assignment-2018-1

1st Assignment

Intro

This program finds the optimal path of a graph.

It also calculates the path that a person will get, influenced by the present bias (Behavioral Economics).

A few words about the Present Bias

Suppose we have a graph beginning with s and ending with t.

The available paths from point s to point t are as follows:

• s-a-b-t at a cost of 16+2+2 = 20
• s-c-d-t at a cost of 8+8+8 = 24
• s-c-e-t at a cost of 8+2+16 = 26

The person who is influenced by the present bias, when he is in a node, estimates the cost of the nodes adjacent to the node with a cost degraded by a factor of b<1 and so the cost is:

With b=1/2 the person will take:

1. At the beginning of the node you calculate the cost of the paths:

   • s-a-b-t at a cost of 16+(1/2)*2+(1/2)*2 = 20
   • s-c-d-t at a cost of 8+(1/2)*8+(1/2)*8 = 24
   • s-c-e-t at a cost of 8+(1/2)*2+(1/2)*16 = 26

   and selects the node c

2. Starting from node c, calculates:

   • c-d-t at a cost of 8+(1/2)*8 = 12
   • c-e-t at a cost of 2+(1/2)*16 = 10

   and selects the node e

Based on factor b the person will choose s-c-e-t at a cost of 26.

Description

The purpose of the program is, given a graph and a parameter b, to calculate the optimal path and path that a person will be affected by present bias. Parameter b is referred to present bias, and b<1.

The process of executing the program is:

1. Clone the repository
2. cd ../assignment-2018-1
3. Type python present_bias.py <input_file> <bias_parameter> <start_node> <end_node>
   • input_file The file name which include the graph (see the examples example_1 | example_2 | example_3.
   • bias_parameter The parameter b
   • start_node The starting node for example "s"
   • end_node The ending node for example "e"