ASKSAGE: Sage Q&A Forum - Individual question feedhttp://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Mon, 06 Jun 2011 15:57:25 -0500Groebner basis for rational functions with real coefficientshttp://ask.sagemath.org/question/8151/groebner-basis-for-rational-functions-with-real-coefficients/Does anybody know if sage supports computing groebner basis for an ideal of rational functions with real coefficients? I can do this in mathematica, but when using sage I get the error:
verbose 0 (2416: multi_polynomial_ideal.py, groebner_basis) Warning:
falling back to very slow toy implementation.Mon, 06 Jun 2011 07:36:40 -0500http://ask.sagemath.org/question/8151/groebner-basis-for-rational-functions-with-real-coefficients/Answer by Volker Braun for <p>Does anybody know if sage supports computing groebner basis for an ideal of rational functions with real coefficients? I can do this in mathematica, but when using sage I get the error: </p>
<p>verbose 0 (2416: multi_polynomial_ideal.py, groebner_basis) Warning:
falling back to very slow toy implementation.</p>
http://ask.sagemath.org/question/8151/groebner-basis-for-rational-functions-with-real-coefficients/?answer=12422#post-id-12422Just to phrase your question correctly, you want to work with a polynomial ring whose coefficient ring is rational functions with real coefficients.
You don't get an error, just a warning that there is no particularly fast implementation available. Singular just doesn't support it, so Sage falls back to its default implementation. Groebner basis computations over non-exact fields are generally iffy, so you should first think about whether you can rephrase your problem in an exact coefficient ring. Mon, 06 Jun 2011 15:57:25 -0500http://ask.sagemath.org/question/8151/groebner-basis-for-rational-functions-with-real-coefficients/?answer=12422#post-id-12422