#2264 radcan generates floats?

closed
nobody
5
2014-08-25
2011-08-25
No

See also bug report ID: 2990192

INPUT

build_info();
display2d : false;
radcan(sqrt(sqrt(2)+1/2));

INPUT AND OUTPUT

(%i1) build_info();
Maxima version: 5.25.0
Maxima build date: 12:0 8/2/2011
Host type: i686-pc-mingw32
Lisp implementation type: Clozure Common Lisp
Lisp implementation version: Version 1.7-r14925M (WindowsX8632)
(%o1)
(%i2) display2d : false;
(%o2) false
(%i3) radcan(sqrt(sqrt(2)+1/2));
rat: replaced 1.5 by 3/2 = 1.5
(%o3) sqrt(2^(3/2)+1)/sqrt(2)

Discussion

  • Raymond Toy

    Raymond Toy - 2011-08-26

    It seems to come from csign or sign. radcan calls simpexpt which calls csign which eventually calls numer. I don't know if csign should be trying to convert the expression to a numerical result. Could be a bug in numer too.

     
  • Dieter Kaiser

    Dieter Kaiser - 2011-10-26

    This bug is related to the bug 3185855 - radcan warns about float-convert. It is the same problem. A correction is to modify the function numer in the file compar.lisp. See bug 3185855.
    Dieter Kaiser

     
  • Dieter Kaiser

    Dieter Kaiser - 2011-10-27
    • status: open --> closed
     
  • Dieter Kaiser

    Dieter Kaiser - 2011-10-27

    Fixed in compar.lisp revision 27.10.2011
    Closing this bug report as fixed.
    Dieter Kaiser

     

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