Re: problem with region_ind function

Hi Mary,

Thanks for the response. You're right, the input file as I just realized
actually cuts off right in the range of longitudes I want to cut out with
region_ind. So I can only choose a range of latitudes that go to the edge
of the map on the east, and then again from the west edge of the map. Hope
that makes sense! It works now when I do this.

Thanks!
Mira

> Hi Mira,
>
> It appears that you are doing everything correctly. But, without your data
> file, I don't know how the lat/lons are spaced.
>
> Also, depending on what type of 2D grid you have, "region_ind" may not be
> appropriate.
>
> Can you provide the file?
>
> --Mary
>
> On Jul 11, 2013, at 10:20 AM, Mira Berdahl <mberdahl@envsci.rutgers.edu>
> wrote:
>
>> 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?
>> Thanks in advance,
>> Mira
>>
>> ;************************************************
>> ; NA_tos.ncl
>> ;************************************************
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/popRemap.ncl"
>> ;************************************************
>> begin
>>
>>
>> ;%%%%% read CCSM4 data%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>> in = addfile("tos_Omon_CCSM4_past1000_r1i1p1_110001-134912.nc","r")
>>
>> 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 %%%%%%%%%%%%%%%%
>> in = addfile("areacello_fx_CCSM4_past1000_r0i0p0.nc","r")
>>
>> 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
>> Copyright (C) 1995-2009 - All Rights Reserved
>> 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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>

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Received on Fri Jul 12 11:08:52 2013