Demo calculation spatial interpolation
This tutorial shows how to develop a simple calculation and deploy it to Nexus so that it can run real time on the incoming data stream.
Info
This tutorial assumes that you have:
- Python installed on your computer
- Docker Desktop installed on your computer
- a Nexus account with Expert privileges
Let's develop a simple calculation in Python¶
Instead of starting from scratch, we're going to use a simple code already developed for you as an example. Download the demo code here and unzip the file on your computer.
Open a command prompt or terminal and navigate to the directory where you unzipped the file. Then install required packages:
pip install -r requirements.txt
Next, open your favorite code editor and edit the file config.py. Enter the developer credentials you received
by email for variables DB_USER, DB_PASSWORD and WEB_API_TOKEN.
Then inspect the file called main.py. What's happening here is that we fetch for each weather station the
precipitation sum for the current year, after which this sum is interpolated between the weather stations' locations
using the 'inverse distance' algorithm. This operation produces a raster in a Geotiff file, which we upload to
Nexus Datastore for storage and visualization.
Deploy it to Nexus¶
If we want to run this calculation every day, using the latest meteorological measurements, we should deploy the calculation to Nexus.
To deploy your calculation, open a command prompt or terminal and make sure you are navigated to the calculation directory. Then execute the following command:
deploy demo_interpolation {web_api_token}
Run it in the cloud¶
When the calculation is ready and deployed for operational use, email StellaSpark to activate it and have it executed every time the input data changes or on a fixed timed interval (for example every day, every hour or whatever fits your need).