// --- BEGIN LICENSE BLOCK ---
/* 
 * Copyright (c) 2009, Mikio L. Braun
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 *     * Redistributions of source code must retain the above copyright
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 * 
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 * 
 *     * Neither the name of the Technische Universität Berlin nor the
 *       names of its contributors may be used to endorse or promote
 *       products derived from this software without specific prior
 *       written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// --- END LICENSE BLOCK ---

package org.jblas;

import org.junit.Test;

import static org.jblas.MatrixFunctions.abs;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

public class TestBlasFloat {

  /**
   * test sum of absolute values
   */
  @Test
  public void testAsum() {
    float[] a = new float[]{1.0f, 2.0f, 3.0f, 4.0f};

    assertEquals(10.0f, NativeBlas.sasum(4, a, 0, 1), 1e-6);
    assertEquals(4.0f, NativeBlas.sasum(2, a, 0, 2), 1e-6);
    assertEquals(5.0f, NativeBlas.sasum(2, a, 1, 1), 1e-6);
  }

  /**
   * test scalar product
   */
  @Test
  public void testDot() {
    float[] a = new float[]{1.0f, 2.0f, 3.0f, 4.0f};
    float[] b = new float[]{4.0f, 5.0f, 6.0f, 7.0f};

    assertEquals(32.0f, NativeBlas.sdot(3, a, 0, 1, b, 0, 1), 1e-6);
    assertEquals(22.0f, NativeBlas.sdot(2, a, 0, 2, b, 0, 2), 1e-6);
    assertEquals(5.0f + 12.0f + 21.0f, NativeBlas.sdot(3, a, 0, 1, b, 1, 1), 1e-6);
  }

  @Test
  public void testSwap() {
    float[] a = new float[]{1.0f, 2.0f, 3.0f, 4.0f};
    float[] b = new float[]{4.0f, 5.0f, 6.0f, 7.0f};
    float[] c = new float[]{1.0f, 2.0f, 3.0f, 4.0f};
    float[] d = new float[]{4.0f, 5.0f, 6.0f, 7.0f};

    NativeBlas.sswap(4, a, 0, 1, b, 0, 1);
    assertTrue(arraysEqual(a, d));
    assertTrue(arraysEqual(b, c));

    NativeBlas.sswap(2, a, 0, 2, a, 1, 2);
    assertTrue(arraysEqual(a, 5.0f, 4.0f, 7.0f, 6.0f));
  }

  /* test vector addition */
  @Test
  public void testAxpy() {
    float[] x = new float[]{1.0f, 2.0f, 3.0f, 4.0f};
    float[] y = new float[]{0.0f, 0.0f, 0.0f, 0.0f};

    NativeBlas.saxpy(4, 2.0f, x, 0, 1, y, 0, 1);

    for (int i = 0; i < 4; i++)
      assertEquals(2 * x[i], y[i], 1e-6);
  }

  /* test matric-vector multiplication */
  @Test
  public void testGemv() {
    float[] A = new float[]{1.0f, 2.0f, 3.0f,
        4.0f, 5.0f, 6.0f,
        7.0f, 8.0f, 9.0f};

    float[] x = new float[]{1.0f, 3.0f, 7.0f};
    float[] y = new float[]{0.0f, 0.0f, 0.0f};

    NativeBlas.sgemv('N', 3, 3, 1.0f, A, 0, 3, x, 0, 1, 0.0f, y, 0, 1);

    //printMatrix(3, 3, A);
    //printMatrix(3, 1, x);
    //printMatrix(3, 1, y);

    assertTrue(arraysEqual(y, 62.0f, 73.0f, 84.0f));

    NativeBlas.sgemv('T', 3, 3, 1.0f, A, 0, 3, x, 0, 1, 0.5f, y, 0, 1);

    //printMatrix(3, 1, y);
    assertTrue(arraysEqual(y, 59.0f, 97.5f, 136.0f));
  }

  /**
   * Compare float buffer against an array of floats
   */
  private boolean arraysEqual(float[] a, float... b) {
    if (a.length != b.length)
      return false;
    else {
      float diff = 0.0f;
      for (int i = 0; i < b.length; i++)
        diff += abs(a[i] - b[i]);
      return diff < 1e-6 * a.length;
    }
  }

  @Test
  public void testSolve() {
    FloatMatrix A = new FloatMatrix(3, 3, 3.0f, 5.0f, 6.0f, 1.0f, 0.0f, 0.0f, 2.0f, 4.0f, 0.0f);
    FloatMatrix X = new FloatMatrix(3, 1, 1.0f, 2.0f, 3.0f);
    int[] p = new int[3];
    SimpleBlas.gesv(A, p, X);
    //A.print();
    //X.print();

    // De-shuffle X
    for (int i = 2; i >= 0; i--) {
      int perm = p[i] - 1;
      float t = X.get(i);
      X.put(i, X.get(perm));
      X.put(perm, t);
    }

    //X.print();
    assertTrue(arraysEqual(X.data, -0.25f, -0.125f, 0.5f));
  }

  @Test
  public void testSymmetricSolve() {
    //System.out.println("--- Symmetric solve");
    FloatMatrix A = new FloatMatrix(3, 3, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f);
    FloatMatrix x = new FloatMatrix(3, 1, 1.0f, 2.0f, 3.0f);
    int[] p = new int[3];
    SimpleBlas.sysv('U', A, p, x);
    //A.print();
    //x.print();
    assertTrue(arraysEqual(x.data, 0.3f, 0.0f, 0.1f));
  }

  @Test
  public void testSYEV() {
    /* From R:
        > x <- matrix(c(1,0.5f,0.1f,0.5f,1.0f, 0.5f, 0.1f, 0.5f, 1.0f), 3, 3)
        > eigen(x)
        $values
        [1] 1.7588723f 0.9000000f 0.3411277f

        $vectors
                   [,1]          [,2]       [,3]
        [1,] -0.5173332f -7.071068e-01f  0.4820439f
        [2,] -0.6817131f -7.182297e-16f -0.7316196f
        [3,] -0.5173332f  7.071068e-01f  0.4820439f
    */

    FloatMatrix A = new FloatMatrix(new float[][]{{1.0f, 0.5f, 0.1f}, {0.5f, 1.0f, 0.5f}, {0.1f, 0.5f, 1.0f}});
    FloatMatrix w = new FloatMatrix(3);

    FloatMatrix B = A.dup();
    SimpleBlas.syev('V', 'U', B, w);

    assertTrue(arraysEqual(w.data, 0.34112765606210876f, 0.9f, 1.7588723439378915f));
    assertTrue(arraysEqual(B.data, -0.48204393949466345f, 0.731619628490741f, -0.482043939494664f, -0.7071067811865474f, 1.3877787807814457E-16f, 0.707106781186547f, 0.5173332005549852f, 0.6817130768931094f, 0.5173332005549856f));

    B = A.dup();
    SimpleBlas.syevd('V', 'U', B, w);

    assertTrue(arraysEqual(w.data, 0.34112765606210876f, 0.9f, 1.7588723439378915f));
    assertTrue(arraysEqual(B.data, -0.48204393949466345f, 0.731619628490741f, -0.482043939494664f, -0.7071067811865474f, 1.3877787807814457E-16f, 0.707106781186547f, 0.5173332005549852f, 0.6817130768931094f, 0.5173332005549856f));
  }
}