On Wednesday, March 25, 2015 at 1:54:24 AM UTC+2, Luv Agarwal wrote:
>
>
> Is primitive_element doing something similar to simple 
> <https://github.com/sympy/sympy/wiki/GSoC-2015-Application-Luv-Agarwal:-Cylindrical-Algebraic-Decomposition#2-simple>?.
>  
> If yes, will there be difference in efficiency of both of these as they 
> take input in different form?.
>

primitive_element and simple do more or less the same thing. Both construct 
an extension containing given
algebraic elements. Their differences are

    1.  primitive_element takes any number of elements, simple only two.

    2.  simple computes isolating intervals, primitive_element does not 
care.

In more detail, primitive_element  uses  sqf_norm  which is just steps 1 
and 2 of simple combined.
(1. norm is computed as a resultant, 2. t  is chosen to make norm square 
free.)

As to efficiency, I don't think there would be essential difference, since 
the algorithms are basically
the same. Setting  ex=True (experimental?)  in primitive_element leads to a 
parallel variant using
Groebner bases. It might be more efficient for a large number of elements.

Kalevi

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