Examples with Array2DRowRealMatrix org.hipparchus.linear.Array2DRowRealMatrix used on opensource projects

Example 1 with Array2DRowRealMatrix

use of org.hipparchus.linear.Array2DRowRealMatrix in project symja_android_library by axkr.

the class Roots method findRoots.

/**
	 * <p>
	 * Given a set of polynomial coefficients, compute the roots of the
	 * polynomial. Depending on the polynomial being considered the roots may
	 * contain complex number. When complex numbers are present they will come
	 * in pairs of complex conjugates.
	 * </p>
	 * 
	 * @param coefficients
	 *            coefficients of the polynomial.
	 * @return the roots of the polynomial
	 */
@Nonnull
public static IAST findRoots(double... coefficients) {
    int N = coefficients.length - 1;
    // Construct the companion matrix
    RealMatrix c = new Array2DRowRealMatrix(N, N);
    double a = coefficients[N];
    for (int i = 0; i < N; i++) {
        c.setEntry(i, N - 1, -coefficients[i] / a);
    }
    for (int i = 1; i < N; i++) {
        c.setEntry(i, i - 1, 1);
    }
    try {
        IAST roots = F.List();
        EigenDecomposition ed = new EigenDecomposition(c);
        double[] realValues = ed.getRealEigenvalues();
        double[] imagValues = ed.getImagEigenvalues();
        for (int i = 0; i < N; i++) {
            roots.append(F.chopExpr(F.complexNum(realValues[i], imagValues[i]), Config.DEFAULT_ROOTS_CHOP_DELTA));
        }
        return roots;
    } catch (Exception ime) {
        throw new WrappedException(ime);
    }
}

Example 2 with Array2DRowRealMatrix

use of org.hipparchus.linear.Array2DRowRealMatrix in project symja_android_library by axkr.

the class Convert method list2RealMatrix.

/**
	 * Returns a RealMatrix if possible.
	 * 
	 * @param listMatrix
	 * @return a RealMatrix or <code>null</code> if the given list is no matrix.
	 * @throws WrongArgumentType
	 *             if not all elements are convertable to a <code>double</code>
	 *             value.
	 * @throws ClassCastException
	 * @throws IndexOutOfBoundsException
	 * @deprecated use {@link IExpr#toRealMatrix()}
	 */
public static RealMatrix list2RealMatrix(final IAST listMatrix) throws ClassCastException, IndexOutOfBoundsException {
    if (listMatrix == null) {
        return null;
    }
    if (listMatrix instanceof ASTRealMatrix) {
        return ((ASTRealMatrix) listMatrix).getRealMatrix();
    }
    final Object header = listMatrix.head();
    if (header != F.List) {
        return null;
    }
    IAST currInRow = (IAST) listMatrix.arg1();
    if (currInRow.isAST0()) {
        // special case 0-Matrix
        double[][] array = new double[0][0];
        return new Array2DRowRealMatrix(array, false);
    }
    final double[][] elements = Expr2Object.toDoubleMatrix(listMatrix);
    return new Array2DRowRealMatrix(elements, false);
}