# [Maxima] more three problems...

Rainer Joswig joswig at lisp.de
Fri May 4 16:40:30 CDT 2007

```In article <463BA4D1.60902 at ericsson.com>,
Raymond Toy <raymond.toy at ericsson.com> wrote:

> Rainer Joswig wrote:
> > Maxima 5.12.0
> >
> > I got the Lisp part mostly running under LispWorks 5.
> >
> > Three remaining problems from the testsuite:
> >
> >
> > Running tests in rtest9:
> > ********************** Problem 18 ***************
> > Input:
> > errcatch(ev(%, x = 1.0E+20))
> >
> >
> > Result:
> > [7.000000000000015E+19]
> >
> > This differed from the expected result:
> > [7.0E+19]
>
> Can you evaluate (in Lisp)
>
> (+ (* 1d-20 (expt 1d20 2)) (* -5.5d0 1d20) 5.2d20)?
>
> Does this produce 7d19 or something else?

7.000000000000013E19

>
> >
> >
> >
> >
> >
> >
> > Running tests in rtest_trig:
> >
> > ********************** Problem 60 ***************
> > Input:
> > block([buggy : []], for f in alltrig do for p in pts do block([e,
> > fop : op(f)], e : buildq([p, fop], lambda([],
> > cabs(float(rectform(fop(p))) - fop(float(p))))),
> > if e() > 1.0E-13 then buggy : cons(e, buggy)), buggy)
> >
> >
> > Result:
> > The number 1.0*%i+2.0 isn't in the domain of acot
> >  -- an error.  To debug this try debugmode(true);
> > 0
>
> In maxima, try acot(2.0+%i*1.0);  If that produces an error, try
> atan(1/(2.0+%i*1.0)).  If that doesn't work, use Lisp and evaluate (atan
> (/ #c(2d0 1d0))).

(%i3) acot(2.0+%i*1.0);
The number 1.0*%i+2.0 isn't in the domain of acot
-- an error.  To debug this try debugmode(true);

(%i4) atan(1/(2.0+%i*1.0));
1
(%o4)                atan(------------)
1.0 %i + 2.0

>
> Ray

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```