Example usage for org.apache.mahout.math.function Functions random

Introduction

In this page you can find the example usage for org.apache.mahout.math.function Functions random.

Prototype

public static DoubleFunction random() 

Source Link

Document

Constructs a function that returns a new uniform random number in the open unit interval (0.0,1.0) (excluding 0.0 and 1.0).

Usage

From source file:edu.indiana.d2i.htrc.vecproj.RandomProjection.java

License:Apache License

public RandomProjection(int originalDim /* d */, int reducedDim /* k */) {
    this.originalDim = originalDim;
    this.reducedDim = reducedDim;

    // generate random matrix, use a O(kd) algorithm [Achlioptas, 2000]
    random = Functions.random();
    DoubleFunctionWrapper randomWrapper = new DoubleFunctionWrapper();
    basis = new DenseMatrix(reducedDim, originalDim);
    for (int i = 0; i < reducedDim; i++) {
        DenseVector projection = new DenseVector(originalDim);
        projection.assign(randomWrapper);
        basis.assignRow(i, projection);// w w  w .j a  v a2 s .  com
    }
}

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From source file:edu.indiana.d2i.htrc.vecproj.TestRandomProjection.java

License:Apache License

@Test
public void testProject() {
    long t0 = System.nanoTime();
    random = Functions.random();
    for (int i = 0; i < 100; i++) { // test 100 times
        DenseVector vector = new DenseVector(originalDim);
        vector.assign(random);/*from  w w w. j ava2  s .  c  o  m*/
        Vector projected = projector.project(vector);
        Assert.assertEquals(reducedDim, projected.size());
    }
    long t1 = System.nanoTime();
    System.out.println("elapsed " + ((double) (t1 - t0)) / 1e9);
}

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