Re: Teaching maxima a new identity

Macrakis wrote:

>
>  I don't have time to look at the details, but did you try 
> ratsimp(expr),algebraic:true (with the tellrat in force) on the result?

I have been trying to learn Maxima for some time now and I have a few 
observations I would like to pass on.
1) The learning curve for simplification is way too steep.
    Maxima must be improved in this area. Here is an example:
While trying to write a batch file to explicitly factor a 3rd order 
polynomial into its 1st and 2nd order parts, I gave the program a known 
set of numerical values just to see if I had made any typos yet. The 
answer was not what I was expecting so I went through the code but could 
find no fault there. So to make a long story short, after much time I 
found  that the answer  was just a long way of saying 0.
Here it is:

(%i28) EV(a9,NUMER)
(%o28) 
0.03703703703704*(0.57735026918963*(-1)^0.16666666666667*(27.0*(-%I)^0.66666666666667-27)
            -31.1769145362398*(-%I)^0.33333333333333)
(%i29) EV(a9,RATSIMP)
(%o29) 0
(%i30) EV(REALPART(a9),NUMER)
(%o30) -1.0
(%i31) EV(IMAGPART(a9),NUMER)
(%o31) -1.732050807568877

Now I don't know what to believe!!!!!

Re: Teaching maxima a new identity

Doug,

Agreed entirely that it's way too hard to get a handle on the
bazillions of permutations of Maxima functions. Sorry about that.

> (%i28) EV(a9,NUMER)
> (%o28)
> 0.03703703703704*(0.57735026918963*(-1)^0.16666666666667*(27.0*(-%I)^0.66666666666667-27)
>             -31.1769145362398*(-%I)^0.33333333333333)

What is a9 here?

I don't have any answers for you, but knowning a9 would help us
track down the imagpart/realpart strangeness.

Sorry I can't be more helpful,
Robert Dodier

Re: Teaching maxima a new identity

Doug Stewart wrote:
<emotions are skipped>
> etc, but not in Maxima.
> When you get it working I will try it again.
It is not possible to advance with such an angry mood ...
Here, we are working together on the common project, even if
every participant could have a particular interest.

rgds,
Valery

Re: triangularize behaving unexpectedly

> This issue was discussed at length in bug 1064238 "triangularize gives
> wrong results."
> (http://sourceforge.net/tracker/?group_id=4933&atid=104933&func=detail&aid=1064238)

I've closed that bug report. Here are my comments on it.

"triangularize appears to carry out Gaussian elimination, and
is observed to yield the same thing as echelon except that
the leading coefficient isn't necessarily 1. I've updated
Matices.texi to say that. Also the description of
triangularize now mentions LU and Cholesky as other things.
Closing this report as fixed."

Robert Dodier

install on mac os x tiger

Re: install on mac os x tiger

>>>>> "Richard" == fell  <Fell> writes:

    Richard> I suspect that I should install some lisp first and then
    Richard> the maxima source code and follow the instructions. But,
    Richard> what lisp. And a

I believe clisp, cmucl, gcl, openmcl, and sbcl should all work on Mac
OS X Tiger.  I have personally built maxima with cmucl and clisp
(older version, though) on Tiger and it works just fine.  I think
plotting works too, if you get gnuplot.  (Might have to use the X
version; I don't remember.)  But I don't actually use maxima all that
much.

    Richard> question out of curiosity. Once a lisp is installed, how
    Richard> does maxima know where to look for it in my directory
    Richard> tree?

When you build maxima, you can tell configure where your lisp is.  Or
just adjust PATH to include your lisp.  After that, maxima will know
where your lisp binary is when you install it.  I think.

Ray

Re: install on mac os x tiger

>>>>> Fell <fell <at> brandeis.edu> (F) wrote:

>F> Kindly people -
>F> After successfully installing the latest macsyma on redhat 9.2, due
>F> entirely to the excellent  instructions sent to me by Robert Dodier  (many
>F> thanks again), I am ready to install on my mac here at school  on which I
>F> have the latest os x, tiger.

>F> I suspect that I should install some lisp first and then the maxima  source
>F> code and follow the instructions. But, what lisp. And a  question out of
>F> curiosity. Once a lisp is installed, how does maxima  know where to look
>F> for it in my directory tree?

