Re: [ferret_users] defining time axis

["Ansley C. Manke" <ansley.b.manke@xxxxxxxx>]

There is not a particular way to capture the details of a few months' average per year in the data model for time axes. The axis will just be one grid point per year. But there are a number of ways to define a yearly axis.

If you want  a listing of the time coordinates to be

 2001, 2002, 2003

then the axis that you have defined is fine, and a listing will just depend on the formatting of the listing that you are using. 

If you want to compare with other data which may be, say, monthly data in those years, then Ferret can do that comparison, and you might use this definition:

yes? define axis/t=0:11:1/t0=15-apr-2001/units=years tyear

Where I have put the coordinate location for each at the middle of April. Showing the axis points,

yes? list t[gt=tyear]
             VARIABLE : T
                        axis TYEAR
             SUBSET   : 12 points (TIME)
 APR-2001 /  1:   0.00
 APR-2002 /  2:   1.00
 APR-2003 /  3:   2.00
 APR-2004 /  4:   3.00
 APR-2005 /  5:   4.00
 APR-2006 /  6:   5.00
 APR-2007 /  7:   6.00
 APR-2008 /  8:   7.00
 APR-2009 /  9:   8.00
 APR-2010 / 10:   9.00
 APR-2011 / 11:  10.00
 APR-2012 / 12:  11.00

You could work with data on that axis, and Ferret will automatically convert between it and other calendar axes, defined  in other time units such as days or months, and with different time origins.

Ansley

On 5/13/2016 11:15 AM, Arijeet Dutta wrote:

Hello Mr Ansley
Actually I have 11 data points for 11 years, they are averaged over
march,april and may months for each year from 2001 to 2011, so I have
11 points, now I want to put them in a time axis where only years will
be there from 2001 to 2011.

Regards
Arijeet








On 5/13/16, Ansley C. Manke <ansley.b.manke@xxxxxxxx> wrote:

Hi,
To define a time axis that's treated as calendar time, you also need to
give it a time origin.

    DEFINE AXIS/T0=

-Ansley

On 5/12/2016 8:52 PM, Arijeet Dutta wrote:

Hi all
A small doubt. I am defining time axis as

define axis/t=2001:2011:1/units=years tyear
le var1=var[gt=tyear@asn]

time axis is showing years 2001.0, 2002.0 and so on. Why is this
decimal form coming and how to get rid of that?

Thanks
Arijeet