Vector of polynomial coefficients, listed in
increasing order (by index; see details below).
type
"matrix" or "ddmatrix".
...
Additional arguments.
bldim
blocking dimension.
ICTXT
BLACS context number.
Value
Returns a matrix or a distributed matrix.
Details
For a degree n polynomial,
$x^n + a_{n-1}x^{n-1} + \dots + a_1x + a_0$
its associated companion matrix is a matrix of the form
$\left[\begin{array}{cccccc}
0 & 0 & 0 & \dots & 0 & -a_0\
1 & 0 & 0 & \dots & 0 & -a_1\
0 & 1 & 0 & \dots & 0 & -a_2\
\vdots & \vdots & \vdots & \ddots & \vdots & \vdots\
0 & 0 & 0 & \dots & 1 & -a_{n-1}
\end{array}\right]$
In the function call, we assume that the argument 'coef'
is ordered from $a_0$ to $a_{n-1}$.
NOTE that we assume that the leading coefficient is 1.