# DSSetFN

Sets a number of functions to be used internally by DS.

### Synopsis

    #include "slepcds.h"
    PetscErrorCode DSSetFN(DS ds,PetscInt n,FN f[])

Collective on DS and FN

### Input Parameters

| ds | - the direct solver context
| n | - number of functions
| f | - array of functions

### Notes

In the basic usage, only one function is used, for instance to evaluate a function of the projected matrix. In the context of nonlinear eigensolvers, there are as many functions as terms in the split nonlinear operator T(lambda) = sum_i A_i*f_i(lambda).

This function must be called before DSAllocate(). Then DSAllocate() will allocate an extra matrix per each function.

### See Also

DSGetFN(), DSGetFN(), DSAllocate()

Location: src/ds/interface/dsbasic.c
Index of all DS routines
Table of Contents for all manual pages
Index of all manual pages