# problem with region_ind function

From: Mira Berdahl <mberdahl_at_nyahnyahspammersnyahnyah>
Date: Thu Jul 11 2013 - 10:20:27 MDT

Hi,

I am trying to subset a region in the North Atlantic from an ocean grid
with 2d lat and lon. I am following example 1 here:
http://www.ncl.ucar.edu/Document/Functions/Contributed/region_ind.shtml

However, when I output the subsetted lat/lon range, it does not match the
range I request in the script (below).

Does anyone see why this might be?
Mira

;************************************************
; NA_tos.ncl
;************************************************
;************************************************
begin

;%%%%% read CCSM4 data%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

glat2d = in->lat
glon2d = in->lon

printMinMax(glat2d,True)
printMinMax(glon2d,True)

; region to subset
latS = 50 ; North Atlantic
latN = 65
lonW = 310
lonE = 340

ji = region_ind(glat2d, glon2d,latS,latN,lonW,lonE)

jStrt = ji(0) ; lat start
jLast = ji(1) ; lat last
iStrt = ji(2) ; lon start
iLast = ji(3) ; lon last

LAT2D = glat2d(jStrt:jLast,iStrt:iLast)
LON2D = glon2d(jStrt:jLast,iStrt:iLast)

printMinMax(LAT2D,True)
printMinMax(LON2D,True)

; read data just for the region fo interest
x_1100_1350 = in->tos(:,jStrt:jLast,iStrt:iLast)

printVarSummary(x_1100_1350)

;%%%%% read in the weights (area of grid cells %%%%%%%%%%%%%%%%

x_area = in->areacello(jStrt:jLast,iStrt:iLast)
printVarSummary(x_area)

;%%% calculate the area weighted NA temperature --- based on area of grid
cells.
NA_tos_ccsm4_1100_1350 = wgt_areaave2(x_1100_1350 ,x_area,0)

asciiwrite("NA.tos.ccsm4.1100.1350.asc",NA_tos_ccsm4_1100_1350)

end

[mlosic@ncoeus Ocean]\$ ncl testing_ccsm4.ncl
University Corporation for Atmospheric Research
NCAR Command Language Version 5.1.0
The use of this software is governed by a License Agreement.
See http://www.ncl.ucar.edu/ for more details.
(0)
(0)glat2d: latitude coordinate: min=-79.2205 max=89.7064
(0)
(0)glon2d: longitude coordinate: min=0.0147311 max=359.996
(0)
(0)LAT2D: latitude coordinate: min=49.7087 max=89.1075
(0)
(0)LON2D: longitude coordinate: min=0.0155527 max=359.974

Variable: x_1100_1350
Type: float
Total Size: 153600000 bytes
38400000 values
Number of Dimensions: 3
Dimensions and sizes: [time | 3000] x [j | 40] x [i | 320]
Coordinates:
time: [401515..492734.5]
j: [327..366]
i: [1..320]
Number Of Attributes: 13
standard_name : sea_surface_temperature
long_name : Sea Surface Temperature
comment : TEMP at topmost level, units from C to K,
CMIP5_table_comment: "this may differ from ""surface temperature"" in
regions of sea ice."
units : K
original_name : TEMP
original_units : degC
history : 2012-03-13T22:34:24Z altered by CMOR: Converted units from
'degC' to 'K'. 2012-03-13T22:34:24Z altered by CMOR: replaced missing
value flag (9.96921e+36) with standard missing value (1e+20).
cell_methods : time: mean (interval: 30 days)
cell_measures : area: areacello
missing_value : 1e+20
_FillValue : 1e+20
associated_files : baseURL:
http://cmip-pcmdi.llnl.gov/CMIP5/dataLocation gridspecFile:
gridspec_ocean_fx_CCSM4_past1000_r0i0p0.nc areacello:
areacello_fx_CCSM4_past1000_r0i0p0.nc
coordinates : lat lon

Variable: x_area
Type: float
Total Size: 51200 bytes
12800 values
Number of Dimensions: 2
Dimensions and sizes: [j | 40] x [i | 320]
Coordinates:
j: [327..366]
i: [1..320]
Number Of Attributes: 11
standard_name : cell_area
long_name : Ocean Grid-Cell Area
units : m2
original_name : TAREA
comment : TAREA convert cm2 to m2
original_units : centimeter^2
history : 2012-02-02T18:54:47Z altered by CMOR: Converted units from
'centimeter^2' to 'm2'. 2012-02-02T18:54:47Z altered by CMOR: replaced
missing value flag (9.96921e+36) with standard missing value (1e+20).
missing_value : 1e+20
_FillValue : 1e+20
associated_files : baseURL:
http://cmip-pcmdi.llnl.gov/CMIP5/dataLocation gridspecFile:
gridspec_ocean_fx_CCSM4_past1000_r0i0p0.nc
coordinates : lat lon

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Received on Thu Jul 11 10:20:45 2013

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