cern.colt.matrix.tfcomplex.FComplexFactory1D Maven / Gradle / Ivy

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Parallel Colt is a multithreaded version of Colt - a library for high performance scientific computing in Java. It contains efficient algorithms for data analysis, linear algebra, multi-dimensional arrays, Fourier transforms, statistics and histogramming.
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/*
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.tfcomplex;

import java.util.ArrayList;

import cern.colt.matrix.tfcomplex.impl.DenseFComplexMatrix1D;
import cern.colt.matrix.tfcomplex.impl.SparseFComplexMatrix1D;

/**
 * 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 ([email protected])
 */
public class FComplexFactory1D extends cern.colt.PersistentObject {
    private static final long serialVersionUID = 1L;

    /**
     * A factory producing dense matrices.
     */
    public static final FComplexFactory1D dense = new FComplexFactory1D();

    /**
     * A factory producing sparse matrices.
     */
    public static final FComplexFactory1D sparse = new FComplexFactory1D();

    /**
     * Makes this class non instantiable, but still let's others inherit from
     * it.
     */
    protected FComplexFactory1D() {
    }

    /**
     * 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 FComplexMatrix1D append(FComplexMatrix1D A, FComplexMatrix1D B) {
        // concatenate
        FComplexMatrix1D 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 FComplexMatrix1D make(float[] values) {
        if (this == sparse)
            return new SparseFComplexMatrix1D(values);
        else
            return new DenseFComplexMatrix1D(values);
    }

    /**
     * Constructs a matrix which is the concatenation of all given parts. Cells
     * are copied.
     */
    public FComplexMatrix1D make(FComplexMatrix1D[] parts) {
        if (parts.length == 0)
            return make(0);

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

        FComplexMatrix1D 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 FComplexMatrix1D make(int size) {
        if (this == sparse) {
            return new SparseFComplexMatrix1D(size);
        } else {
            return new DenseFComplexMatrix1D(size);
        }
    }

    /**
     * Constructs a matrix with the given shape, each cell initialized with the
     * given value.
     */
    public FComplexMatrix1D make(int size, float[] 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 FComplexMatrix1D make(ArrayList values) {
        int size = values.size();
        FComplexMatrix1D 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 FComplexMatrix1D random(int size) {
        return make(size).assign(cern.jet.math.tfcomplex.FComplexFunctions.random());
    }

    /**
     * C = A||A||..||A; Constructs a new matrix which is concatenated
     * repeat times.
     */
    public FComplexMatrix1D repeat(FComplexMatrix1D A, int repeat) {
        int size = (int) A.size();
        FComplexMatrix1D 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.tfloat.sampling.FloatRandomSampler
     */
    public FComplexMatrix1D sample(int size, float[] value, float nonZeroFraction) {
        float epsilon = 1e-05f;
        if (nonZeroFraction < 0 - epsilon || nonZeroFraction > 1 + epsilon)
            throw new IllegalArgumentException();
        if (nonZeroFraction < 0)
            nonZeroFraction = 0;
        if (nonZeroFraction > 1)
            nonZeroFraction = 1;

        FComplexMatrix1D matrix = make(size);

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

        cern.jet.random.tfloat.sampling.FloatRandomSamplingAssistant sampler = new cern.jet.random.tfloat.sampling.FloatRandomSamplingAssistant(
                n, size, new cern.jet.random.tfloat.engine.FloatMersenneTwister());
        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(FComplexMatrix1D 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;
    }
}