A commmand-line program to create a scatter-plot from an input csv data file, where the independent variable (x-axis) is expressed in dates like 2018-04-15.
You'll need to have Python v3 installed, plus the matplotlib library. To install matplotlib, use your OS's package manager; on Debian, that's:
apt install python3-matplotlib
X-axis (date) data goes in the first column (and must be formatted like YYYY-MM-DD). Y-axis data in the second column. The titles for the plot's axes will come from the first row of the csv.
For example:
Date,Height (cm)
2018-01-18,45
2018-01-22,48
2018-02-06,50
2018-02-07,52
2018-02-12,56
would produce:
Run it like so:
scatter-plot-by-date.py 'My Plot Title' input.csv
This will cause a window to pop up containing your plot. You'll usually then click the nostalgic floppy disk icon to save your plot to a file.