[Fwd: some Maxima questions -- 2nd attempt]

I am forwarding this message on behalf of Tony Brocci, who is unable to
send directly to the maxima list.
-- 
James Amundson <amundson@fnal.gov>

Date: Tue, 11 Feb 2003 12:59:23 -0500 (EST)
From: R A Brocci <brocci at kaplmail>
Subject: some Maxima questions -- 2nd attempt

Jim Amundson:

First of all, I need to state that:

   o  Only a person with "root" privileges can install software
      at our site.

      I mention this simply because I don't know what else might
      have been done after Maxima's "self install" completed.

   o  Maxima was installed under the XP OS, since it's the OS of
      our (near) future, and I was unable to convince the system
      types that I needed to have it installed under the NT OS,
      as stated on your website.

   o  If you think, or if you prefer to handle, Maxima questions
      via the phone, please let me know your number and a window
      of time where dealing with questions would be convenient
      for you, and I'll do just that.

   o  For what it's worth, all references to any Macsyma results
      refer to (the former Macsyma, Inc's)

         Unix Version 422

      running on an SGI machine.

 1. Your website indicated that I'd downloaded Version 5.6, but
    the Maxima invocation says it's Version 5.5.

    So, did I issue some erroneous click(s) on the download?  (It
    was done early this year.)

    Should I download another version?  In particular, is there
    an XP version I should download?

 2. I have been unable to capture a Maxima session via the

       writefile( "some_name.extension" ) ;

    command, in that the file is present but has zero size.

    In addition, the use of the

       closefile( "..." ) ;

    command does not change this result.

    Note: The same thing happens with the

       stringout( "...", ... ) ;

    command, which in turn means we haven't really been able to
    exercise the

       fortran( ... ) ;

    command to the extent we'd like.

    Note: This result seems strange, since the

       batch( "..." ) ;

    command works just fine.

    Note: The writefile observation was confirmed by a colleague
    who has Maxima installed under OS 2000 at home.  (He says it
    is also Version 5.5; i.e., the same version as here.)

    Note: The

       describe(writefile) ;

    command responds with the

       dsk, directory

    arguments, but our attempts to interpret them with viable

       writefile( "...", "..." ) ;

    argument strings have been futile.

    Note: According the mail archives, Tim Auton asked the same
    question re the writefile command on 23 Apr 2001.  With a hint
    from Jim Amundson, I searched the archives for the writefile
    string, and don't believe I missed the answer.  (But perhaps I
    did.)

 3. Do you think this version of Maxima is capable of inverting an
    N x N matrix, where N is > 10?  I'm sure your answer is yes,
    but:

    For N = 24, a colleague let Maxima run over night, and the next
    morning, it appeared from a screen back-scroll that Maxima had
    "lost its way."

    Note: I believe that N = 24 is a rather typical application for
    this colleague.

    This individual then used the

       batch( "..." ) ;

    command to import the Unix Macsyma version of the inverse of the
    24 x 24 matrix, along with the terms of a 24 x 1 vector.  With
    these entries, he then issued the

       B . V

    command, where B is the inverse matrix and V is the vector.  He
    obtained the 24 x 1 null vector, which he knows to be wrong, and
    which I could clearly see is wrong for just the

       1st row of B . V

    term.  Any thoughts as to what might be happening here?

    Note: For this colleague, it is typical for him to form a N x N
    matrix (say A), invert it, and use the

       stringout( "...", ... ) ;

    command on the inverse in his "1st" session, and then import the
    inverse and various vectors in subsequent sessions via the

       batch( "..." ) ;

    command.

    In general, if you have any N versus inversion times on various
    platforms, I'd appreciate seeing them.  More precisely, I would
    welcome any info on Maxima's matrix capability that you feel is
    pertinent to the situation I've described above.

 4. When I double click on your illustrative

       describe(log) ; all

    command, everything is fine.  However, if I enter the

       describe(log) ;

    command, look at my options and then enter my answer, Maxima
    does not respond unless I type

       answer ;

    which in turn leads to a diagnostic message associated with
    the trailing semicolon before the next

       (C...)

    prompt appears.

    Note: The "solution" to this situation is to enter

       answer;

    which doesn't seem to be in-sync with Maxima's philosophy of
    not really caring where the terminating semicolon appears.

 5. The word Macsyma appears in many places other than statements
    regarding Maxima's origin; e.g., in some of the

       describe(X) ;

    commands I've issued.

    I would think Maxima's origin is the only appropriate place
    for Macsyma to appear.  That is, whether one has never used
    Macsyma, or is a long-time user like myself, Maxima's capa-
    bility should stand by itself, in my opinion at least.

    Or, are you attempting to distinguish between what came with
    the Macsyma Prof. Schelter started with, and what your group
    has done to enhance this version?

 6. The

       quit() ;  or  ctrl_C ctrl_G (without the ; character)

    command does not shutdown the Maxima session; i.e., the window
    doesn't disappear, and the "blinking cursor" appears after the
    enter key is hit.

    Is this result to be expected?  If so, is it possible to bind
    a site-specific version of

       quit() ;  or  ctrl_C ctrl_G

    to xmaxima?  That is, and for example, a quit() function where
    the Maxima screen does disappear?

    Note: I mention this simply because we'd like to keep track of
    who's using Maxima, and how often they're doing so.  (I have
    found that such info is absolutely invaluable when you have to
    deal with the system types who seem to be always asking why we
    need to retain package X.)

    Note: I can handle the who's using issue via a (perl) script,
    but I can't handle the frequency issue without having the

       quit() ;  or  ctrl_C ctrl_G

    command mean the same as your current

       File->Exit

    button.

Many thanks for your help!

Tony Brocci
KAPL, Inc
Mail Stop 123
PO Box 1072
Schenectady, NY  12301

518-395-6682  (voice)  and -4422 (fax)

brocci@kapl.gov