# QEPSetScaleFactor

Sets the scaling factor to be used for scaling the quadratic problem before attempting to solve.

### Synopsis

    #include "slepcqep.h"
    PetscErrorCode QEPSetScaleFactor(QEP qep,PetscReal alpha)

Logically Collective on QEP

### Input Parameters

| qep | - the quadratic eigensolver context
| alpha | - the scaling factor

### Options Database Keys

-qep_scale <alpha> - Sets the scaling factor

### Notes

For the problem (l^2*M + l*C + K)*x = 0, the effect of scaling is to work with matrices (alpha^2*M, alpha*C, K), then scale the computed eigenvalue.

The default is to scale with alpha = norm(K)/norm(M).

### See Also

QEPGetScaleFactor()

Location: src/qep/interface/qepopts.c
Index of all QEP routines
Table of Contents for all manual pages
Index of all manual pages