Some data are cyclical and it can be helpful to calculate an optimal sine curve fit to the data (e.g., average daily temperature) for development of standards or models. This calculation feature provides that functionality. After selecting the desired data, the Calculate New Data form will appear:
As with other Calculate tools, you must specify the PCodes, CCode, and destination table. In addition, you must select the desired period in days and exceedance probability (50% for best fit through the data, and other percentages for confidence limits). Then a non-linear solution fit to the data is performed and the results are displayed:
A graph of the resulting fit looks like this:
