*To*: mathgroup@smc.vnet.net*Subject*: [mg10988] Is there a lowest Eigenvalues function around?*From*: "Christopher R. Carlen" <crobc@epix.net>*Date*: Mon, 16 Feb 1998 03:39:55 -0500*Organization*: epix Internet Services

I have to find the eigenvalues of very large matrices, ie 1024x1024 up to over 10000x10000 . I run out of memory when trying to do more than about 1600x1600 . I know there are algorithms to find the lowest or highest eigenvalues of a matrix, but the Mathematica function Eigenvalues[] finds all of them. Does anyone know if there is an implementation of a lowest-eigenvalues function anywhere? I have looked aroung at www.wolfram.com but didn't find anything. Also, I wonder about memory usage in storing matrices. If a matrix is sparse, does it require less memory to store and manipulate than a not-sparse matrix? Does a matrix with only real values require less memory than a complex matrix? Thanks. -- _______________________ Christopher R. Carlen crobc@epix.net <--- Reply here, please. carlenc@cs.moravian.edu My OS is Linux v2