# polymroot¶

## Purpose¶

Computes the roots of the determinant of a matrix polynomial.

## Format¶

r = polymroot(c)
Parameters

c (matrix) – (N+1)*KxK matrix. coefficients of an Nth order polynomial of rank K

Returns

r (K*N vector) – contains the roots of the determinantal equation.

## Examples¶

Solve

$det(A2*t^2 + A1*t + A0) = 0$

where

A2 =  1  2    A1 =  5  8   A0 = 3  4
2  1         10  7        6  5

// Setup coefficient matrices
a2 = { 1 2, 2 1 };
a1 = { 5 8, 10 7 };
a0 = { 3 4, 6 5 };

// The pipe operator '|' provides vertical concatenation
print  polymroot(a2|a1|a0);

-4.3027756
-.69722436
-2.6180340
-.38196601


## Remarks¶

c is constructed of N+1 KxK coefficient matrices stacked vertically with the coefficient matrix of the $$t^n$$ at the top, $$t^{n-1}$$ next, down to the $$t^0$$ matrix at the bottom.

Note that this procedure solves the scalar problem as well, that is, the one that polyroot() solves.