549: Seasonal Statistics
When the Y file contains monthly or daily data, CPT will calculate a seasonal aggregate depending upon the type of variable in the Y files. CPT will calculate a seasonal average from the monthly or daily data if the Y data represent temperatures or precipitation rates (the average is weighted by the lengths of each month), or a seasonal total if the Y data represent counts or precipitation accumulations. Specifically, the method of aggregation is set depending upon the cpt:units tag. If the units are:
- 'K', 'Kelvin_scale', 'C', 'degree_Celsius', 'Celsius_scale', 'F', 'Farenheit'
- 'm/s', 'meters/second', 'm s-1', 'mm/day', 'cm/day'
- 'counts'
- 'm', 'meters', 'cm', 'mm', 'mm/month'
Additional aggregation options are available and will apply if the Y data are daily. These additional options require the setting of a threshold, t:
- counts below the threshold (i.e., the number of days with values lower than t);
- counts above the threshold (i.e., the number of days with values greater than t);
- occurrence below the threshold (i.e., a 1 if any of the days have values lower than t, and a 0 otherwise);
- occurrence above the threshold (i.e., a 1 if any of the days have values greater than t, and a 0 otherwise).