Re: [Axiom-developer] choose the better expand

[Francois Maltey]

Dear Martin,

> You probably should provide the three syntaxs.

OK.

> Could you define (exactly!) what expand is supposed to do. 
> I guess that it's similar to ... maxima...

I don't forget mupad, results are (almost) the same.
I'm looking for a syntax which is easy for easy computation 
but which allows various interessing abilities.

But might you help me for extracting real part and imag part for 
Expression ... Complex ... ? in manip.spad.
Perhaps do you want I send you my working manip.spad.

I'm going to test an expand which 
     1/ separates real part and imag part, if it's a Complex domain
then 2/ always applies sum formula,
 and 3/ applies Integer * formula_without_denominator
for sin, cos, tan, cot, sinh, cosh, tanh, coth, exp...

A list of String describes the parameters and precises the expand use : 

noComplex bypass the first step, noSum the second, noTimes the third.
allDenom  expands also sin (2*x/3) in 2 sin (x/3) cos (x/3)
evenConst expands sin (sqrt 2 + sqrt 3) in sin... cos... + cos... sin...
recursif  does the silly expand (sin (sin (a+b)))
?????     expands sin (x/3+y/2) * cos (x/2-y/7) in sin... cos... x/6 and y/14 !
          (but I'm not sure I can do it !)

Good night !

Francois