NCL Website header
NCL Home > Documentation > Functions > Date routines

yyyymmddhh_to_yyyyfrac

Converts a one-dimensional array containing yyyymmddhh values to yyyy and fractional year.

Prototype

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"  ; This library is automatically loaded
                                                             ; from NCL V6.2.0 onward.
                                                             ; No need for user to explicitly load.

	function yyyymmddhh_to_yyyyfrac (
		yyyymmddhh [*] : integer, float, double,  
		hh_offset  [1] : float, double            
	)

Arguments

yyyymmddhh

A one dimensional array containing yyyymmddhh values: yyyy are years (Gregorian); "mm" are months ranging from 1 to 12 corresponding to January to December; the "dd" are calendar day of the month [1 to 31]; the "hh" indicate integer hours spanning [0 to 23].

hh_offset

Currently not used. Set to zero.

Return value

A one-dimensional array containing values of the form yyyy plus fractional part of year. If yyyymmddhh is type double the return will be type double. Otherwise type float is returned.

Description

For each value of yyyymmddhh, the day_of_year is determined. The fractional part is determined by calculating the number of seconds from Jan 1 at zero hours to each yyyymmddhh value. That number is divided by the numbers of days in the year [365 or 366] times 86400 seconds.

See Also

List of "date" and "calendar" functions

Examples

The following require that contributed.ncl be loaded prior to invoking the function.

       load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"

Example 1

Convert a 1D array to yyyy plus fractional part of year.

      yyyymmddhh = (/ 1979010100 , 1979010106, 1979010112, 1979010118  /)      

      yrfrac = yyyymmddhh_to_yyyyfrac(yyyymmddhh, 0)
      print(yrfrac) 
Each of the above yields a 1D array of length 4 values.
(0)     1979
(1)     1979.000685
(2)     1979.001370      
(3)     1979.002055