Re: [ferret_users] Calculating monthly mean from NOLEAP daily mean

[Jian Ma <jianma@xxxxxxxxxx>]

Hi Ansley,

Thanks.

Maybe I did not state clear my purpose. It is a multi-year daily data
and I want to make a multi-year monthly mean, not climatology. Then how
can I define the days count for Noleap calendar?

Many thanks again,
Tony

On Thu, 2011-07-28 at 09:30 -0700, Ansley Manke wrote:
> Hi Tony,
> The problem you face is that the days1900 function uses the default 
> calendar, not the NOLEAP one.
> 
> The climatological_axes dataset contains a monthly NOLEAP climatological 
> axis called MONTH_NOLEAP, so you can just use that.
> 
> yes? use climatological_axes
>   *** NOTE: regarding 
> /home/users/tmap/ferret/linux/go/climatological_axes.cdf ...
>   *** NOTE: Climatological axes SEASONAL_REG, MONTH_REG, MONTH_IRREG, 
> MONTH_GREGORIAN, MONTH_NOLEAP, MONTH_360_DAY  defined
> 
> yes? list t[gt=MONTH_NOLEAP], tboxlo[gt=MONTH_NOLEAP], 
> tboxhi[gt=MONTH_NOLEAP]
>               TIME: 01-JAN 00:00 to 01-JAN 00:00 NOLEAP
>   Column  1: T is T (axis MONTH_NOLEAP)
>   Column  2: TBOXLO is TBOXLO (axis MONTH_NOLEAP)
>   Column  3: TBOXHI is TBOXHI (axis MONTH_NOLEAP)
>                           T  TBOXLO TBOXHI
> 16-JAN 12      /  1:   15.5    0.0   31.0
> 15-FEB 00      /  2:   45.0   31.0   59.0
> 16-MAR 12      /  3:   74.5   59.0   90.0
> 16-APR 00      /  4:  105.0   90.0  120.0
> 16-MAY 12      /  5:  135.5  120.0  151.0
> 16-JUN 00      /  6:  166.0  151.0  18100005a01-0010     /  7:  196.5  181.0  212.0
> 16-AUG 12      /  8:  227.5  212.0  243.0
> 16-SEP 00      /  9:  258.0  243.0  273.0
> 16-OCT 12      / 10:  288.5  273.0  304.0
> 16-NOV 00      / 11:  319.0  304.0  334.0
> 16-DEC 12      / 12:  349.5  334.0  365.0
> 
> 
> On 7/27/2011 6:45 PM, Jian Ma wrote:
> > Hi All,
> >
> > I am using the function days1900 to calculate monthly mean from NOLEAP
> > daily mean. There is an error in time axis definition. Days1900 are
> > giving Julian days from 1900. If I use the following definition, the
> > time is wrong, due to different day count between the calendars.
> >
> > DEFINE AXIS/UNITS=days/T0=1-jan-1900/EDGES/cal=noleap truemonth =
> > DAYS1900(year,month,1)
> >
> > Anyone has a good method to calculate NOLEAP days from 1900? Or do I
> > have to do a NOLEAP ->  Julian transformation
> >
> > Many thanks,
> > Tony
> >