ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Tue, 05 Nov 2019 22:28:50 +0100maximizing sum over feasible set of vectorshttps://ask.sagemath.org/question/48630/maximizing-sum-over-feasible-set-of-vectors/Let $[5]$ be the set of the first 5 positive integers. We let $\underline{\alpha} =(\alpha_A)_{A\neq \emptyset, A\subseteq [5]}$ consist of a vector with $31$ real entries, where each $\alpha_A$ is associated with a subset $A \subseteq [5]$.
Define $\displaystyle OBJ(\underline{\alpha})=\sum_{A\subseteq [5], A\neq \emptyset} \alpha_A \log(|A|)$, $\quad \displaystyle v(\underline{\alpha})=\sum_{A\subseteq [5], A\neq \emptyset} \alpha_A$, $\quad$ and $\quad \displaystyle E(\underline{\alpha})=\sum_{ {A,B}: A\cap B\neq \emptyset} \alpha_A \alpha_B$,
where the sum for $E(\underline{\alpha})$ is taken over all unordered pairs of disjoint nonempty sets $A$ and $B$, where $A, B \subseteq [5]$.
Also define $FEAS(1/4)$ to be the set of all such vectors $\underline{\alpha}$ with nonnegative real entries such that $v(\underline{\alpha})=1$ and $E(\underline{\alpha})\geq 1/4$.
I want to learn how to program the following optimization problem:
$$\displaystyle OPT(1/4):=\max_{\underline{\alpha} \in FEAS(1/4)} OBJ(\underline{\alpha})$$
I was told that I can do this in SageMath. I have some basic knowledge of how to use Sage. How could I create the set $FEAS(1/4)$? I think that from there I may be able to figure out how to maximize $OBJ(\underline{\alpha})$ over this set.merluzaTue, 05 Nov 2019 22:28:50 +0100https://ask.sagemath.org/question/48630/