Summary to Distributing annual data across months

A big thanks needs to go out to Jaison, Ansley, and Mick as well as all of the rest of you who responded to my emails regarding "do loops" and "distributing annual data across months."

The Question:

I am trying to manipulate two files, one has annual data for 100 years (ann_var). The other has monthly data for 1 year (norm_var which is created from the NC file I read in). I want to distribute the 100 annual values over 12 months such that the value for each month in a year is the same as the annual value (a total of twelve hundred values). For the second file I want to distribute the monthly values over the 100 years such that the value for January in year one is the same as January in year 100.

Mick Spillane suggested the following code for distributing annual data values across months. The example uses 3 years and 36 months.

! define grid for three years annual data
def axis/t=1-jul-2001:1-jul-2003/npoints=3 tyear
def grid/t=tyear gyear

! and load it with sample data {2,3,1}
let vsample=tsequence({2,3,1})
let vyear=vsample[g=gyear,gt=@asn]
list vyear
JUL-2001 / 1: 2.000
JUL-2002 / 2: 3.000
JUL-2003 / 3: 1.000

! now define grid for the monthly data
def axis/t=15-jan-2001:15-dec-2003/npoints=36 tmonth
def grid/t=tmonth gmonth

! now we need a "sample" function with 36 values: 12x1, 12x2, 12x3
let lsamp = int((l[g=gmonth]-1)/12) + 1

! which used with the SAMPLEL gives us what we need
let vm=samplel(vyear,lsamp) ! this has the values right but
! lacks the calendar axis
let vmonth=vm[g=gmonth,gt=@asn]
list vmonth
15-JAN-2001 / 1: 2.000
14-FEB-2001 / 2: 2.000
.
.
14-JAN-2002 / 13: 3.000
14-FEB-2002 / 14: 3.000
.
14-JAN-2003 / 25: 1.000
14-FEB-2003 / 26: 1.000

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As for the second problem distributing monthly values over 100 years such that the value for a single month is the same in every year, I borrowed some code from the "how to create a climatology" and advice from Jaison and Ansley.

! define axis and grid
!-----------------------------
define axis/t="15-jan-2001:12:00":"15-dec-2100:12:00"/np=1200 t1200
set axis/modulo t1200
define grid/x=lon/y=lat/t=t1200 gt1200

14-JAN-2080 / 1: 19.00
14-FEB-2080 / 2: 23.60
15-MAR-2080 / 3: 10.00
14-APR-2080 / 4: -2.70
15-MAY-2080 / 5: -10.00
14-JUN-2080 / 6: -17.20
15-JUL-2080 / 7: -6.30
14-AUG-2080 / 8: -7.40
14-SEP-2080 / 9: -11.40
14-OCT-2080 / 10: 1.50
14-NOV-2080 / 11: 12.60
14-DEC-2080 / 12: 29.00

! Get the climatological_axis
!----------------------------
use climatological_axes
cancel data climatological_axes
! Get rid of the Year
!----------------------------
let new_var = var[gt=month_reg@mod]
list new_var

16-JAN      / 1: 19.00
15-FEB      / 2: 23.60
17-MAR      / 3: 10.00
16-APR      / 4: -2.70
16-MAY      / 5: -10.00
16-JUN      / 6: -17.20
16-JUL      / 7: -6.30
16-AUG      / 8: -7.40
15-SEP      / 9: -11.40
16-OCT      / 10:   1.50
15-NOV      / 11: 12.60
16-DEC      / 12: 29.00

! Set up the new grid to map monthly values onto
! (there probably is a more elagant solution)
!----------------------------
let temp = 0*x[gx=lon] + 0*y[gy=lat] + 0*t[gt=t1200]

! Regrid the monthly values across all 100 years
!----------------------------
let final_var = temp + new_var[gt=t1200@asn]
list final_var

15-JAN-2001 / 1: 19.00
14-FEB-2001 / 2: 23.60
.
.
15-JAN-2002 / 13: 19.00
14-FEB-2002 / 14: 23.60
.
.
14-JAN-2100 / 1189: 19.00
14-FEB-2100 / 1190: 23.60
.
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Once again a big thanks to Jaison, Ansley, Mick, and everyone else who took the time to help me get this!

Barry B. Baker, Ph.D. Climate Change Modeler bbaker@tnc.org (303) 541-0322 (Phone) (303) 449-4328 (Fax) nature.org\tncscience\scientists\misc\baker.html		The Nature Conservancy Global Climate Change Initiative 2424 Spruce Street Suite 100 Boulder, CO 80302 nature.org
"A reverence for uncertainty is one of the unrecognized implications of systems thinking" Peter Senge