Clisp would be the best IMHO. I installed clisp with darwinports, but I
gues you can as well use fink, or compile yourself from source.

GCL is much faster but it fails on test14, basically because it crashes
with some of the numerical calculations.

I have also tried OpenMCL but it did not work. SBCL seems to work too.
You can have maxima with different lisps installed at the same time, and
run e.g. maxima --lisp=sbcl.

If your lisp is in a directory that is in your PATH then it will be found
automatically. Otherwise for installation use
./configure --with-clisp=/dir/to/clisp or similar.
--

-- 
Piet van Oostrum <piet <at> cs.uu.nl>
URL: http://www.cs.uu.nl/~piet [PGP 8DAE142BE17999C4]
Private email: piet <at> vanoostrum.org

Re: plotting functions e^x and log(x)

>>>>> "Robert" == Robert Jerrard <rjerrard <at> math.concordia.ab.ca> writes:

    Robert> Yes, that is unfortunate, adaptive sample for parametric plots would be
    Robert> nice.
    >> 
    >> Laziness on my part.  Probably wouldn't be too hard, without having
    >> looked at it at all. 

    Robert> That would be excellent also. Thanks, Ray

I took a look, and, in fact, it's different enough that it means it
has to be new code, I think.  The previous adaptive plot just checked
to see if the y values were close enough.  Now you have to check both
the x and y values are close enough, so this is different.  Might be
able to use the same criteria as the adaptive plot to make this
happen, but I'm not sure.

In either case, it seems like new code is required.  So real
development needs to be done. 

Ray

Re: install on mac os x tiger

>>>>> Raymond Toy <raymond.toy <at> ericsson.com> (RT) wrote:

>RT> I think plotting works too, if you get gnuplot. (Might have to use the
>RT> X version; I don't remember.) 

There is a version of gnuplot with Aquaterm. This works without X11, also
from maxima.
--

-- 
Piet van Oostrum <piet <at> cs.uu.nl>
URL: http://www.cs.uu.nl/~piet [PGP 8DAE142BE17999C4]
Private email: piet <at> vanoostrum.org

Small bug - load(file.mc) fails if there is no empty lines at the end of the file - also reported at Sourceforge #1345803.

Dear Maxima people, 

Load, batch, and batchload stopped working for a number of files when I
upgraded from 5.9.1 to 5.9.2, and this is at least a workaround that
works for me. 
(Add a newline at the end of the files.)

Below I will illustrate the contents of two files, delimited by ----,
then the commands that provoke the bug.

Maxima is great. Thanks for the good work!

Best regards,
                      Goran Christiansson
                     g.a.v.christiansson <at> wbmt.tudelft.nl

-------------- show_bug.mc:
/* Small program to illustrate a small bug in Maxima 5.9.2, on Windows
XP */
a:34;
------------ no_bug.mc
/* Small program to illustrate a small bug in Maxima 5.9.2, on Windows
XP */
a:34;

----------- (note the empty line at the end of the file)

A session:
========================================================================
=
Using Lisp GNU Common Lisp (GCL) GCL 2.6.7 (aka GCL)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
This is a development version of Maxima. The function bug_report()
provides bug reporting information.
(%i1) load(show_bug);
Maxima encountered a Lisp error:

 Error in MACSYMA-TOP-LEVEL [or a callee]: Unexpected end of #<input
stream "D:/docs/hapticAnalysisPackage/examples/show_bug.mc">.

Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.
(%i2) load(no_bug);
(%o2) 	       D:/docs/hapticAnalysisPackage/examples/no_bug.mc
(%i3) bug_report();
The Maxima bug database is available at

http://sourceforge.net/tracker/?atid=104933&group_id=4933&func=browse
Submit bug reports by following the 'Submit New' link on that page.
Please include the following build information with your bug report:
-------------------------------------------------------------

Maxima version: 5.9.2
Maxima build date: 9:5 10/12/2005
host type: i686-pc-mingw32
lisp-implementation-type: GNU Common Lisp (GCL)
lisp-implementation-version: GCL 2.6.7

-------------------------------------------------------------
The above information is also available from the Maxima function
build_info().

---------------------------------------------
###########################################

This message has been scanned by F-Secure Anti-Virus for Microsoft Exchange.
For more information, connect to http://www.f-secure.com/