# Nonlinear Eigenvalue Problem Solver - NEP

The Nonlinear Eigenvalue Problem (NEP) solver is the object provided by SLEPc for specifying an eigenvalue problem that is nonlinear with respect to the eigenvalue (not the eigenvector). This is intended for general nonlinear problems (rather than polynomial eigenproblems) described as T(λ)x= 0.

As in the other solver objects, users can set various options at runtime via the options database (e.g., -nep_nev 4 -nep_type narnoldi). Options can also be set directly in application codes by calling the corresponding routines (e.g., NEPSetDimensions() or NEPSetType()).

Examples

test1.c: Simple 1-D nonlinear eigenproblem.
test2.c: Test NEP interface functions.
test2f.F90: Simple example to test the NEP Fortran interface.
test3.c: Test the SLP solver with a user-provided EPS.
test4.c: Test the RII solver with a user-provided KSP.
test5.c: Test the INTERPOL solver with a user-provided PEP.
test6.c: Test the NArnoldi solver with a user-provided KSP.
test7.c: Test the NLEIGS solver with shell matrices.
test8.c: Test NEP view and monitor functionality.
test9.c: Test the NLEIGS solver with FNCOMBINE.
test10.c: Tests multiple calls to NEPSolve() with different matrix size.
test11.c: Test the CISS solver with the problem of ex22.
test12.c: Test some NLEIGS interface functions.
test13.c: Test the NEPProjectOperator() function.
test14.c: Tests a user-defined convergence test in NEP.
test15.c: Illustrates the use of a user-defined stopping test.
test16.c: Illustrates use of NEPSetEigenvalueComparison().
test17.c: Tests a user-provided preconditioner.