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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)
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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)))
See also topics 'complex_data', cmplx(), creal() and polyroot().
Gary Oehlert
2003-01-15