    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017    package org.apache.commons.math3.linear;
    018
    019    import org.apache.commons.math3.Field;
    020    import org.apache.commons.math3.FieldElement;
    021    import org.apache.commons.math3.exception.DimensionMismatchException;
    022    import org.apache.commons.math3.exception.MathArithmeticException;
    023    import org.apache.commons.math3.exception.NotPositiveException;
    024    import org.apache.commons.math3.exception.NullArgumentException;
    025    import org.apache.commons.math3.exception.OutOfRangeException;
    026
    027    /**
    028     * Interface defining a field-valued vector with basic algebraic operations.
    029     * <p>
    030     * vector element indexing is 0-based -- e.g., <code>getEntry(0)</code>
    031     * returns the first element of the vector.
    032     * </p>
    033     * <p>
    034     * The various <code>mapXxx</code> and <code>mapXxxToSelf</code> methods operate
    035     * on vectors element-wise, i.e. they perform the same operation (adding a scalar,
    036     * applying a function ...) on each element in turn. The <code>mapXxx</code>
    037     * versions create a new vector to hold the result and do not change the instance.
    038     * The <code>mapXxxToSelf</code> versions use the instance itself to store the
    039     * results, so the instance is changed by these methods. In both cases, the result
    040     * vector is returned by the methods, this allows to use the <i>fluent API</i>
    041     * style, like this:
    042     * </p>
    043     * <pre>
    044     *   RealVector result = v.mapAddToSelf(3.0).mapTanToSelf().mapSquareToSelf();
    045     * </pre>
    046     *
    047     * @param <T> the type of the field elements
    048     * @version $Id: FieldVector.java 1416643 2012-12-03 19:37:14Z tn $
    049     * @since 2.0
    050     */
    051    public interface FieldVector<T extends FieldElement<T>>  {
    052
    053        /**
    054         * Get the type of field elements of the vector.
    055         * @return type of field elements of the vector
    056         */
    057        Field<T> getField();
    058
    059        /**
    060         * Returns a (deep) copy of this.
    061         * @return vector copy
    062         */
    063        FieldVector<T> copy();
    064
    065        /**
    066         * Compute the sum of {@code this} and {@code v}.
    067         * @param v vector to be added
    068         * @return {@code this + v}
    069         * @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
    070         */
    071        FieldVector<T> add(FieldVector<T> v) throws DimensionMismatchException;
    072
    073        /**
    074         * Compute {@code this} minus {@code v}.
    075         * @param v vector to be subtracted
    076         * @return {@code this - v}
    077         * @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
    078         */
    079        FieldVector<T> subtract(FieldVector<T> v) throws DimensionMismatchException;
    080
    081        /**
    082         * Map an addition operation to each entry.
    083         * @param d value to be added to each entry
    084         * @return {@code this + d}
    085         * @throws NullArgumentException if {@code d} is {@code null}.
    086         */
    087        FieldVector<T> mapAdd(T d) throws NullArgumentException;
    088
    089        /**
    090         * Map an addition operation to each entry.
    091         * <p>The instance <strong>is</strong> changed by this method.</p>
    092         * @param d value to be added to each entry
    093         * @return for convenience, return {@code this}
    094         * @throws NullArgumentException if {@code d} is {@code null}.
    095         */
    096        FieldVector<T> mapAddToSelf(T d) throws NullArgumentException;
    097
    098        /**
    099         * Map a subtraction operation to each entry.
    100         * @param d value to be subtracted to each entry
    101         * @return {@code this - d}
    102         * @throws NullArgumentException if {@code d} is {@code null}
    103         */
    104        FieldVector<T> mapSubtract(T d) throws NullArgumentException;
    105
    106        /**
    107         * Map a subtraction operation to each entry.
    108         * <p>The instance <strong>is</strong> changed by this method.</p>
    109         * @param d value to be subtracted to each entry
    110         * @return for convenience, return {@code this}
    111         * @throws NullArgumentException if {@code d} is {@code null}
    112         */
    113        FieldVector<T> mapSubtractToSelf(T d) throws NullArgumentException;
    114
    115        /**
    116         * Map a multiplication operation to each entry.
    117         * @param d value to multiply all entries by
    118         * @return {@code this * d}
    119         * @throws NullArgumentException if {@code d} is {@code null}.
    120         */
    121        FieldVector<T> mapMultiply(T d) throws NullArgumentException;
    122
    123        /**
    124         * Map a multiplication operation to each entry.
    125         * <p>The instance <strong>is</strong> changed by this method.</p>
    126         * @param d value to multiply all entries by
    127         * @return for convenience, return {@code this}
    128         * @throws NullArgumentException if {@code d} is {@code null}.
    129         */
    130        FieldVector<T> mapMultiplyToSelf(T d) throws NullArgumentException;
    131
    132        /**
    133         * Map a division operation to each entry.
    134         * @param d value to divide all entries by
    135         * @return {@code this / d}
    136         * @throws NullArgumentException if {@code d} is {@code null}.
    137         * @throws MathArithmeticException if {@code d} is zero.
    138         */
    139        FieldVector<T> mapDivide(T d)
    140            throws NullArgumentException, MathArithmeticException;
    141
    142        /**
    143         * Map a division operation to each entry.
