org.datavec.local.transforms.join.ExtractKeysFunction Maven / Gradle / Ivy
package org.datavec.local.transforms.join;
import lombok.AllArgsConstructor;
import org.datavec.api.writable.Writable;
import org.nd4j.linalg.function.Function;
import org.nd4j.linalg.primitives.Pair;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/** Created by huitseeker on 3/6/17. */
@AllArgsConstructor
public class ExtractKeysFunction implements Function, Pair, List>> {
private int[] columnIndexes;
@Override
public Pair, List> apply(List writables) {
List keyValues;
if (columnIndexes.length == 1) {
keyValues = Collections.singletonList(writables.get(columnIndexes[0]));
} else {
keyValues = new ArrayList<>(columnIndexes.length);
for (int i : columnIndexes) {
keyValues.add(writables.get(i));
}
}
return Pair.of(keyValues, writables);
}
}