trh@ukc.UUCP (T.R.Hopkins) (05/15/85)
> >This is further info. on the diagonalization routine I requested: > >The matrix is real and tri-diagonal, unfortunately Idon't think its >hermetian but that shouldnt affect the diagonalization routine. > >I'm trying to simulate atoms in a laser cavity so N will be greater than >500 hopefully larger. > >I hope someone has an efficient routine to run on a VAX, > >Thanks, > >Ed Dougherty > >allegra ! psuvax ! burdvax !edwardd > > In efficiency terms it makes a lot of difference whether i) the matrix is symmetric ii) you want all the eigenvalues or <25% of them iii) you want any of the associated eigenvectors a good source of algorithms (in ALGOL 60) is Wilkinson & Reinsch `Handbook for Automatic Computation volume II Linear Algebra'. Alternatively (if you're willing to stoop as low as f77) there is the public domain package EISPACK - which we implemented without any changes to the source on our VAX. Tim Hopkins, Computing Laboratory, University of Kent, Canterbury CT2 7NF Kent U.K. { trh@ukc.UUCP }