On Feb 21, 9:44 pm, "D. S. McNeil" <dsm...@gmail.com> wrote:
> > I think it's very appropriate to open a ticket for this. It would be
> > even more appropriate to try to construct a more minimal
> > counterexample :) but at least then we have it on the record.
>
> So far the best I can do is
>
> f(t) = e^(-(4.007 - 3*I)*t)
> integral(f, (t, 0, infinity))
>
> *boom*
>
> and note that 4007/1000 doesn't crash.
>
> Primality of the numbers seems to correlate with crashing (possibly
> due to how Maxima handles floats?), and the ones that don't blow the
Yes, that whole "replacing by a rational" thing...
sage: maxima_calculus(" integrate(%e^(-(4.007-3*%i)*t),t,0,inf)")
.11973156661690758*%i+.15992146247798286
So somehow part of it must be the exact thing we are sending to ECL.
More details.
In Maxima 5.26.0:
(%i3) display2d:false;
(%o3) false
(%i4) integrate(%e^(-(4.007-3*%i)*t),t,0,inf);
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
(%o4) (3000000*%i+4007000)/25056049
In our (older) one:
(%i1) display2d:false;
(%o1) false
(%i2) integrate(%e^(-(4.007-3*%i)*t),t,0,inf);
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -.1197315666169076 by -1463/12219 = -.1197315655945658
rat: replaced -.1599214624779829 by -2525/15789 = -.159921464310596
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -.1599214624779829 by -2525/15789 = -.159921464310596
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced .11973156661690758 by 1463/12219 = .11973156559456584
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -.1197315666169076 by -1463/12219 = -.1197315655945658
rat: replaced 3.0 by 3/1 = 3.0
rat: replaced -4.007 by -4007/1000 = -4.007
rat: replaced -.1599214624779829 by -2525/15789 = -.159921464310596
(%o2) .11973156661690758*%i+.15992146247798286
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