FNRationalSetDenominator#

Sets the parameters defining the denominator of the rational function.

Synopsis#

#include "slepcfn.h" 
PetscErrorCode FNRationalSetDenominator(FN fn,PetscInt nq,PetscScalar qcoeff[])

Logically Collective

Input Parameters#

fn - the math function context
nq - number of coefficients
qcoeff - coefficients (array of scalar values)

Notes#

Let the rational function be \(f(x) = p(x)/q(x)\), where \(p(x)\) and \(q(x)\) are polynomials. This function provides the coefficients of the denominator \(q(x)\). Hence, \(q(x)\) is of degree nq-1. If nq is zero, or this function is not called, then the function is assumed to be polynomial, \(f(x) = p(x)\).

In polynomials, high order coefficients are stored in the first positions of the array, e.g., to represent \(x^2-3\) use {1,0,-3}.