
          i++;
          results[j] = new Accumulator(docid, score);
          j++;


        }
        float d = max - min;
        for (Accumulator a : results) {

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Examples of ivory.smrf.retrieval.Accumulator

          float score = Float.parseFloat(lines[i]);
          i++;
          String originalDocID = lines[i];
          docnoMapping.put(new Integer(docid), originalDocID);
          i++;
          results[j] = new Accumulator(docid, score);
          j++;
        }
        sLogger.info("returning original scores.");
        return results;
      }

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Examples of ivory.smrf.retrieval.Accumulator

        }
        continue;
      }
      String[] s = lines[i].split("\t");


      r.add(new Accumulator(Integer.parseInt(s[0]), Float.parseFloat(s[1])));
      docnoMapping.put(Integer.parseInt(s[0]), s[2]);
    }
    Accumulator[] results = new Accumulator[r.size()];
    for (int i = 0; i < r.size(); i++)
      results[i] = r.get(i);

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Examples of ivory.smrf.retrieval.Accumulator

        int size = sortedConcepts.size();
        if (size < curFbTerms || sortedConcepts.peek().score < score) {
          if (size == curFbTerms) {
            sortedConcepts.poll(); // Remove worst concept.
          }
          sortedConcepts.add(new Accumulator(conceptID, score));
        }
      }


      // Compute the weights of the expanded terms.
      int numTerms = Math.min(curFbTerms, sortedConcepts.size());
      float totalWt = 0.0f;
      Accumulator[] bestConcepts = new Accumulator[numTerms];
      for (int i = 0; i < numTerms; i++) {
        Accumulator a = sortedConcepts.poll();
        bestConcepts[i] = a;
        totalWt += a.score;
      }


      // Add cliques corresponding to best expansion concepts.
      for (int i = 0; i < numTerms; i++) {
        Accumulator a = bestConcepts[i];


        // Construct the MRF corresponding to this concept.
        String[] concepts = vocab[a.docno].getKey().split(" ");
        MarkovRandomField conceptMRF = curBuilder.buildMRF(concepts);

View Full Code Here

Examples of ivory.smrf.retrieval.Accumulator

      int size = sortedConcepts.size();
      if (size < numFeedbackTerms || sortedConcepts.peek().score < score) {
        if (size == numFeedbackTerms) {
          sortedConcepts.poll(); // Remove worst concept.
        }
        sortedConcepts.add(new Accumulator(conceptID, score));
      }
    }


    // Compute the weights of the expanded terms.
    int numTerms = Math.min(numFeedbackTerms, sortedConcepts.size());
    float totalWt = 0.0f;
    Accumulator[] bestConcepts = new Accumulator[numTerms];
    for (int i = 0; i < numTerms; i++) {
      Accumulator a = sortedConcepts.poll();
      bestConcepts[i] = a;
      totalWt += a.score;
    }


    // Document node (shared across all expansion cliques).
    DocumentNode docNode = new DocumentNode();


    // Expression generator (shared across all expansion cliques).
    ExpressionGenerator generator = new TermExpressionGenerator();


    // Add cliques corresponding to best expansion concepts.
    for (int i = 0; i < numTerms; i++) {
      Accumulator a = bestConcepts[i];


      // Construct the MRF corresponding to this concept.
      String concept = vocab[a.docno].getKey();


      for (int j = 0; j < scoringFunctionNodes.size(); j++) {

View Full Code Here

Examples of ivory.smrf.retrieval.Accumulator

          sumSq += score * score;
          i++;
          String originalDocID = lines[i];
          docnoMapping.put(new Integer(docid), originalDocID);
          i++;
          results[j] = new Accumulator(docid, score);
          j++;


        }
        int n = results.length;
        float muo = sum / n;

View Full Code Here

Examples of ivory.smrf.retrieval.Accumulator

            min = score;
          i++;
          String originalDocID = lines[i];
          docnoMapping.put(new Integer(docid), originalDocID);
          i++;
          results[j] = new Accumulator(docid, score);
          j++;


        }
        float d = max - min;
        for (Accumulator a : results) {

View Full Code Here

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Examples of Accumulator

Types of Accumulators

Snapshot and Live Values

SeqAccumulator

Examples of ivory.smrf.retrieval.Accumulator

Examples of ivory.smrf.retrieval.Accumulator

Examples of ivory.smrf.retrieval.Accumulator

Examples of ivory.smrf.retrieval.Accumulator

Examples of ivory.smrf.retrieval.Accumulator

Examples of ivory.smrf.retrieval.Accumulator

Examples of ivory.smrf.retrieval.Accumulator

Examples of ivory.smrf.retrieval.Accumulator

Examples of ivory.smrf.retrieval.Accumulator

Examples of ivory.smrf.retrieval.Accumulator