utinvcal.nc {RNetCDF}

Convert UTC Referenced Dates Into Temporal Amounts

Description

Convert a UTC referenced date into a temporal amount.

Usage

utinvcal.nc(unitstring, value)

Arguments

unitstring

A temporal unit with an origin (e.g., "days since 1900-01-01").

value

Dates to convert as a numeric vector or array, or a vector of strings or POSIXct values.

Details

Uses the UDUNITS library to convert a UTC-referenced date and time into the amount, value, of the temporal unit, unitstring.

If the dates are given in string form, the structure must be exactly "YYYY-MM-DD hh:mm:ss".

A vector of POSIXct values is also accepted as input. These are converted to the specified units by a linear transformation, without an intermediate separation into date components.

Value

A vector containing the amount(s) of the temporal unit(s) corresponding to the given date(s).

Author(s)

Pavel Michna, Milton Woods

References

https://www.unidata.ucar.edu/software/udunits/

See Also

utcal.nc

Examples

if (inherits(try(utcal.nc("seconds since 1970-01-01", 0)), "try-error")) {
  warning("UDUNITS calendar conversions not supported by this build of RNetCDF")

} else {

  ##  Convert UTC referenced time to other time units
  utinvcal.nc("hours since 1900-01-01 00:00:00 +01:00", c(1900,1,1,5,25,0))
  utinvcal.nc("hours since 1900-01-01 00:00:00 +01:00", "1900-01-01 05:25:00")
  utinvcal.nc("hours since 1900-01-01 00:00:00 +01:00", ISOdatetime(1900,1,1,5,25,0,tz="UTC"))

}

##  An example of reading and writing a netcdf time coordinate 
##  is given in the help for utcal.nc