[Scipy-tickets] [SciPy] #1297: scipy.sparse.linalg.cg: more callback arguments (residual)

SciPy Trac scipy-tickets@scipy....
Fri Oct 8 14:14:04 CDT 2010


#1297: scipy.sparse.linalg.cg: more callback arguments (residual)
--------------------------+-------------------------------------------------
 Reporter:  nicki         |       Owner:  somebody
     Type:  defect        |      Status:  new     
 Priority:  normal        |   Milestone:  0.9.0   
Component:  scipy.linalg  |     Version:  0.8.0   
 Keywords:                |  
--------------------------+-------------------------------------------------
 Hi all,

 as discussed on http://mail.scipy.org/pipermail/scipy-
 user/2010-October/026891.html:

 The CG callback is commonly used to store the residual vector / norm to
 observe CG convergence history. Currently, the only argument to callback
 is the current approximation x_k out of which the residual r_k can be
 computed of course -- but only at the cost of an extra (expensive) matrix
 --vector multiplication.
 This is redundant as the residual is explicitly computed in the CG
 algorithm anyway.

 Cheers,
 Nico

-- 
Ticket URL: <http://projects.scipy.org/scipy/ticket/1297>
SciPy <http://www.scipy.org>
SciPy is open-source software for mathematics, science, and engineering.


More information about the Scipy-tickets mailing list