Singular
http://www.singular.uni-kl.de/forum/

solving systems of polynomials with parameters(symbols)
http://www.singular.uni-kl.de/forum/viewtopic.php?f=10&t=1500
Page 1 of 1

Author:  kamlesh [ Mon Jun 12, 2006 11:58 pm ]
Post subject:  solving systems of polynomials with parameters(symbols)

Hello ,
I have a system of polynomial equations in variables as well as in parameters . I want to solve it in variables ( in terms of a parameters and a chosen variable ) . Tried using the solve command after computing the grobner basis . It says the system has parameters and refused to solve it .
Whereas the same problem was solved using mathematica .

I need to do it using singular , can somebody tell me where am I wrong ?

// The actual problem
f1 = D + 2AC + A^2 + 2B - c = 0 ;
f2 = A^2 + 2BD + 2ABC + B^2 - d = 0 ;
f3 = B^2D - e =0 ;
f4 = AD-BC = 0;

with B,C,D,A as variables in lex ordr and c,d,e are parameters .

mathematica gives a 6th deg polynomial in B with coeffs ( coming from the parameters ) , and other var expressed in terms of B and parameters .

//

Can anybody suggest other useful topics to look into for dealing with similar problems ?

kamlesh

Author:  kamlesh [ Tue Jun 20, 2006 6:11 pm ]
Post subject: 

hmmm yeah was finally able to extract the required information .
The trick is to find the groebner basis with various ordering of the variables ( all in lp ) and then use the necessary polynomials and get the answer

kamlesh

Author:  momo [ Tue Dec 17, 2013 11:13 am ]
Post subject:  Re: write in code

kamlesh wrote:
hmmm yeah was finally able to extract the required information .
The trick is to find the groebner basis with various ordering of the variables ( all in lp ) and then use the necessary polynomials and get the answer

kamlesh



Yeah, I have the same problem.
I tried it, but not enough memory.

I define such thing:

ring r=(0,c,d,e),(A,B,C,D),lp;
ideal i=f1,f2,f3,f4;
groebner (i);

will it work like that?

momo

Page 1 of 1 All times are UTC + 1 hour [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/