I think it's based on the plots they have on big storage freezers in in the biology world. These circular plotters are used because if there's a temperature sp

I think it's based on the plots they have on big storage freezers in in the biology world. These circular plotters are used because if there's a temperature spike (power failure etc.) at midnight for some reason you can see it next day by glancing at the plot. For this, they're basically just taking the normal temperature graph plot and wrapping it around a year over and over again. Mathematically, a switch to polar coordinates would be used I think.