Recent content by math8

How can price elasticity of demand for some data help in determining a decision making process in a future pricing policy? I have some data that I want to analyze. I am given prices and demand for different products over a period of time. And I would like to use the price elasticity data to get...

I have done 3 experiments. For each one of them, I have repeated the same experiment 100 times. Which gives me three sets of 100 numbers. Experiment 1: for number 30 ---> 100 results Experiment 2: for number 40 ---> 100 results Experiment 3: for number 50 ---> 100 results Basically, I...

In MATLAB, I am using fmincon to solve a minimization problem with nonlinear constraints. The problem is that, it is giving me a wrong answer, a point that is not a minimizer (not even close), and that is not within the tolerance. I made sure to use a feasible initial point. However, when I...

I have some results in Matlab which are mainly cell arrays and numbers. I want to save these results(either in a .txt file or anywhere else) so that I can use them later to make a table, draw a graph, etc... What is the best way to do that?

I am looking for jobs in the private sector (I might not be eligible for the government jobs). In the US. Do you know of any websites?

For Academia jobs, I used www.mathjobs.org, and it's quite good. I will have a degree in Applied-Mathematics (Numerical Optimization and Operation research). I am trying to apply for Industry jobs. However I am not sure how or where to apply. I heard the application process can be quite...

Thanks a lot.

hmm let see Let C = \{M(x) \cup J(x): M(x^*) \cup J(x^*) \subseteq M(x) \cup J(x) , x \in X \}. M(x^*)\cup J(x^*) \in C by the reflexive property of " is contained in or is equal to", so C is not empty. C is a set of subsets of a (disjoint union) of finite sets. So C contains a maximal...

I am trying to think about how I can use the finiteness of the index set I to show that there must be a special point \hat{x} such that M(\hat{x}) \supseteq M(x^*) . But I am not sure how to go about it. Can you give another hint?

I am also thinking about saying that the polytope X is compact, so if the set of "special points " is closed, then it is compact too. And then consider a sequence x_1, x_2, \cdots of special points such that M(x^*) \subseteq M(x_1)\subseteq M(x_2)\subseteq \cdots Then there exists a...

The f_i are defined on the polytope X and f_i(x) is a real number. j is an index in a finite index set. The a_j; b_j 's are just vectors with the same dimension as x . Your question makes me think about Zorn's Lemma which says that "Suppose a partially ordered set P has the property...

Let g(x)=max_{i=1,...,m} f_{i}(x) where f_{i} are continuous concave functions and let X = \{x: a_{j}^T x \geq b_{j} for j=1,\cdots, k \} be a polytope; M(x) = \{i: f_{i}(x) = g (x) \} and J(x) = \{j: a_{j}^T x = b_{j} \}. We define a "special" point to be a point \hat{x} for...

Thanks!

When I try to solve a linear program using matlab,after using linprog(f,A,b,...) I can find the Lagrange multiplier associated with the inequality constraints and the lower bound constraints by using: lambda.ineqlin ; lambda.lower But if I want to solve a quadratic program (using...

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