question about symbolic/numerical mixing



Stavros Macrakis schrieb:

> 
> (%i9) float:true$
> (%i10) resimplify(exprlist);
> (%o10) [-x,0.13616664909625,a*x]
>       /* float flag controls %pi -> float */

Interestingly, I was not able to reproduce this output, with float:true, 
still %pi remains the symbolic constant.

wxMaxima 0.8.1 http://wxmaxima.sourceforge.net
Maxima 5.17.1 http://maxima.sourceforge.net
Using Lisp GNU Common Lisp (GCL) GCL 2.6.8 (aka GCL)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i24) kill(all);numer:false;float:false;
(%o0) done
(%o1) false
(%o2) false
(%i3) exprlist: [ abs(x), sin(%pi/23), x*a ]$
(%i4) resimplify(expr):= expand(expr,1,1);
(%o4) resimplify(expr):=expand(expr,1,1)
(%i5) resimplify(exprlist);
(%o5) [abs(x),sin(%pi/23),a*x]
(%i6) assume(x<0)$
(%i7) resimplify(exprlist);
(%o7) [-x,sin(%pi/23),a*x]
(%i8) numer:true$
(%i9) resimplify(exprlist);
(%o9) [-x,sin(0.043478260869565*%pi),a*x]
(%i10) float:true$ /* <<<<<<<<<<<<<<<<<<<<<<<<<<< */
(%i11) resimplify(exprlist);
(%o11) [-x,sin(0.043478260869565*%pi),a*x]
(%i12) assume(equal(a,0))$
(%i13) resimplify(exprlist);
(%o13) [-x,sin(0.043478260869565*%pi),a*x]
(%i14) a: 23$
(%i15) resimplify(exprlist);
(%o15) [-x,sin(0.043478260869565*%pi),a*x]
(%i16) ev(exprlist);
(%o16) [-x,0.13616664909625,23*x]