[Octave-bug-tracker] [bug #49408] ode{23, 45} option "Refine" has no effect

[Carlo de Falco]

URL:
  <http://savannah.gnu.org/bugs/?49408>

                 Summary: ode{23,45} option "Refine" has no effect
                 Project: GNU Octave
            Submitted by: cdf
            Submitted on: Fri 21 Oct 2016 10:14:31 PM CEST
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.2.0-rc2
        Operating System: Any

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Details:

consider the following test in Matlab 2016a:


>> [t, y] = ode45 (myfun, [0 1], 1, odeset ('maxstep', 1, 'initialstep', .1,
'refine', 3)); t.'
ans =
         0    0.0333    0.0667    0.1000    0.2667    0.4333    0.6000   
0.7333    0.8667    1.0000
>> [t, y] = ode45 (myfun, [0 1], 1, odeset ('maxstep', 1, 'initialstep', .1,
'refine', 1)); t.'
ans =
         0    0.1000    0.6000    1.0000


the same code when run in Octave returns:


>> [t, y] = ode45 (myfun, [0 1], 1, odeset ('maxstep', 1, 'initialstep', .1,
'refine', 3)); t.'
ans =
   0.00000   0.10000   0.25000   0.47500   0.81250   1.00000
>> [t, y] = ode45 (myfun, [0 1], 1, odeset ('maxstep', 1, 'initialstep', .1,
'refine', 1)); t.'
ans =
   0.00000   0.10000   0.25000   0.47500   0.81250   1.00000


it seems that the intermediate steps are computed in integrate_adaptive 
but not added to the output.





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