ASKSAGE: Sage Q&A Forum - Latest question feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Fri, 20 Sep 2013 01:06:43 -0500semialgebraic systems in Sagehttps://ask.sagemath.org/question/10552/semialgebraic-systems-in-sage/I would like to solve systems such as
solve([x^3-y^2 == 0, x<0, x^2+y^2<1], x, y)
I get
[[x < 0, -x^2 - y^2 + 1 > 0, -x^3 + y^2 == 0]]
i.e., the same thing.
W|A, for instance, says that "no solutions exist". Also Maple can easily deal with the system. Is there any package I'm missing? Are these systems manageable with Sage (or an embedded software)?
Thank you.
fbtnFri, 20 Sep 2013 01:06:43 -0500https://ask.sagemath.org/question/10552/How do I find a solution of a set of inequalities?https://ask.sagemath.org/question/9744/how-do-i-find-a-solution-of-a-set-of-inequalities/Help with coding please. I'm completely new to Sage.
I have a model system written in Python and I need to do recursively call a subroutine to determine the existence of a solution of a set of inequalities. We have a primitive subroutine written, but I'd rather not reinvent the wheel.
Mathematica can do it easily It takes two calls "Resolve[Exists[ {set of variables}, {set of inequalities}. The output is either True or False.
I tried to research calling Mathematica from my python code, but it seems like a big detour technical from my actual research. The same for Matlab. I need to call on an external symbolic calculus program, have the answer returned to python and continue computing. Sage seems perfect for this. The introduction video says that anything Mathematica can do, sage should be able to do it too. Here's my question: HOW?
I know you can import sage from any python script, but what packages do I import? What commands do I use?
For example, if the following set is my symbols: {g1 g2 g3 t11 t12 t21 t32 k11 k21 k22 k31} for this set of inequalities { k11 > g1*t11 && k11 < g1*t12 && 0 < g1*t11 && k11 > 0 && k21 > g2*t21 && (k21 + k22) < g2*t21 && 0 < g2*t21 && k22 < 0 && k31 > g3*t32 && k31 > g3*t32 && 0 < g1*t11 && k11 > g1*t11 && (k11*k11) < (k11 + k11)*g1*t11}.
diana_doing_math_in_italyTue, 05 Feb 2013 01:36:44 -0600https://ask.sagemath.org/question/9744/