#408 asin(x) and acos(x) plainly wrong

closed
nobody
None
5
2003-12-06
2003-10-01
No

The asin and acos functions are compete wrong. Using
Maxima 5.9.0 with GCL (Debian's package maxima 5.9.0-11):

(C1) asin(0.5);
(D1) 0.5
(C2) asin(0.9);
(D2) 0.9
(C3) asin(1);
%PI
(D3) ---
2

In fact, plot2d(asin(x), [x, -4, 4]) shows that asin
has nothing to do with the arcsine function (same
problem with acos).

Discussion

  • James Amundson

    James Amundson - 2003-10-01

    Logged In: YES
    user_id=28457

    Wow. That is very bad. The problem seems to be a bad interaction
    between (presumably) newer versions of GCL and Maxima. The
    GCL-Maxima 5.9.0 we distribute in RPM does not have the problem:

    ------------------------------------------------------------------
    (C1) build_info();

    Maxima version: 5.9.0
    Maxima build date: 22:24 2/9/2003
    host type: i386-redhat-linux-gnu
    lisp-implementation-type: Kyoto Common Lisp
    lisp-implementation-version: GCL-2-5.0

    (D1)
    (C2) asin(0.5);

    (D2) 0.5235987755983
    ------------------------------------------------------------------

    The GCL-Maxima I have in my development area (which I think is
    identical to the current cvs), when compiled with a recent cvs version
    of GCL, does have the problem:
    ------------------------------------------------------------------
    (C1) build_info();

    Maxima version: 5.9.0.1cvs
    Maxima build date: 7:43 9/25/2003
    host type: i686-pc-linux-gnu
    lisp-implementation-type: Kyoto Common Lisp
    lisp-implementation-version: GCL-2-6.0999999999999996

    (D1)
    (C2) asin(0.5);

    (D2) 0.5
    ------------------------------------------------------------------

    Please send the build_info() output for your Maxima.

     
  • Jaime E. Villate

    Logged In: YES
    user_id=28692

    Yeah, I also have the recent GCL version:

    (C1) build_info();
    Maxima version: 5.9.0
    Maxima build date: 19:17 9/9/2003
    host type: i686-pc-linux-gnu
    lisp-implementation-type: Kyoto Common Lisp
    lisp-implementation-version: GCL-2-6.0999999999999996

     
  • Raymond Toy

    Raymond Toy - 2003-12-06

    Logged In: YES
    user_id=28849

    Doesn't happen anymore.

     
  • Raymond Toy

    Raymond Toy - 2003-12-06
    • status: open --> closed
     

Log in to post a comment.

Get latest updates about Open Source Projects, Conferences and News.

Sign up for the SourceForge newsletter:





No, thanks