    144         * <p>The instance <strong>is</strong> changed by this method.</p>
    145         * @param d value to divide all entries by
    146         * @return for convenience, return {@code this}
    147         * @throws NullArgumentException if {@code d} is {@code null}.
    148         * @throws MathArithmeticException if {@code d} is zero.
    149         */
    150        FieldVector<T> mapDivideToSelf(T d)
    151            throws NullArgumentException, MathArithmeticException;
    152
    153        /**
    154         * Map the 1/x function to each entry.
    155         * @return a vector containing the result of applying the function to each entry.
    156         * @throws MathArithmeticException if one of the entries is zero.
    157         */
    158        FieldVector<T> mapInv() throws MathArithmeticException;
    159
    160        /**
    161         * Map the 1/x function to each entry.
    162         * <p>The instance <strong>is</strong> changed by this method.</p>
    163         * @return for convenience, return {@code this}
    164         * @throws MathArithmeticException if one of the entries is zero.
    165         */
    166        FieldVector<T> mapInvToSelf() throws MathArithmeticException;
    167
    168        /**
    169         * Element-by-element multiplication.
    170         * @param v vector by which instance elements must be multiplied
    171         * @return a vector containing {@code this[i] * v[i]} for all {@code i}
    172         * @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
    173         */
    174        FieldVector<T> ebeMultiply(FieldVector<T> v)
    175            throws DimensionMismatchException;
    176
    177        /**
    178         * Element-by-element division.
    179         * @param v vector by which instance elements must be divided
    180         * @return a vector containing {@code this[i] / v[i]} for all {@code i}
    181         * @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
    182         * @throws MathArithmeticException if one entry of {@code v} is zero.
    183         */
    184        FieldVector<T> ebeDivide(FieldVector<T> v)
    185            throws DimensionMismatchException, MathArithmeticException;
    186
    187        /**
    188         * Returns vector entries as a T array.
    189         * @return T array of entries
    190         * @deprecated as of 3.1, to be removed in 4.0. Please use the {@link #toArray()} method instead.
    191         */
    192        @Deprecated
    193        T[] getData();
    194
    195        /**
    196         * Compute the dot product.
    197         * @param v vector with which dot product should be computed
    198         * @return the scalar dot product of {@code this} and {@code v}
    199         * @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
    200         */
    201        T dotProduct(FieldVector<T> v) throws DimensionMismatchException;
    202
    203        /**
    204         * Find the orthogonal projection of this vector onto another vector.
    205         * @param v vector onto which {@code this} must be projected
    206         * @return projection of {@code this} onto {@code v}
    207         * @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
    208         * @throws MathArithmeticException if {@code v} is the null vector.
    209         */
    210        FieldVector<T> projection(FieldVector<T> v)
    211            throws DimensionMismatchException, MathArithmeticException;
    212
    213        /**
    214         * Compute the outer product.
    215         * @param v vector with which outer product should be computed
    216         * @return the matrix outer product between instance and v
    217         */
    218        FieldMatrix<T> outerProduct(FieldVector<T> v);
    219
    220        /**
    221         * Returns the entry in the specified index.
    222         *
    223         * @param index Index location of entry to be fetched.
    224         * @return the vector entry at {@code index}.
    225         * @throws OutOfRangeException if the index is not valid.
    226         * @see #setEntry(int, FieldElement)
    227         */
    228        T getEntry(int index) throws OutOfRangeException;
    229
    230        /**
    231         * Set a single element.
    232         * @param index element index.
    233         * @param value new value for the element.
    234         * @throws OutOfRangeException if the index is not valid.
    235         * @see #getEntry(int)
    236         */
    237        void setEntry(int index, T value) throws OutOfRangeException;
    238
    239        /**
    240         * Returns the size of the vector.
    241         * @return size
    242         */
    243        int getDimension();
    244
    245        /**
    246         * Construct a vector by appending a vector to this vector.
    247         * @param v vector to append to this one.
    248         * @return a new vector
    249         */
    250        FieldVector<T> append(FieldVector<T> v);
    251
    252        /**
    253         * Construct a vector by appending a T to this vector.
    254         * @param d T to append.
    255         * @return a new vector
    256         */
    257        FieldVector<T> append(T d);
    258
    259        /**
    260         * Get a subvector from consecutive elements.
    261         * @param index index of first element.
    262         * @param n number of elements to be retrieved.
    263         * @return a vector containing n elements.
    264         * @throws OutOfRangeException if the index is not valid.
    265         * @throws NotPositiveException if the number of elements if not positive.
    266         */
    267        FieldVector<T> getSubVector(int index, int n)
    268            throws OutOfRangeException, NotPositiveException;
    269
    270        /**
    271         * Set a set of consecutive elements.
    272         * @param index index of first element to be set.
    273         * @param v vector containing the values to set.
    274         * @throws OutOfRangeException if the index is not valid.
    275         */
    276        void setSubVector(int index, FieldVector<T> v) throws OutOfRangeException;
    277
    278        /**
    279         * Set all elements to a single value.
    280         * @param value single value to set for all elements
    281         */
    282        void set(T value);
    283
    284        /**
    285         * Convert the vector to a T array.
    286         * <p>The array is independent from vector data, it's elements
    287         * are copied.</p>
    288         * @return array containing a copy of vector elements
    289         */
    290        T[] toArray();
    291
    292    }