[Scipy-tickets] [SciPy] #360: Callback function is broken in linalg.gmres

SciPy scipy-tickets@scipy....
Sat Nov 29 20:10:27 CST 2008


#360: Callback function is broken in linalg.gmres
--------------------------+-------------------------------------------------
 Reporter:  nils          |        Owner:  somebody
     Type:  defect        |       Status:  new     
 Priority:  normal        |    Milestone:  0.7.0   
Component:  scipy.linalg  |      Version:  devel   
 Severity:  normal        |   Resolution:          
 Keywords:                |  
--------------------------+-------------------------------------------------
Comment (by pv):

 Seems to work (nearly) as expected in Scipy 0.7.0.dev5207:
 {{{
 270
 1.26310356863e-10
 ||A.x - b|| = 0.753828964374
 ||A.x - b|| = 0.580550336493
 ...
 ||A.x - b|| = 7.25792987592e-10
 ||A.x - b|| = 7.22835341023e-10
 270
 The residual by callback is 7.22835341023e-10 but should be
 9.68244137814e-11
 }}}
 The last residual is not passed to the callback, however, but IMHO this is
 not really promised in the docstring.

 NB: The argument to the callback is the residual itself
 {{{
 def callback(res):
     print "||A.x - b|| = " + str(linalg.norm(res))
     data.append(linalg.norm(res))
 }}}

-- 
Ticket URL: <http://scipy.org/scipy/scipy/ticket/360#comment:2>
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