SingleElementVector.java

/*
 * 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.ignite.ml.math.impls.vector;

import java.util.Map;
import org.apache.ignite.ml.math.Matrix;
import org.apache.ignite.ml.math.Vector;
import org.apache.ignite.ml.math.exceptions.UnsupportedOperationException;
import org.apache.ignite.ml.math.impls.storage.vector.SingleElementVectorStorage;

/**
 * Read-write vector holding a single non-zero value at some index.
 */
public class SingleElementVector extends AbstractVector {
    /**
     *
     */
    public SingleElementVector() {
        // No-op
    }

    /**
     * @param size Parent vector size.
     * @param idx Index of the parent vector element.
     * @param val Value of the vector element.
     */
    public SingleElementVector(int size, int idx, double val) {
        super(new SingleElementVectorStorage(size, idx, val));
    }

    /**
     * @param args Parameters to create new vector instance.
     */
    public SingleElementVector(Map<String, Object> args) {
        assert args != null;

        if (args.containsKey("size") && args.containsKey("index") && args.containsKey("value")) {
            int size = (int)args.get("size");
            int idx = (int)args.get("index");
            double val = (double)args.get("value");

            setStorage(new SingleElementVectorStorage(size, idx, val));
        }
        else
            throw new UnsupportedOperationException("Invalid constructor argument(s).");
    }

    /**
     *
     *
     */
    private SingleElementVectorStorage storage() {
        return (SingleElementVectorStorage)getStorage();
    }

    /** {@inheritDoc} */
    @Override public Element minElement() {
        return makeElement(storage().index());
    }

    /** {@inheritDoc} */
    @Override public Element maxElement() {
        return makeElement(storage().index());
    }

    /** {@inheritDoc} */
    @Override public double sum() {
        return getX(storage().index());
    }

    /** {@inheritDoc} */
    @Override public int nonZeroElements() {
        return isZero(get(storage().index())) ? 0 : 1;
    }

    /** {@inheritDoc} */
    @Override public Vector like(int crd) {
        int idx = storage().index();

        return new SingleElementVector(crd, idx, getX(idx));
    }

    /** {@inheritDoc} */
    @Override public Matrix likeMatrix(int rows, int cols) {
        throw new UnsupportedOperationException();
    }
}