[Scipy-tickets] [SciPy] #1762: fmin_l_bfgs_b locks up

SciPy Trac scipy-tickets@scipy....
Fri Nov 2 18:55:04 CDT 2012

#1762: fmin_l_bfgs_b locks up
 Reporter:  jickerson       |       Owner:  somebody   
     Type:  defect          |      Status:  new        
 Priority:  normal          |   Milestone:  Unscheduled
Component:  scipy.optimize  |     Version:  0.10.1     
 Keywords:  l_bfgs_b        |  
 When trying even simple examples (with or with constraints), fmin_l_bfgs_b
 locks up completely. I put a print statement inside my called function,
 and find that it never gets called. I can't break out of the script with a
 keyboard interrupt, and once I restart the IDLE shell, I can see the
 process still running in the task manager and using the full CPU power.
 Here is output from a simple example (note: I removed the lines printed
 when fmin_bfgs called the function):

 from numpy import *
 from scipy.optimize import *
 x0 = array([4.5, 6.6])
 def a(x):
         print x
         return (x[0]-3.2 )**2+ (x[1]-4.4)**2

 bn = [(1.1, 7.7), (4.7, 8.5)]
 fmin_bfgs(a, x0)

 Optimization terminated successfully.
          Current function value: 0.000000
          Iterations: 2
          Function evaluations: 16
          Gradient evaluations: 4
 array([ 3.2       ,  4.39999999])

 fmin_l_bfgs_b(a, x0, approx_grad=True)


Ticket URL: <http://projects.scipy.org/scipy/ticket/1762>
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