> From: Raymond Toy
>
> >>>>> "Barton" == Barton Willis writes:
>
> Barton> -----Raymond Toy wrote: -----
>
> >> I've done some of this for the elliptic
> >> functions. One question: What should maxima
> >> do with sin(1 + 5.0*%i)? Leave it? Apply "numeric
> >> contagion" and pretend it was sin(1.0+5.0*%i) and
> >> evaluate numerically, even without the numer or float
> >> flags?
>
> Barton> I suggest we adopt "numeric contagion." One argument
>
> Yes, it's a simple rule that everyone is familiar with---everything is
> converted to the largest float type.
>
> Barton> Since 1.0 * %i --> %i, numeric contagion has a problem:
> Barton> cos(1 + 1.0 * %i) --> cos(1 + %i), yet cos(1 +
> 1.0001 * %i) -->
> Barton> complex double float. Sigh.
>
> Hmm. That is a problem. I suppose we could turn off the conversion
> of 1.0*%i to %i.
>
I struck this when I was implementing Airy functions. The conversion
of 1.0*%i to %i interferes with the numerical evaluation of airy(%i).
(%i2) airy(1.0);
(%o2) 0.13529241631288
(%i3) airy(1.0*%i);
(%o3) airy(%i)
It would be useful to document and test the desired behaviour. What do we
expect from airy(1). I see now that this returns a numerical result.
I think I made a mistake in doing that.
D
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