# [ncl-talk] averaging over non-consecutive, user-inputted times

mberdahl at envsci.rutgers.edu mberdahl at envsci.rutgers.edu
Thu Jun 4 20:05:20 MDT 2015

```Hi all,

I have downloaded NCEP reanalysis winds (u and v), each with dimensions
[time x lat x long].  The data runs from 1948 - current.  I take the DJF
seasonal average first.  Next, I am trying to take an average of
user-inputted, non-consecutive years.  So for example, I'd like to take
the average over, say, 1958, 1967, 1999 and 2001.  I have used
dim_avg_n_wrap to do averages before, but as far as I can see I can only
choose a range of consecutive years with this.  Is there a simple way to
do this?  Also, I manually convert the years to indices, but not sure
that's the way to go.

My code and some of the VarSummaries are copied here.  I run into an error
when trying to make a list of years at line 43
(uDJF_NAO_lo = uDJF((10,11,12,16,24,26,43,44,57,58),:,:))

Thanks!
Mira

;****************************************************
;************************************************
begin
;************************************************
;************************************************
print(a)

;************************************************
; read in zonal [u] and meridional [v] winds (July)
;************************************************

u = a->uwnd(0:803,{45:90},{270:357.5})
v = b->vwnd(0:803,{45:90},{270:357.5}) ; Get u, v, time (1),level
(1000hpa),latitude(-90:90) and longitude(0:360) data.

printVarSummary(u)
printVarSummary(v)

; Calculate the seasonal averages.
uDJF = month_to_season(u, "DJF")
vDJF = month_to_season(v, "DJF")

printVarSummary(uDJF)
printVarSummary(vDJF)

; I want to average over these years.
; yearList_lo = 1963        1964        1965        1969        1977
1979        1996        1997        2010        2011
; this data starts at 1948 (this is index 0), so 1953=5, 1963=10 etc.

uDJF_NAO_lo = uDJF((10,11,12,16,24,26,43,44,57,58),:,:)

;************************************************
; create plot
;************************************************
wks = gsn_open_wks("ps","vector_") ; open a ps file

vcres = True ; plot mods desired
vcres at gsnFrame = False ; so we can draw time stamp
vcres at vcRefAnnoOrthogonalPosF = -1.0 ; move ref vector up
vcres at vcRefMagnitudeF = 10.0 ; define vector ref mag
vcres at vcRefLengthF = 0.045 ; define length of vec ref
vcres at vcGlyphStyle = "CurlyVector" ; turn on curly vectors
vcres at vcMinDistanceF = 0.017

;************************************************
; Choose a subregion
;************************************************
vcres at mpFillOn = False ; turn off gray fill
vcres at mpOutlineBoundarySets = "National" ; turn on country boundaries
vcres at mpGeophysicalLineColor = "Navy" ; color of cont. outlines
vcres at mpGeophysicalLineThicknessF = 1.5 ; thickness of outlines

vcres at mpMaxLatF = 90 ;maximum latitude
vcres at mpMinLatF = 45 ;minimum latitude
vcres at mpMaxLonF = 357.5 ;maximum longitude
vcres at mpMinLonF = 270 ;minimum longitude

vector = gsn_csm_vector_map_ce(wks,uAvgTime,vAvgTime,vcres)

frame (wks)
end

*************************************************************

Converted to chunked, deflated non-packed NetCDF4 2014/09
title : monthly mean uwnd.sig995 from the NCEP Reanalysis
dimensions:
lat = 73
lon = 144
time = 808  // unlimited
variables:
float lat ( lat )
units :        degrees_north
actual_range : ( 90, -90 )
long_name :    Latitude
standard_name :        latitude
axis : Y

float lon ( lon )
