[Octave-bug-tracker] [bug #59416] ode15s produce results with inconsestance size when compared to other ode solver or matlab.

[Hg200]

Follow-up Comment #7, bug #59416 (project octave):

Rik is correct (comment #4) and also Markus is correct (comment #6)

When executed under Matlab R2018b one of the Octave ode15s BISTs returns 

++
ref = [-1.205364552835178, 0.951542399860817];
sol = ode15s (@fpol, [0 -2], [2, 0]);
assert ([sol.x(end), sol.y(end,:)], [-2, ref], 5e-3);
size([sol.x(end), sol.y(end,:)])
ans =
     1    37
--

So we have to adopt the assert line :

++
assert ([sol.x(end), sol.y(end,:)], [-2, ref], 5e-3);

must be

assert ([sol.x(end), sol.y(:,end).'], [-2, ref], 5e-3);
--

And the output of the functions ode15i and ode15s is weird:

++
[t, x] = ode15i (@f, tspan, x0, x0dot, options);
size(t)
ans =
   557     1
size(x)
ans =
   557     2
--
But
++
z = ode15i (@f, tspan, x0, x0dot, options);
  struct with fields:

     solver: 'ode15i'
    extdata: [1x1 struct]
          x: [1x557 double]
          y: [2x557 double]
      stats: [1x1 struct]
      idata: [1x1 struct]
--

I also see some other issues in the BISTs. References for functions are
sometimes "strings" and sometimes "@" (mixed). That should be corrected too. I
am going through the BISTs and check for errors.

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