/*
* 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.commons.math3.linear;
import org.apache.commons.math3.Field;
import org.apache.commons.math3.FieldElement;
import org.apache.commons.math3.exception.DimensionMismatchException;
import org.apache.commons.math3.exception.MathArithmeticException;
import org.apache.commons.math3.exception.NotPositiveException;
import org.apache.commons.math3.exception.NullArgumentException;
import org.apache.commons.math3.exception.OutOfRangeException;
/**
* Interface defining a field-valued vector with basic algebraic operations.
* <p>
* vector element indexing is 0-based -- e.g., <code>getEntry(0)</code>
* returns the first element of the vector.
* </p>
* <p>
* The various <code>mapXxx</code> and <code>mapXxxToSelf</code> methods operate
* on vectors element-wise, i.e. they perform the same operation (adding a scalar,
* applying a function ...) on each element in turn. The <code>mapXxx</code>
* versions create a new vector to hold the result and do not change the instance.
* The <code>mapXxxToSelf</code> versions use the instance itself to store the
* results, so the instance is changed by these methods. In both cases, the result
* vector is returned by the methods, this allows to use the <i>fluent API</i>
* style, like this:
* </p>
* <pre>
* RealVector result = v.mapAddToSelf(3.0).mapTanToSelf().mapSquareToSelf();
* </pre>
* <p>
* Note that as almost all operations on {@link FieldElement} throw {@link
* NullArgumentException} when operating on a null element, it is the responsibility
* of <code>FieldVector</code> implementations to make sure no null elements
* are inserted into the vector. This must be done in all constructors and
* all setters.
* <p>
*
* @param <T> the type of the field elements
* @since 2.0
*/
public interface FieldVector<T extends FieldElement<T>> {
/**
* Get the type of field elements of the vector.
* @return type of field elements of the vector
*/
Field<T> getField();
/**
* Returns a (deep) copy of this.
* @return vector copy
*/
FieldVector<T> copy();
/**
* Compute the sum of {@code this} and {@code v}.
* @param v vector to be added
* @return {@code this + v}
* @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
*/
FieldVector<T> add(FieldVector<T> v) throws DimensionMismatchException;
/**
* Compute {@code this} minus {@code v}.
* @param v vector to be subtracted
* @return {@code this - v}
* @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
*/
FieldVector<T> subtract(FieldVector<T> v) throws DimensionMismatchException;
/**
* Map an addition operation to each entry.
* @param d value to be added to each entry
* @return {@code this + d}
* @throws NullArgumentException if {@code d} is {@code null}.
*/
FieldVector<T> mapAdd(T d) throws NullArgumentException;
/**
* Map an addition operation to each entry.
* <p>The instance <strong>is</strong> changed by this method.</p>
* @param d value to be added to each entry
* @return for convenience, return {@code this}
* @throws NullArgumentException if {@code d} is {@code null}.
*/
FieldVector<T> mapAddToSelf(T d) throws NullArgumentException;
/**
* Map a subtraction operation to each entry.
* @param d value to be subtracted to each entry
* @return {@code this - d}
* @throws NullArgumentException if {@code d} is {@code null}
*/
FieldVector<T> mapSubtract(T d) throws NullArgumentException;
/**
* Map a subtraction operation to each entry.
* <p>The instance <strong>is</strong> changed by this method.</p>
* @param d value to be subtracted to each entry
* @return for convenience, return {@code this}
* @throws NullArgumentException if {@code d} is {@code null}
*/
FieldVector<T> mapSubtractToSelf(T d) throws NullArgumentException;
/**
* Map a multiplication operation to each entry.
* @param d value to multiply all entries by
* @return {@code this * d}
* @throws NullArgumentException if {@code d} is {@code null}.
*/
FieldVector<T> mapMultiply(T d) throws NullArgumentException;
/**
* Map a multiplication operation to each entry.
* <p>The instance <strong>is</strong> changed by this method.</p>
* @param d value to multiply all entries by
* @return for convenience, return {@code this}
* @throws NullArgumentException if {@code d} is {@code null}.
*/
FieldVector<T> mapMultiplyToSelf(T d) throws NullArgumentException;
/**
* Map a division operation to each entry.
* @param d value to divide all entries by
* @return {@code this / d}
* @throws NullArgumentException if {@code d} is {@code null}.
* @throws MathArithmeticException if {@code d} is zero.
