/*
* Copyright 2014 Red Hat, Inc. and/or its affiliates.
*
* Licensed 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.dashbuilder.dataset.engine.function;
import java.util.Iterator;
import java.util.List;
import org.dashbuilder.dataset.ColumnType;
import org.dashbuilder.dataset.group.AggregateFunctionType;
/**
* It calculates the min. number of a set of numbers.
*/
public class MinFunction extends AbstractFunction {
public MinFunction() {
super();
}
public AggregateFunctionType getType() {
return AggregateFunctionType.MIN;
}
public double aggregate(List values) {
if (values == null || values.isEmpty()) return 0;
// Get the min. value from the collection.
Number min = null;
Iterator it = values.iterator();
while (it.hasNext()) {
Number n = (Number) it.next();
if (n == null) continue;
if (min == null || n.doubleValue() < min.doubleValue()) min = n;
}
// Adjust to the specified precision.
if (min == null) return 0;
return round(min.doubleValue(), precission);
}
public double aggregate(List values, List<Integer> rows) {
if (rows == null) return aggregate(values);
if (rows.isEmpty()) return 0;
if (values == null || values.isEmpty()) return 0;
// Get the min. value from the collection.
Number min = null;
for (Integer row : rows) {
Number n = (Number) values.get(row);
if (n == null) continue;
if (min == null || n.doubleValue() < min.doubleValue()) min = n;
}
// Adjust to the specified precision.
if (min == null) return 0;
return round(min.doubleValue(), precission);
}
}