point_distance.py

Calculate distances between points in a CSV

Usage

python point_distance.py path_to_csv

If invalid data or duplicate point IDs are encountered, they will simply be ignored - check the command line output for warnings.

Requirements:

• Python 2.7

Input:

CSV containing point id, x, y coordinate columns:

id	x	y
1	0	0
2	0	1
3	0	2
4	0	5
5	0	10

All ID's must be unique whole numbers; all coordinates must be whole numbers or decimal

Output:

CSV containing a matrix displaying distances between points will be created in the current working directory

id	1	2	3	4	5
1	0	1	2	5	10
2	1	0	1	4	9
3	2	1	0	3	8
4	5	4	3	0	5
5	10	9	8	5	0
(Note - you get decimals as an output, not just integers like in this table)

Assumptions

• Input CSV is comma delimited
• IDs are unique and mandatory
• Values in coordinate fields are numeric (i.e. no exponential notation present)
• It is acceptable to ignore erroneous points (duplicate IDs, non-numeric values)

Testing

python test_point_distance.py

• Tests the critical function point_distance multiple times which calculates distance between points.

• Tests the function load_csv_rows which imports the data from CSV, ignoring faulty data.

• Tests the function create_matrix which creates the final matrix containing distances calculated between points