Re: [ferret_users] Seasonal_reg regriding questions

["Oots, Penny C. (LARC-E301)[SCIENCE SYSTEMS AND APPLICATIONS, INC]" <penny.c.oots@xxxxxxxx>]

Ansley,

Is there a method for modifying the seasonal_reg axis to change it to
1-Dec to 1-Mar
1-Mar to 1-Jun
1-Jun to 1-Sep
1-Sep to 1-Dec

Ie shift the seasons to be DecJanFeb, MarAprMay, JunJulAug, Sep,Oct,Nov?

I believe this is what was being asked by another user also (see
http://www.pmel.noaa.gov/maillists/tmap/ferret_users/fu_2002/msg00378.html)
.

Penny Oots

On 12/5/12 2:14 PM, "Ansley Manke" <ansley.b.manke@xxxxxxxx> wrote:

>Hi Penny,
>Coordinate values are at the middle of the grid cell, so
>
>15-Feb runs from 1-Jan to 1-Apr
>15-May runs from 1-Apr to 1-Jul
>15-Aug runs from 1-Jul to 1-Oct
>15-Feb runs from 1-Jan to 31-Dec
>
>The command
>
>yes? show axis/t seasonal_reg
>
>lists the coordinates, the box sizes the date of the lower limit of the
>axis and the time step, or time coordinate value.  The definition of
>"month" is an ambiguous one, so in order for the grid cells to be evenly
>spaced, things aren't quite as clean as what I listed above.  The axis
>has four, equally spaced cells, each 1/4 year long.
>
>(Coordinate axes can actually lie anywhere in a grid cell, IF one
>specifies the edges of the cells as well as the coordinates, with the
>DEFINE AXIS/EDGES or DEFINE AXIS/BOUNDS qualifier and those edges are
>then saved in netCDF files. But that's not done on the climatological
>axes in the Ferret dataset climatological_axes.cdf)
>
>
>
>On 12/5/2012 9:50 AM, Oots, Penny C. (LARC-E301)[SCIENCE SYSTEMS AND
>APPLICATIONS, INC] wrote:
>> I created a netcdf file by regridding a threads aggregation of monthly
>>data with
>> time values of integer number of months since 2006-06-01 (i.e. Time
>>values are
>> 7.0 to 66.0) to a seasonal_reg axis.   The resulting time axis has the
>>following
>> values (in hours) that correspond to Feb-15, May-15, Aug-15, and Nov 15.
>>
>> SEASONAL_REG[4]
>> 1095.7275, 3287.1825, 5478.6375, 7670.0925
>>
>>
>> yes? show axis seasonal_reg
>>   name       axis              # pts   start                end
>>   SEASONAL_REG TIME              4mr   15-FEB 15:43         15-NOV 14:05
>> T0 =3D 01-JAN-0000 00:00:00
>>     Axis span (to cell edges) =3D 8765.82 (modulo length =3D axis span)
>>
>> Question 1:  Does Feb 15 represent data from Feb 15 to May-15 or from
>>Jan-15 to Apr-15?  (Is Feb 15 the mid-point or the beginning point?)
>>
>> And does Nov 15 represent data from Nov 15 to Feb 15 or from Oct 15 to
>>Dec 15?
>>
>> And is there a Ferret command that I should have found to display this
>>info?
>>
>> Question 2:  Why is the 15th of the month used instead of the first of
>>the month?
>>
>> Penny Oots
>>
>>
>>
>>
>