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Add a time component to input

add_time_to_weather_data.Rd

Ensure, if possible, that input data that varies over time has a "time" component. See the documentation for time for more information about this quantity.

It is rare for users to call this function directly because it is called internally by run_biocro.

Usage

add_time_to_weather_data(drivers)

Arguments

drivers

A list or dataframe representing known system parameters that vary over time, such as weather data.

Value

If drivers has doy and hour columns, then it is assumed to represent weather data, and will be modified as follows:

  • A new time column will be computed from doy and hour.

  • The original doy and hour columns will be removed.

In this case, it is expected that the BioCro:format_time direct module will be used to re-compute doy and hour from time.

If drivers does not have doy and hour columns, then drivers will be returned as-is.

Note

Preconditions:

  • If drivers is a list, the values should be vectors of equal length.

  • If drivers already contains a time component, then it shouldn't contain either a doy or an hour component unless it contains both of them and the values are mutually consistent.

Why is the 'BioCro:format_time' module necessary?

If values of doy and hour are supplied to run_biocro in the drivers, undesired results may happen during interpolation. For example, if two sequential rows have (time = 3599, doy = 150, hour = 23) and (time = 3600, doy = 151, hour = 0), and the results are to be returned at half-hour time intervals, then linear interpolation between these rows would produce (time = 3599.5, doy = 150.5, hour = 11.5). Typically it is expected that doy takes only integer values, so this may cause issues. Using the BioCro:format_time module to calculate doy and hour from time will ensure that the result includes (time = 3599.5, doy = 150, hour = 23.5) instead.

Examples

  # Add a time column to the buit-in 2002 weather data
  new_weather <- add_time_to_weather_data(weather[['2002']])

  # Compare column names
  colnames(weather[['2002']])
#> [1] "year"             "doy"              "hour"             "time_zone_offset"
#> [5] "precip"           "rh"               "solar"            "temp"            
#> [9] "windspeed"       
  colnames(new_weather)
#> [1] "year"             "time_zone_offset" "precip"           "rh"              
#> [5] "solar"            "temp"             "windspeed"        "time"