WebPlots Plot Generator

WebPlots is an Angular web application that runs scrips in Python and R to generate and present visualizations.

For examples of plotting scripts, see examples.md.

Libraries Supported

Python

1. Plotly
2. Matplotlib

R

1. Plotly
2. GGPlot2

Tech Stack

1. Angular
2. Docker
3. Flask
4. Plotly.js

Design Description

The backend runs a docker container that listens on routes /r_runner and /python_runner endpoints for POST requests and executes the contained script as a subprocess.

The output fromm the script is saved as a plotly figure, including conversions from other libraries if needed, and the link to the figure is sent as the response.

The frontend uses an iframe with a blank target at the start. This iframe is updated to the link from the backend when the response is recieved.

Issues Encontered

1. Scripts in R fail due to not being able to find common dataset libraries. Mitigated by pre-installing a wide array of libraries.
2. Matplotlib threw errors about having no graphical screen when plt.plot() was called. Solved by prepending matplotlib.use('Agg') in the script so that the non-graphical plotting backend is used.
3. Since the frontend and backend were running on the same host(localhost) but the servers were different, the Cross-Origin Resource Sharing (CORS) policy was blocking connections to the backend. This was solved by using the CORS module from flask.

Working Video

Screencast