ajs6f commented on a change in pull request #568: Add Aggregate Median to SPARQL ARQ syntax URL: https://github.com/apache/jena/pull/568#discussion_r292554057
########## File path: jena-arq/src/main/java/org/apache/jena/sparql/expr/aggregate/AggModeDistinct.java ########## @@ -0,0 +1,126 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * 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 org.apache.jena.sparql.expr.aggregate; + +import java.util.ArrayList; +import java.util.Arrays; + +import org.apache.jena.graph.Node ; +import org.apache.jena.sparql.engine.binding.Binding ; +import org.apache.jena.sparql.expr.Expr ; +import org.apache.jena.sparql.expr.ExprEvalException ; +import org.apache.jena.sparql.expr.ExprList ; +import org.apache.jena.sparql.expr.NodeValue ; +import org.apache.jena.sparql.expr.nodevalue.XSDFuncOp ; +import org.apache.jena.sparql.function.FunctionEnv ; +import org.slf4j.Logger ; +import org.slf4j.LoggerFactory ; + +public class AggModeDistinct extends AggregatorBase +{ + // ---- Mode (DISTINCT expr) + private static Logger log = LoggerFactory.getLogger("ModeDistinct") ; + + public AggModeDistinct(Expr expr) { super("Mode", true, expr) ; } + @Override + public Aggregator copy(ExprList expr) { return new AggModeDistinct(expr.get(0)) ; } + + private static final NodeValue noValuesToMode = NodeValue.nvZERO ; + + @Override + public Accumulator createAccumulator() + { + return new AccModeDistinct(getExpr()) ; + } + + @Override + public Node getValueEmpty() { return NodeValue.toNode(noValuesToMode) ; } + + @Override + public int hashCode() { + return HC_AggModeDistinct ^ getExprList().hashCode() ; + } + + @Override + public boolean equals(Aggregator other, boolean bySyntax) { + if ( other == null ) return false ; + if ( this == other ) return true ; + if ( ! ( other instanceof AggModeDistinct ) ) return false ; + AggModeDistinct a = (AggModeDistinct)other ; + return exprList.equals(a.exprList, bySyntax) ; + } + + + // ---- Accumulator + class AccModeDistinct extends AccumulatorExpr + { + // Non-empty case but still can be nothing because the expression may be undefined. + private NodeValue total = noValuesToMode ; + private int count = 0 ; + ArrayList<NodeValue> collection=new ArrayList<NodeValue>(); + + public AccModeDistinct(Expr expr) { super(expr, true) ; } + + @Override + protected void accumulate(NodeValue nv, Binding binding, FunctionEnv functionEnv) + { + log.debug("mode {}", nv); + + if ( nv.isNumber() ) + { + count++ ; + collection.add(nv); + } + else + throw new ExprEvalException("mode: not a number: "+nv) ; + + log.debug("mode count {}", count); + } + + @Override + public NodeValue getAccValue() + { + double mode; + if ( count == 0 ) return noValuesToMode ; + if ( super.errorCount != 0 ) + return null ; + + int indexsize = collection.size(); + double[] arrDouble = new double[indexsize]; + for(int i=0; i<indexsize; i++){ + arrDouble[i] = collection.get(i).getDouble(); + } + + Arrays.sort(arrDouble); + if(indexsize==0) { + mode = Double.NaN; + }else if(indexsize%2!=0) { + mode = arrDouble[(indexsize/2)]; + }else { + mode = ((arrDouble[(indexsize/2)]+arrDouble[((indexsize/2)-1)])/2); + } + + return (NodeValue.makeDecimal((mode))); Review comment: Extra () ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
