Thursday, January 28, 2021

Assignment problem with a wrinkle formulated as a network problem

›
In a previous post [1] I discussed a simple problem. But it turned out not so easy to solve for some of the larger data sets. Basically, it ...
5 comments:
Wednesday, January 27, 2021

An assignment problem with a wrinkle

›
In [1], the following problem is posed: Consider two arrays \(\color{darkblue}a_i\) (length \(\color{darkblue}m\)) and \(\color{darkblue}b_j...
16 comments:
Wednesday, January 20, 2021

Continuous max sum rectangle: MIQP vs GA

›
This is a follow-up on the post on the max sum submatrix problem [1].  There we looked at the problem of finding a contiguous submatrix th...
4 comments:
Tuesday, January 19, 2021

Submatrix with Largest Sum

›
Problem Given a data matrix \(\color{darkblue}a_{i,j}\), find a submatrix such that the sum of the elements is maximized . The term "s...
Wednesday, January 6, 2021

Eight soldiers lining up: a very large permutation problem

›
In [1] an intriguing problem is posted: There are 8 soldiers, gathering and lining up every morning for their military service. The commande...
Monday, January 4, 2021

Continuous Facility Location: Symmetry, SOCP and grid search

›
In this post, I consider the following question:  Given \(m\) consumer locations, what is the minimum number of facilities (warehouses)  nee...
1 comment:
Thursday, December 24, 2020

Numbrix puzzle via TSP

›
 In [1], I demonstrated a small and rather elegant MIP model to solve Numbrix puzzles. Here is the comment by Austin Buchanan: It would also...
2 comments:
Tuesday, December 22, 2020

Numbrix puzzle via MIP

›
The puzzle of numbrix [1,2] is simple to state. We have a 9x9 board with 81 cells.  We need to fill each cell with a unique integer value b...
3 comments:
Monday, December 21, 2020

GAMS + R Markdown scripting

›
In [1] I discussed a small script that exported GAMS data to R for plotting. Here I expand on that and show how we can use R Markdown [2] to...
Saturday, December 19, 2020

GAMS + R scripting

›
 I like to automate things. That means in practice: I write scripts. I prefer to spend a little more time to develop a script, basically for...
1 comment: