@Test(expectedExceptions = IllegalArgumentException.class) public void testDivideNull() { F1.divide(null); }
/** * Gets the polynomials. * * @param n the n value * @param alpha the alpha value * @return the result */ public DoubleFunction1D[] getPolynomials(int n, double alpha) { ArgChecker.isTrue(n >= 0); DoubleFunction1D[] polynomials = new DoubleFunction1D[n + 1]; for (int i = 0; i <= n; i++) { if (i == 0) { polynomials[i] = getOne(); } else if (i == 1) { polynomials[i] = new RealPolynomialFunction1D(new double[] {1 + alpha, -1}); } else { polynomials[i] = (polynomials[i - 1].multiply(2. * i + alpha - 1).subtract(polynomials[i - 1].multiply(getX())) .subtract(polynomials[i - 2].multiply((i - 1. + alpha))).divide(i)); } } return polynomials; }
/** * Gets the polynomials and derivative. * * @param n the n value * @param alpha the alpha value * @return the result */ public Pair<DoubleFunction1D, DoubleFunction1D>[] getPolynomialsAndFirstDerivative(int n, double alpha) { ArgChecker.isTrue(n >= 0); @SuppressWarnings("unchecked") Pair<DoubleFunction1D, DoubleFunction1D>[] polynomials = new Pair[n + 1]; DoubleFunction1D p, dp, p1, p2; for (int i = 0; i <= n; i++) { if (i == 0) { polynomials[i] = Pair.of(getOne(), getZero()); } else if (i == 1) { polynomials[i] = Pair.of(F1, DF1); } else { p1 = polynomials[i - 1].getFirst(); p2 = polynomials[i - 2].getFirst(); p = (p1.multiply(2. * i + alpha - 1).subtract(p1.multiply(getX())).subtract(p2.multiply((i - 1. + alpha))).divide(i)); dp = (p.multiply(i).subtract(p1.multiply(i + alpha))).divide(getX()); polynomials[i] = Pair.of(p, dp); } } return polynomials; }
/** * Calculates polynomials. * @param n the n value * @param alpha the alpha value * @param beta the beta value * @return the result */ public DoubleFunction1D[] getPolynomials(int n, double alpha, double beta) { ArgChecker.isTrue(n >= 0); DoubleFunction1D[] polynomials = new DoubleFunction1D[n + 1]; for (int i = 0; i <= n; i++) { if (i == 0) { polynomials[i] = getOne(); } else if (i == 1) { polynomials[i] = new RealPolynomialFunction1D(new double[] {(alpha - beta) / 2, (alpha + beta + 2) / 2}); } else { int j = i - 1; polynomials[i] = (polynomials[j].multiply(getB(alpha, beta, j)).add(polynomials[j].multiply(getX()).multiply(getC(alpha, beta, j)) .add(polynomials[j - 1].multiply(getD(alpha, beta, j))))) .divide(getA(alpha, beta, j)); } } return polynomials; }
DoubleFunction1D temp2 = p1.multiply(getX()).multiply(getC(alpha, beta, j)); DoubleFunction1D temp3 = p2.multiply(getD(alpha, beta, j)); p = (temp1.add(temp2).add(temp3)).divide(getA(alpha, beta, j)); dp = p.derivative(); polynomials[i] = Pair.of(p, dp);