units :        degrees_east
long_name :    Longitude
actual_range : (  0, 357.5 )
standard_name :        longitude
axis : X

double time ( time )
long_name :    Time
delta_t :      0000-01-00 00:00:00
prev_avg_period :      0000-00-01 00:00:00
standard_name :        time
axis : T
units :        hours since 1800-01-01 00:00:0.0
actual_range : ( 1297320, 1886808 )

float uwnd ( time, lat, lon )
long_name :    Monthly Mean Zonal Wind at sigma level 0.995
valid_range :  ( -102.2, 102.2 )
units :        m/s
scale_factor :  1
missing_value :        -9.96921e+36
precision :    2
least_significant_digit :      1
var_desc :     u-wind
dataset :      CDC Derived NCEP Reanalysis Products
level_desc :   Surface
statistic :    Mean
parent_stat :  Other
actual_range : ( -18.83935, 18.80581 )
_FillValue :   -9.96921e+36

Variable: u
Type: float
Total Size: 2199744 bytes
549936 values
Number of Dimensions: 3
Dimensions and sizes:   [time | 804] x [lat | 19] x [lon | 36]
Coordinates:
time: [1297320..1883904]
lat: [45..90]
lon: [270..357.5]
Number Of Attributes: 15
long_name :   Monthly Mean Zonal Wind at sigma level 0.995
valid_range : ( -102.2, 102.2 )
units :       m/s
scale_factor :         1
missing_value :       -9.96921e+36
precision :   2
least_significant_digit :     1
var_desc :    u-wind
dataset :     CDC Derived NCEP Reanalysis Products
level_desc :  Surface
statistic :   Mean
parent_stat : Other
actual_range :        ( -18.83935, 18.80581 )
_FillValue :  -9.96921e+36

Variable: v
Type: float
Total Size: 2199744 bytes
549936 values
Number of Dimensions: 3
Dimensions and sizes:   [time | 804] x [lat | 19] x [lon | 36]
Coordinates:
time: [1297320..1883904]
lat: [45..90]
lon: [270..357.5]
Number Of Attributes: 15
long_name :   Monthly Mean Meridional Wind at sigma level 0.995
valid_range : ( -102.2, 102.2 )
units :       m/s
scale_factor :         1
missing_value :       -9.96921e+36
precision :   2
least_significant_digit :     1
var_desc :    v-wind
dataset :     CDC Derived NCEP Reanalysis Products
level_desc :  Surface
statistic :   Mean
parent_stat : Other
actual_range :        ( -15.43516, 19.79167 )
_FillValue :  -9.96921e+36

Variable: uDJF
Type: float
Total Size: 183312 bytes
45828 values
Number of Dimensions: 3
Dimensions and sizes:   [time | 67] x [lat | 19] x [lon | 36]
Coordinates:
time: [1297320..1875888]
lat: [45..90]
lon: [270..357.5]
Number Of Attributes: 16
long_name :   DJF: Monthly Mean Zonal Wind at sigma level 0.995
valid_range : ( -102.2, 102.2 )
units :       m/s
scale_factor :         1
missing_value :       -9.96921e+36
precision :   2
least_significant_digit :     1
var_desc :    u-wind
dataset :     CDC Derived NCEP Reanalysis Products
level_desc :  Surface
statistic :   Mean
parent_stat : Other
actual_range :        ( -18.83935, 18.80581 )
_FillValue :  -9.96921e+36
NMO : 0

Variable: vDJF
Type: float
Total Size: 183312 bytes
45828 values
Number of Dimensions: 3
Dimensions and sizes:   [time | 67] x [lat | 19] x [lon | 36]
Coordinates:
time: [1297320..1875888]
lat: [45..90]
lon: [270..357.5]
Number Of Attributes: 16
long_name :   DJF: Monthly Mean Meridional Wind at sigma level 0.995
valid_range : ( -102.2, 102.2 )
units :       m/s
scale_factor :         1
missing_value :       -9.96921e+36
precision :   2
least_significant_digit :     1
var_desc :    v-wind
dataset :     CDC Derived NCEP Reanalysis Products
level_desc :  Surface
statistic :   Mean
parent_stat : Other
actual_range :        ( -15.43516, 19.79167 )
_FillValue :  -9.96921e+36

```