/*
Copyright (C) 1999 CERN - European Organization for Nuclear Research.
Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose 
is hereby granted without fee, provided that the above copyright notice appear in all copies and 
that both that copyright notice and this permission notice appear in supporting documentation. 
CERN makes no representations about the suitability of this software for any purpose. 
It is provided "as is" without expressed or implied warranty.
 */
package cern.colt.matrix.tdcomplex;

import java.util.ArrayList;

import cern.colt.matrix.tdcomplex.impl.DenseDComplexMatrix1D;
import cern.colt.matrix.tdcomplex.impl.SparseDComplexMatrix1D;

/**
 * Factory for convenient construction of 1-d matrices holding complex
 * cells. Use idioms like ComplexFactory1D.dense.make(1000) to
 * construct dense matrices, ComplexFactory1D.sparse.make(1000) to
 * construct sparse matrices.
 * 
 * If the factory is used frequently it might be useful to streamline the
 * notation. For example by aliasing:
 * 
 * 
 * 

 * 
 * 
 *  ComplexFactory1D F = ComplexFactory1D.dense;
 *  F.make(1000);
 *  F.random(3);
 *  ...
 * 
 * 
 * 
 * 
 * @author Piotr Wendykier (piotr.wendykier@gmail.com)
 */
public class DComplexFactory1D extends cern.colt.PersistentObject {
    private static final long serialVersionUID = 1L;

    /**
     * A factory producing dense matrices.
     */
    public static final DComplexFactory1D dense = new DComplexFactory1D();

    /**
     * A factory producing sparse matrices.
     */
    public static final DComplexFactory1D sparse = new DComplexFactory1D();

    /**
     * Makes this class non instantiable, but still let's others inherit from
     * it.
     */
    protected DComplexFactory1D() {
    }

    /**
     * C = A||B; Constructs a new matrix which is the concatenation of two other
     * matrices. Example: 0 1 append 3 4 --> 0 1 3 4.
     */
    public DComplexMatrix1D append(DComplexMatrix1D A, DComplexMatrix1D B) {
        // concatenate
        DComplexMatrix1D matrix = make((int) (A.size() + B.size()));
        matrix.viewPart(0, (int) A.size()).assign(A);
        matrix.viewPart((int) A.size(), (int) B.size()).assign(B);
        return matrix;
    }

    /**
     * Constructs a matrix with the given cell values. The values are copied. So
     * subsequent changes in values are not reflected in the matrix,
     * and vice-versa.
     * 
     * @param values
     *            The values to be filled into the new matrix.
     */
    public DComplexMatrix1D make(double[] values) {
        if (this == sparse)
            return new SparseDComplexMatrix1D(values);
        else
            return new DenseDComplexMatrix1D(values);
    }

    /**
     * Constructs a matrix which is the concatenation of all given parts. Cells
     * are copied.
     */
    public DComplexMatrix1D make(DComplexMatrix1D[] parts) {
        if (parts.length == 0)
            return make(0);

        int size = 0;
        for (int i = 0; i < parts.length; i++)
            size += parts[i].size();

        DComplexMatrix1D vector = make(size);
        size = 0;
        for (int i = 0; i < parts.length; i++) {
            vector.viewPart(size, (int) parts[i].size()).assign(parts[i]);
            size += parts[i].size();
        }

        return vector;
    }

    /**
     * Constructs a matrix with the given shape, each cell initialized with
     * zero.
     */
    public DComplexMatrix1D make(int size) {
        if (this == sparse) {
            return new SparseDComplexMatrix1D(size);
        } else {
            return new DenseDComplexMatrix1D(size);
        }
    }

    /**
     * Constructs a matrix with the given shape, each cell initialized with the
     * given value.
     */
    public DComplexMatrix1D make(int size, double[] initialValue) {
        return make(size).assign(initialValue[0], initialValue[1]);
    }

    /**
     * Constructs a matrix from the values of the given list. The values are
     * copied. So subsequent changes in values are not reflected in the
     * matrix, and vice-versa.
     * 
     * @param values
     *            The values to be filled into the new matrix.
     * @return a new matrix.
     */
    public DComplexMatrix1D make(ArrayList values) {
        int size = values.size();
        DComplexMatrix1D vector = make(size);
        for (int i = 0; i < size; i++)
            vector.setQuick(i, values.get(i));
        return vector;
    }

    /**
     * Constructs a matrix with uniformly distributed values in (0,1)
     * (exclusive).
     */
    public DComplexMatrix1D random(int size) {
        return make(size).assign(cern.jet.math.tdcomplex.DComplexFunctions.random());
    }

    /**
     * C = A||A||..||A; Constructs a new matrix which is concatenated
     * repeat times.
     */
    public DComplexMatrix1D repeat(DComplexMatrix1D A, int repeat) {
        int size = (int) A.size();
        DComplexMatrix1D matrix = make(repeat * size);
        for (int i = 0; i < repeat; i++) {
            matrix.viewPart(size * i, size).assign(A);
        }
        return matrix;
    }

    /**
     * Constructs a randomly sampled matrix with the given shape. Randomly picks
     * exactly Math.round(size*nonZeroFraction) cells and initializes
     * them to value, all the rest will be initialized to zero. Note
     * that this is not the same as setting each cell with probability
     * nonZeroFraction to value.
     * 
     * @throws IllegalArgumentException
     *             if nonZeroFraction < 0 || nonZeroFraction > 1.
     * @see cern.jet.random.tdouble.sampling.DoubleRandomSampler
     */
    public DComplexMatrix1D sample(int size, double[] value, double nonZeroFraction) {
        double epsilon = 1e-09;
        if (nonZeroFraction < 0 - epsilon || nonZeroFraction > 1 + epsilon)
            throw new IllegalArgumentException();
        if (nonZeroFraction < 0)
            nonZeroFraction = 0;
        if (nonZeroFraction > 1)
            nonZeroFraction = 1;

        DComplexMatrix1D matrix = make(size);

        int n = (int) Math.round(size * nonZeroFraction);
        if (n == 0)
            return matrix;

        cern.jet.random.tdouble.sampling.DoubleRandomSamplingAssistant sampler = new cern.jet.random.tdouble.sampling.DoubleRandomSamplingAssistant(
                n, size, new cern.jet.random.tdouble.engine.DoubleMersenneTwister());
        for (int i = 0; i < size; i++) {
            if (sampler.sampleNextElement()) {
                matrix.setQuick(i, value);
            }
        }

        return matrix;
    }

    /**
     * Constructs a list from the given matrix. The values are copied. So
     * subsequent changes in values are not reflected in the list, and
     * vice-versa.
     * 
     * @param values
     *            The values to be filled into the new list.
     * @return a new list.
     */
    public ArrayList toList(DComplexMatrix1D values) {
        int size = (int) values.size();
        ArrayList list = new ArrayList(size);
        for (int i = 0; i < size; i++)
            list.set(i, values.getQuick(i));
        return list;
    }
}