make_whole_fast {heatwaveR}

Constructs a continuous, uninterrupted time series of temperatures (faster).

Description

Takes a series of dates and temperatures, and if irregular (but ordered), inserts missing dates and fills correpsonding temperatures with NAs.

Usage

make_whole_fast(data)

Arguments

data

A data frame with columns for date (ts_x) and temperature (ts_y) data. Ordered daily data are expected, and although missing values (NA) can be accommodated, the function is only recommended when NAs occur infrequently, preferably at no more than three consecutive days.

Details

1. This function reads in daily data with the time vector specified as Date (e.g. "1982-01-01").

2. It is up to the user to calculate daily data from sub-daily measurements. Leap years are automatically accommodated by this function.

3. This function can handle some missing days, but this is not a licence to actually use these data for the detection of anomalous thermal events. Hobday et al. (2016) recommend gaps of no more than 3 days, which may be adjusted by setting the maxPadLength argument of the ts2clm function. The longer and more frequent the gaps become the lower the fidelity of the annual climatology and threshold that can be calculated, which will not only have repercussions for the accuracy at which the event metrics can be determined, but also for the number of events that can be detected.

4. The original make_whole tests to see if some rows are duplicated, or if replicate temperature measurements are present per day. In make_whole_fast (this function) this has been disabled; also, the latter function lacks the facility to check if the time series is complete and regular (i.e. no missing values in the date vector). Effectively, we now only set up the day-of-year (doy) vector in make_whole_fast. Should the user be concerned about the potential for repeated measurements or worry that the time series is irregular, we suggest that the necessary checks and fixes are implemented prior to feeding the time series to ts2clim via make_whole_fast, or to use make_whole instead. For very large gridded temperature records it probably makes a measurable difference if the 'fast' version is used, but it might prevent detect_event from failing should some gridded cells contain missing rows or some duplicated values. When using the fast algorithm, we assume that the user has done all the necessary work to ensure that the time vector is regular and without repeated measurements beforehand.

Value

The function will return a data frame with three columns. The column headed doy (day-of-year) is the Julian day running from 1 to 366, but modified so that the day-of-year series for non-leap-years runs 1...59 and then 61...366. For leap years the 60th day is February 29. The ts_x column is a series of dates of class Date, while y is the measured variable. This time series will be uninterrupted and continuous daily values between the first and last dates of the input data.

Author(s)

Smit, A. J., Schlegel, R. W.