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# evalpoly()

Usage:
 ```evalpoly(coef,z), coef and z REAL matrices with ncols(z)=2*ncols(coef) evalpoly(coef,z,T), coef and z REAL matrices with ncols(z)=ncols(coef) ```

Keywords:
```evalpoly(coef,z) evaluates polynomials with REAL coefficients in coef
for complex arguments specified by z.

Specifically, when coef is a n by p REAL matrix and z is a N by 2*p
REAL matrix considered as representing a N by p complex matrix Z,
evalpoly(coef,z) evaluates
Z^n - coefs[1,]*Z^(n-1) - ... - coef[n-1,]*Z - coef[n,],

The result is a N by 2*p REAL matrix representing a N by p complex
matrix.

By definition, evalpoly(coef,polyroot(coef)) should be zero within
rounding error.

It is an error when ncols(z) != 2*ncols(coef).

evalpoly(coef,x,T) does the same except x is considered to be a real
rather than complex matrix with ncols(x) = ncols(coef).  The result
is a matrix with the same dimensions as x and is the same as
creal(evalpoly(coef,cmplx(x)))