polychar#

Purpose#

Computes the characteristic polynomial of a square matrix.

c = polychar(x)#

Parameters:

x (NxN matrix) – data.

Returns:

c ((N+1)x1 vector) –

coefficients of the Nth order characteristic polynomial of x:

\[p(x) = c[1]*x^n + c[2]*x^{(n-1)} + ... + c[n]*x + c[n+1];\]

The coefficient of \(x^n\) is set to unity (\(c[1]=1\)).

x = { 2 1, 1 2 };

// Compute the characteristic polynomial
c = polychar(x);
print c;

The code above produces the following output:

 1.0000000
-4.0000000
 3.0000000

This represents the polynomial \(p(\lambda) = \lambda^2 - 4\lambda + 3\).

poly.src