# Linear and Integer Programming

A linear program is constituted of a linear objective function that models a profit to maximize or a cost to minimize, and a set of linear constraints that restrict decision variables. It has been the subject of very extensive research, and was given a major boost by Dantzig’s development of the Simplex method.

Mathematically, a linear program is formulated as:

Linear programming has many business and industrial applications in the fields of oil, finance, insurance, manufacturing, logistics, public transit and many more.

Some problems may require the use of all or some integer variables. These types of problems are difficult to solve optimally in a reasonable amount of time. Solving integer programs requires combining the simplex method and a branch and bound technique, often supplemented by domain reduction techniques (constraint programming), column generation or generation of cutting planes. …

# Use Dropbox as a Git Repo

It is pretty simple, all you need to do is create the base repo in your dropbox folder and push your code.

# Create a git project

`mkdir -p ~/myProject cd ~/myProject git init git add .`

# Create and setup the Dropbox base repo

`mkdir -p ~/Dropbox/Git cd ~/Dropbox/Git git init --bare myProject.git`

# Add the remote Dropbox folder

`cd ~/myProject git remote add origin ~/Dropbox/Git/myProject.git`

`echo >> "README.md" git add .git commit -m "first commit"`

# Push the code into the remote Dropbox

`git push -u origin master`

# gitdropbox: a script that creates a remote Dropbox repo

Here is a script that creates a new git project in `~/"new project"` and initializes a git repo on your Dropbox folder (`~/Dropbox/Git/"new project"`).

`gitdropbox myProject` will do all of the above in one command.

The script is available on github.com

## Usage

`mkdir ~/dev cd ~/devgit clone https://github.com/eddinho/gitdropbox.git sudo cp ~/dev/gitdropbox/gitdropbox /usr/local/bin/sudo chmod +x usr/local/bin/gitdropbox gitdropbox newProject`

Originally published at http://optalgo.com on January 1, 2020.

# Operations Research is helping to design better Public Transit: Understanding Planning

Did you know Operations Research is helping design better public transit ? It is helping to improve the quality of public transit and at the same time, help realize large savings.

• How many buses are needed ?
• Where should they be parked and at what time should they be sent to service the public?
• What territory should be covered, how many routes and where should be the bus stop and terminus?
• etc.

In fact, for decades new, public transit is providing interesting, complex and challenging Operations Research problems.

Operations Research can tackle such complex problems. Moreover, it is needed to optimize the use of resources, realize significant savings and produce solutions compliant with the laws, regulations and labor union contracts. …