# Complex polynomial eigenvalue problem with Morley elements using SLEPc

**URL:** <https://community.freefem.org/t/complex-polynomial-eigenvalue-problem-with-morley-elements-using-slepc/651>\
**Category:** General Discussion\
**Created:** [November 12, 2020, 4:17pm UTC](https://community.freefem.org/t/complex-polynomial-eigenvalue-problem-with-morley-elements-using-slepc/651 "2020-11-12T16:17:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![AntoniJ](https://avatars.discourse-cdn.com/v4/letter/a/f04885/32.png) [@AntoniJ](https://community.freefem.org/u/AntoniJ)\
**Post date:** [November 12, 2020, 4:17pm UTC](https://community.freefem.org/t/complex-polynomial-eigenvalue-problem-with-morley-elements-using-slepc/651/1 "2020-11-12T16:17:56Z")

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Dear developers,  
I am trying to use SLEPc to solve a complex polynomial eigenvalue problem with a sequential program (I don’t need to parallelize it yet) and the command PEPSolve doesn’t seem to be implemented, at least for me. I can run all the examples using EPSSolve as well as the only example using NEPSolve but when I try to use the polynomial eigenproblem solver this error occurs: “The Identifier PEPSolve does not exist”

Part of the reason I don’t want a parallel program is because I use Morley elements, I am working on a plate bending problem. And the script “macro\_ddm.idp” called in these examples doesn’t seem to be adapted to this element (the size of the eigenvectors is 3).

I also tried to solve my problem with the nonlinear solver NEPSolve using the example “nonlinear-2d-SLEPc-complex.edp”. I attempted to turn this parallel program into a sequential program, in vain. I am new to parallel computation and unlike the linear examples this one doesn’t perform any geometric domain decomposition so I am a bit lost.

Do you have any idea to solve my problem?  
Thank you.  
Antoni

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**Author:** ![prj](https://avatars.discourse-cdn.com/v4/letter/p/ecae2f/32.png) [@prj](https://community.freefem.org/u/prj)\
**Post date:** [November 12, 2020, 7:00pm UTC](https://community.freefem.org/t/complex-polynomial-eigenvalue-problem-with-morley-elements-using-slepc/651/2 "2020-11-12T19:00:09Z")

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Dear Antoni,

1. I’ve put a [new parallel example](https://github.com/FreeFem/FreeFem-sources/blob/develop/examples/hpddm/bilaplace-2d-PETSc.edp) in the distribution that uses Morley elements (as a general rule of thumb, for your own safety, it’s best not to look at `macro_ddm.idp`)
2. `PEPSolve` is not interfaced yet, because no one asked me about it. If you need it, I can definitely hook it up

I’ll reach out to you in private to see how to move forward (`NEPSolve` should not be used if your problem is indeed polynomial).