From: Michael Povolotskyi <povolotskyi@in...>  20051214 18:22:29

<!DOCTYPE html PUBLIC "//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO88591" httpequiv="ContentType"> <title></title> </head> <body bgcolor="#cccccc" text="#000000"> 1) Yes, I mean Hx = gSx, sorry for the error.<br> 2) Does it mean that if one wants to use Libmesh just for one complex problem, then all the other problems also have to be complex? <br> <br> thank you,<br> Michael.<br> <br> <br> <br> Roy Stogner wrote: <blockquote cite="midPine.LNX.4.63.0512141154180.4247@..." type="cite">On Wed, 14 Dec 2005, Michael Povolotskyi wrote: <br> <br> <blockquote type="cite">I have to solve an eigenvalue problem for a quantum physics calculations. <br> My questions are: <br> 1) Is it possible to solve a general eigenvalue problem like Hx = Sx, <br> where H and S are known matrixes. <br> </blockquote> <br> Are you sure you don't mean Hx = gSx, where H and S are known but g is <br> unknown? That's the generalized eigenvalue problem built into SLEPc, <br> which is currently the only eigenvalue solve libMesh interfaces with. <br> Our SLEPc support currently only handles the simple Hx = gx problem, <br> and a new interface would have to be written to get generalized <br> eigenvalues. <br> <br> <blockquote type="cite">2) Is it possible to have complex (selfconjugated) matrixes? <br> </blockquote> <br> If both PETSc and libMesh have been compiled with complex number <br> support on, then the default PetscScalar and libMesh Number types will <br> both be std::complex<double>, and PETSc should handle the linear <br> algebra appropriately. All my code is realvalued, though; I'm not <br> sure who's keeping the libMesh complex number support up to date. <br>  <br> Roy Stogner <br> <br> </blockquote> <br> <br> <pre class="mozsignature" cols="250">  Michael Povolotskyi, Ph.D. University of Rome "Tor Vergata" Department of Electronic Engineering Viale Politecnico, 1  00133 Rome  Italy Phone + 39 06 72597781 Fax + 39 06 2020519 <a class="moztxtlinkfreetext" href="http://www.optolab.uniroma2.it/pages/moshe/moshe.html">http://www.optolab.uniroma2.it/pages/moshe/moshe.html</a>;  </pre> </body> </html> 