clim_spread(data, clim_start, clim_end, windowHalfWidth)
The data given to this function during the calculations
The first day of the time series to use when spreading.
The last day of the time series to use when spreading.
The width of the smoothing window to be applied. This width is doubled and centred around the point that the smoothing occurs. Default = 5, which makes an overall window size of 11.
The function returns the data (a matrix) in a wide format.