小编典典

请找到以下相同的示例示例

public class PolynomialRootFinder {

/**

*

* 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.

*

*

* @param coefficients Coefficients of the polynomial.

* @return The roots of the polynomial

*/

public static Complex64F[] findRoots(double... coefficients) {

int N = coefficients.length-1;

// Construct the companion matrix

DenseMatrix64F c = new DenseMatrix64F(N,N);

double a = coefficients[N];

for( int i = 0; i < N; i++ ) {

c.set(i,N-1,-coefficients[i]/a);

}

for( int i = 1; i < N; i++ ) {

c.set(i,i-1,1);

}

// use generalized eigenvalue decomposition to find the roots

EigenDecomposition evd = DecompositionFactory.eigGeneral(N, false);

evd.decompose(c);

Complex64F[] roots = new Complex64F[N];

for( int i = 0; i < N; i++ ) {

roots[i] = evd.getEigenvalue(i);

}

return roots;

}

}

2020-11-19