示例#1
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  /**
   * tests the value of a constant polynomial.
   *
   * <p>value of this is 2.5 everywhere.
   */
  public void testConstants() throws MathException {
    double[] c = {2.5};
    PolynomialFunction f = new PolynomialFunction(c);

    // verify that we are equal to c[0] at several (nonsymmetric) places
    assertEquals(f.value(0.0), c[0], tolerance);
    assertEquals(f.value(-1.0), c[0], tolerance);
    assertEquals(f.value(-123.5), c[0], tolerance);
    assertEquals(f.value(3.0), c[0], tolerance);
    assertEquals(f.value(456.89), c[0], tolerance);

    assertEquals(f.degree(), 0);
    assertEquals(f.derivative().value(0), 0, tolerance);

    assertEquals(f.polynomialDerivative().derivative().value(0), 0, tolerance);
  }
示例#2
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  /** This will test the quintic function f(x) = x^2(x-5)(x+3)(x-1) = x^5 - 3x^4 -13x^3 + 15x^2 */
  public void testQuintic() {
    double[] c = {0.0, 0.0, 15.0, -13.0, -3.0, 1.0};
    PolynomialFunction f = new PolynomialFunction(c);

    // verify that we are equal to c[0] when x=0
    assertEquals(f.value(0.0), c[0], tolerance);

    // now check a few other places
    assertEquals(0.0, f.value(5.0), tolerance);
    assertEquals(0.0, f.value(1.0), tolerance);
    assertEquals(0.0, f.value(-3.0), tolerance);
    assertEquals(54.84375, f.value(-1.5), tolerance);
    assertEquals(-8.06637, f.value(1.3), tolerance);

    assertEquals(f.degree(), 5);
  }
示例#3
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  /**
   * tests the value of a linear polynomial.
   *
   * <p>This will test the function f(x) = 3*x - 1.5
   *
   * <p>This will have the values <tt>f(0.0) = -1.5, f(-1.0) = -4.5, f(-2.5) = -9.0, f(0.5) = 0.0,
   * f(1.5) = 3.0</tt> and <tt>f(3.0) = 7.5</tt>
   */
  public void testLinear() throws MathException {
    double[] c = {-1.5, 3.0};
    PolynomialFunction f = new PolynomialFunction(c);

    // verify that we are equal to c[0] when x=0
    assertEquals(f.value(0.0), c[0], tolerance);

    // now check a few other places
    assertEquals(-4.5, f.value(-1.0), tolerance);
    assertEquals(-9.0, f.value(-2.5), tolerance);
    assertEquals(0.0, f.value(0.5), tolerance);
    assertEquals(3.0, f.value(1.5), tolerance);
    assertEquals(7.5, f.value(3.0), tolerance);

    assertEquals(f.degree(), 1);

    assertEquals(f.polynomialDerivative().derivative().value(0), 0, tolerance);
  }
示例#4
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  /**
   * Tests a second order polynomial.
   *
   * <p>This will test the function f(x) = 2x^2 - 3x -2 = (2x+1)(x-2)
   */
  public void testQuadratic() {
    double[] c = {-2.0, -3.0, 2.0};
    PolynomialFunction f = new PolynomialFunction(c);

    // verify that we are equal to c[0] when x=0
    assertEquals(f.value(0.0), c[0], tolerance);

    // now check a few other places
    assertEquals(0.0, f.value(-0.5), tolerance);
    assertEquals(0.0, f.value(2.0), tolerance);
    assertEquals(-2.0, f.value(1.5), tolerance);
    assertEquals(7.0, f.value(-1.5), tolerance);
    assertEquals(265.5312, f.value(12.34), tolerance);
  }
示例#5
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  /**
   * tests the firstDerivative function by comparison
   *
   * <p>This will test the functions <tt>f(x) = x^3 - 2x^2 + 6x + 3, g(x) = 3x^2 - 4x + 6</tt> and
   * <tt>h(x) = 6x - 4</tt>
   */
  public void testfirstDerivativeComparison() throws MathException {
    double[] f_coeff = {3.0, 6.0, -2.0, 1.0};
    double[] g_coeff = {6.0, -4.0, 3.0};
    double[] h_coeff = {-4.0, 6.0};

    PolynomialFunction f = new PolynomialFunction(f_coeff);
    PolynomialFunction g = new PolynomialFunction(g_coeff);
    PolynomialFunction h = new PolynomialFunction(h_coeff);

    // compare f' = g
    assertEquals(f.derivative().value(0.0), g.value(0.0), tolerance);
    assertEquals(f.derivative().value(1.0), g.value(1.0), tolerance);
    assertEquals(f.derivative().value(100.0), g.value(100.0), tolerance);
    assertEquals(f.derivative().value(4.1), g.value(4.1), tolerance);
    assertEquals(f.derivative().value(-3.25), g.value(-3.25), tolerance);

    // compare g' = h
    assertEquals(g.derivative().value(Math.PI), h.value(Math.PI), tolerance);
    assertEquals(g.derivative().value(Math.E), h.value(Math.E), tolerance);
  }