[Octave-bug-tracker] [bug #46189] ode45: number of function evaluations overestimated in stats

[Carlo de Falco]

URL:
  <http://savannah.gnu.org/bugs/?46189>

                 Summary: ode45: number of function evaluations overestimated
in stats 
                 Project: GNU Octave
            Submitted by: cdf
            Submitted on: Mon 12 Oct 2015 10:40:18 PM CEST
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: In Progress
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: dev
        Operating System: Any

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Details:


I use the attached script (extracted from odepkg) to evaluate the 
performance of ode45 while I am working on its improvement.

This is its output running on my system under the profiler


Testsuite HIRES, testing solver   ode45 with relative tolerance 1e-07
-----------------------------------------------------------------------------------------
 Solver  RelTol  AbsTol   Init   Mescd    Scd  Steps  Accept  FEval  JEval 
LUdec    Time
-----------------------------------------------------------------------------------------
  ode45   1e-07   1e-07   1e-09   7.58   5.17  12334   20860  86331           
    32.140
-----------------------------------------------------------------------------------------
-verbatim

notice that it reports 86331 "FEvals", while via profexplorer one can
see the following:


Top
  performance: 1 calls, 30.842 total, 0.037 self
    odepkg_testsuite_hires: 1 calls, 30.804 total, 0.001 self
      feval: 1 calls, 30.778 total, 0.000 self
        ode45: 1 calls, 30.778 total, 0.002 self
          integrate_adaptive: 1 calls, 30.768 total, 4.676 self
            runge_kutta_45_dorpri: 12333 calls, 23.810 total, 5.381 self
              feval: 73999 calls, 18.096 total, 1.828 self
                1) odepkg_testsuite_hiresfun: 73999 calls, 16.267 total,
15.414 self



so the function evaluator "odepkg_testsuite_hiresfun" has been actually
invoked only
73999 times and the stats returned by ode45 appear to overestimate this
number.





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File Attachments:


-------------------------------------------------------
Date: Mon 12 Oct 2015 10:40:18 PM CEST  Name: performance.m  Size: 5kB   By:
cdf

<http://savannah.gnu.org/bugs/download.php?file_id=35171>

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