*/
FieldVector<T> mapDivide(T d)
throws NullArgumentException, MathArithmeticException;
/**
* Map a division operation to each entry.
* <p>The instance <strong>is</strong> changed by this method.</p>
* @param d value to divide all entries by
* @return for convenience, return {@code this}
* @throws NullArgumentException if {@code d} is {@code null}.
* @throws MathArithmeticException if {@code d} is zero.
*/
FieldVector<T> mapDivideToSelf(T d)
throws NullArgumentException, MathArithmeticException;
/**
* Map the 1/x function to each entry.
* @return a vector containing the result of applying the function to each entry.
* @throws MathArithmeticException if one of the entries is zero.
*/
FieldVector<T> mapInv() throws MathArithmeticException;
/**
* Map the 1/x function to each entry.
* <p>The instance <strong>is</strong> changed by this method.</p>
* @return for convenience, return {@code this}
* @throws MathArithmeticException if one of the entries is zero.
*/
FieldVector<T> mapInvToSelf() throws MathArithmeticException;
/**
* Element-by-element multiplication.
* @param v vector by which instance elements must be multiplied
* @return a vector containing {@code this[i] * v[i]} for all {@code i}
* @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
*/
FieldVector<T> ebeMultiply(FieldVector<T> v)
throws DimensionMismatchException;
/**
* Element-by-element division.
* @param v vector by which instance elements must be divided
* @return a vector containing {@code this[i] / v[i]} for all {@code i}
* @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
* @throws MathArithmeticException if one entry of {@code v} is zero.
*/
FieldVector<T> ebeDivide(FieldVector<T> v)
throws DimensionMismatchException, MathArithmeticException;
/**
* Returns vector entries as a T array.
* @return T array of entries
* @deprecated as of 3.1, to be removed in 4.0. Please use the {@link #toArray()} method instead.
*/
@Deprecated
T[] getData();
/**
* Compute the dot product.
* @param v vector with which dot product should be computed
* @return the scalar dot product of {@code this} and {@code v}
* @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
*/
T dotProduct(FieldVector<T> v) throws DimensionMismatchException;
/**
* Find the orthogonal projection of this vector onto another vector.
* @param v vector onto which {@code this} must be projected
* @return projection of {@code this} onto {@code v}
* @throws DimensionMismatchException if {@code v} is not the same size as {@code this}
* @throws MathArithmeticException if {@code v} is the null vector.
*/
FieldVector<T> projection(FieldVector<T> v)
throws DimensionMismatchException, MathArithmeticException;
/**
* Compute the outer product.
* @param v vector with which outer product should be computed
* @return the matrix outer product between instance and v
*/
FieldMatrix<T> outerProduct(FieldVector<T> v);
/**
* Returns the entry in the specified index.
*
* @param index Index location of entry to be fetched.
* @return the vector entry at {@code index}.
* @throws OutOfRangeException if the index is not valid.
* @see #setEntry(int, FieldElement)
*/
T getEntry(int index) throws OutOfRangeException;
/**
* Set a single element.
* @param index element index.
* @param value new value for the element.
* @throws OutOfRangeException if the index is not valid.
* @see #getEntry(int)
*/
void setEntry(int index, T value) throws OutOfRangeException;
/**
* Returns the size of the vector.
* @return size
*/
int getDimension();
/**
* Construct a vector by appending a vector to this vector.
* @param v vector to append to this one.
* @return a new vector
*/
FieldVector<T> append(FieldVector<T> v);
/**
* Construct a vector by appending a T to this vector.
* @param d T to append.
* @return a new vector
*/
FieldVector<T> append(T d);
/**
* Get a subvector from consecutive elements.
* @param index index of first element.
* @param n number of elements to be retrieved.
* @return a vector containing n elements.
* @throws OutOfRangeException if the index is not valid.
* @throws NotPositiveException if the number of elements if not positive.
*/
FieldVector<T> getSubVector(int index, int n)
throws OutOfRangeException, NotPositiveException;
/**
* Set a set of consecutive elements.
* @param index index of first element to be set.
* @param v vector containing the values to set.
* @throws OutOfRangeException if the index is not valid.
*/
void setSubVector(int index, FieldVector<T> v) throws OutOfRangeException;
/**
* Set all elements to a single value.
* @param value single value to set for all elements
*/
void set(T value);
/**
* Convert the vector to a T array.
* <p>The array is independent from vector data, it's elements
* are copied.</p>
* @return array containing a copy of vector elements
*/
T[] toArray();
}