On Mon, Sep 17, 2012 at 5:54 PM, Roy Stogner <[email protected]>wrote:
> Maybe having a > non-positive-definite matrix is the trouble, irrespective of whether > the matrix is actually indefinite or not? > Stokes *is* indefinite: it has lots of negative eigenvalues due to pressure being a Lagrange multiplier. The one-dimensional null space is not the problem. (We recommend setting it using MatSetNullSpace(), then just ensure that your right hand sides are consistent and everything should work fine.) The indefiniteness/saddle point is the problem. ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
