[Maxima] Simplification question

Stavros Macrakis macrakis at alum.mit.edu
Wed May 28 10:47:46 CDT 2008

```Please try again using lowercase input -- which gives the correct
answer in 5.14.  Current Maxima (unlike older versions) is
case-sensitive, so 'SIN' is treated as an undefined function, not as
the trigonometric function sine, which is written 'sin'.

-s

On Wed, May 28, 2008 at 11:19 AM, David Ronis
<ronis at ronispc.chem.mcgill.ca> wrote:
> I just tried the examples listed in the documention you've listed, and
> may have found a bug in 5.15.0cvs.  The last example given in the
> tutorial is:
>
>
> (c3) foo:X^2*SIN(Y)^4-2*X^2*SIN(Y)^2+X^4*COS(Y)^4-2*X^4*COS(Y)^2+X^4+X^2
> +1\$
>
> (c4) trigsimp(foo);
>        4    2     4         4    2       4
> (d4) (x  + x ) cos (y) - 2 x  cos (y) + x  + 1
>
> /* That helps, but this is better: */
> (c5) format(foo,%poly(x),trigsimp);
>       4    4       2    4
> (d5) x  sin (y) + x  cos (y) + 1
>
> However when I run it I get:
>
> (%i1) foo:X^2*SIN(Y)^4-2*X^2*SIN(Y)^2+X^4*COS(Y)^4-2*X^4*COS(Y)^2+X^4+X^2+1\$
> (%i2) trigsimp(foo);
>       2    4         2    2       4    4         4    2       4    2
> (%o2) X  SIN (Y) - 2 X  SIN (Y) + X  COS (Y) - 2 X  COS (Y) + X  + X  + 1
>
> (%i5) format(foo,%poly(x),trigsimp);
>       2    4         2    2       4    4         4    2       4    2
> (%o5) X  SIN (Y) - 2 X  SIN (Y) + X  COS (Y) - 2 X  COS (Y) + X  + X  + 1
>
> Which isn't what the tutorial returns.
>
> David
>
> On Tue, 2008-05-27 at 19:52 -0700, Richard Fateman wrote:
>> there is actually no reason to expect Maxima to "simplify" an expression to
>> some arbitrary form that you happen to like;
>> Maxima has its own particular repertoire of "kinds of simplifications"  and
>> getting exactly the ordering you want may be contrary to its rules.  On the
>> other hand, there is a package that tries to come up with a formatting
>> arrangement that might allow for something like this form. Bruce Miller
>> wrote it, and it is called format.  e.g. load(format) does it.
>> documentation?? see http://math.nist.gov/~BMiller/computer-algebra/
>>
>>
>> > -----Original Message-----
>> > From: maxima-bounces at math.utexas.edu
>> > [mailto:maxima-bounces at math.utexas.edu] On Behalf Of Andreas Kranz
>> > Sent: Tuesday, May 27, 2008 1:08 PM
>> > To: maxima at math.utexas.edu
>> > Subject: [Maxima] Simplification question
>> >
>> > Hello,
>> >
>> > as a maxima newbie I've trouble understanding how to achieve
>> > a certain
>> > transformation.
>> >
>> > Especially I would like the following term:
>> >
>> >   2 vx z - r z - l z - 2 n (x - vx) - 2 vz x + r vz + l vz
>> > - --------------------------------------------------------
>> >                            r - l
>> >
>> > to be written as:
>> >
>> >
>> > 2(n + vz)      -2 vx    r + l       2 n vx + r vz + l vz
>> > --------- x + (----- +  -----) z +  --------------------
>> >   r - l        r - l    r - l              r - l
>> >
>> >
>> > probably an easy task for maxima but maybe I'm just to blind
>> > to see how
>> > to do this.
>> > I've already experimented with combinations of factorsum,
>> > factorout and
>> > friends but
>> > could not work that out.
>> >
>> > Any suggestions?
>> >
>> > Bye,
>> >
>> > Andreas
>> > _______________________________________________
>> > Maxima mailing list
>> > Maxima at math.utexas.edu
>> > http://www.math.utexas.edu/mailman/listinfo/maxima
>> >
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```