FNSetScale#

Sets the scaling parameters that define the matematical function.

Synopsis#

#include "slepcfn.h" 
PetscErrorCode FNSetScale(FN fn,PetscScalar alpha,PetscScalar beta)

Logically Collective

Input Parameters#

fn - the math function context
alpha - inner scaling (argument)
beta - outer scaling (result)

Notes#

Given a function \(f(x)\) specified by the FN type, the scaling parameters can be used to realize the function \(\beta f(\alpha x)\). So when these values are given, the procedure for function evaluation will first multiply the argument by \(\alpha\), then evaluate the function itself, and finally scale the result by \(\beta\). Likewise, these values are also considered when evaluating the derivative.

If you want to provide only one of the two scaling factors, set the other one to 1.0.