[gradsusr] help displaying from netcdf file

Tue Jun 19 00:51:16 EDT 2012

You can try just a single data file first without template option.

On Tue, Jun 19, 2012 at 12:44 PM, Jeff Duda <jeffduda319 at gmail.com> wrote:
> Eric,
> Thanks for your suggestion.  I removed "byteswapped" and the headerbytes
> option from my control file, but unfortunately that did not solve the
> problem.  Any other ideas?
>
> Jeff
>
>
> On Mon, Jun 18, 2012 at 10:24 PM, Eric Altshuler <ela at cola.iges.org> wrote:
>>
>> Jeff,
>>
>> For netcdf data, the 'byteswapped' and 'headerbytes' options are
>> meaningless. The netcdf format is independent of byte ordering and there are
>> always some extra bytes for the metadata. Try removing the byteswapped
>> option and the headerbytes entry.
>>
>> Best regards,
>>
>> Eric L. Altshuler
>> Assistant Research Scientist
>> Center for Ocean-Land-Atmosphere Studies
>> 4041 Powder Mill Road, Suite 302
>> Calverton, MD 20705-3106
>> USA
>>
>> E-mail: ela at cola.iges.org
>> Phone: (301) 902-1257
>> Fax: (301) 595-9793
>>
>> ----- Original Message -----
>> From: "Jeff Duda" <jeffduda319 at gmail.com>
>> To: "GrADS Users Forum" <gradsusr at gradsusr.org>
>> Sent: Monday, June 18, 2012 3:22:33 PM
>> Subject: [gradsusr] help displaying from netcdf file
>>
>>
>> I'm trying to use Grads to display data from a netCDF file. The result of
>> ncdump for that file is
>>
>> ncdump -h ARW_cn_20110427.nettemp2m079200
>> netcdf ARW_cn_20110427 {
>> dimensions:
>> x = 1163 ;
>> y = 723 ;
>> z = 1 ;
>> variables:
>> float temp2m(z, y, x) ;
>> temp2m:standard_name = "temp2m" ;
>> temp2m:long_name = "temp2m" ;
>> temp2m:units = "F" ;
>> }
>>
>> The file size is 3363608 bytes. Given the data are floating point and
>> single precision, the size of the data alone are 1163*723*4 = 3363396, for a
>> difference of 212 bytes
>>
>> I made a control file designed to open several hundred individual files to
>> display the variable temp2m:
>> dset s4%e_arw/ARW_%e_20110427.nettemp2m%ch
>> chsub 1 1 003600
>> chsub 2 2 007200
>> chsub 3 3 010800
>> chsub 4 4 014400
>> chsub 5 5 018000
>> chsub 6 6 021600
>> chsub 7 7 025200
>> chsub 8 8 028800
>> chsub 9 9 032400
>> chsub 10 10 036000
>> chsub 11 11 039600
>> chsub 12 12 043200
>> chsub 13 13 046800
>> chsub 14 14 050400
>> chsub 15 15 054000
>> chsub 16 16 057600
>> chsub 17 17 061200
>> chsub 18 18 064800
>> chsub 19 19 068400
>> chsub 20 20 072000
>> chsub 21 21 075600
>> chsub 22 22 079200
>> chsub 23 23 082800
>> chsub 24 24 086400
>> chsub 25 25 090000
>> chsub 26 26 093600
>> chsub 27 27 097200
>> chsub 28 28 100800
>> chsub 29 29 104400
>> chsub 30 30 108000
>> chsub 31 31 111600
>> chsub 32 32 115200
>> chsub 33 33 118800
>> chsub 34 34 122400
>> chsub 35 35 126000
>> chsub 36 36 129600
>> options template byteswapped
>> undef -9999.0
>> dtype netcdf
>> pdef 1163 723 lcc 23.2231 -119.145 1.0 1.0 38.5 38.5 -97.0000 4000.000
>> 4000.000
>> xdef 1163 linear -128.1065 0.053758
>> ydef 723 linear 23.2231 0.040388
>> zdef 1 linear 1.0 1.0
>> tdef 36 linear 01Z27APR2011 1HR
>> edef 10 NAMES cn m21 m23 m24 m25 m26 m27 m28 m29 m30
>> VARS 1
>> temp2m 1 y,x 2-m temperature (F)
>> ENDVARS
>> headerbytes 212
>>
>> When attempting to display the variable in Grads, I get this output:
>> ga-> open SSEF_ens_temp2m_20110427_net.ctl
>> Scanning description file: SSEF_ens_temp2m_20110427_net.ctl
>> Data file s4%e_arw/ARW_%e_20110427.nettemp2m%ch is open as file 1
>> LON set to -128.107 -65.6397
>> LAT set to 23.2231 52.3832
>> LEV set to 1 1
>> Time values set: 2011:4:27:1 2011:4:27:1
>> E set to 1 1
>> Notice: Implied interpolation for file SSEF_ens_temp2m_20110427_net.ctl
>> Interpolation will be performed on any data displayed from this file
>> ga-> d temp2m
>> Notice: Automatic Grid Interpolation Taking Place
>> NetCDF Error (gancrow, nc_get_vara_double): NetCDF: Index exceeds
>> dimension bound
>> Data Request Error: Error for variable 'temp2m'
>> Error ocurred at column 1
>> DISPLAY error: Invalid expression
>> Expression = temp2m
>>
>> I have also tried altering the line
>> temp2m 1 y,x 2-m temperature (F)
>> by the line
>> temp2m 1 z,y,x 2-m temperature (F)
>> in accordance with the output from ncdump. No avail.
>>
>> Please help me determine the reason for this error and how to fix it.
>> Thanks.
>>
>> Jeff Duda
>> --
>> Jeff Duda
>> Graduate research assistant
>> University of Oklahoma School of Meteorology
>> Center for Analysis and Prediction of Storms
>>
>>
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>
>
>
>
> --
> Jeff Duda
> Graduate research assistant
> University of Oklahoma School of Meteorology
> Center for Analysis and Prediction of Storms
>
>
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> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>

-- 
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Dr. Yaqiang Wang
Chinese Academy of Meteorological Sciences (CAMS)
46, Zhong-Guan-Cun South Avenue
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China

yaqiang.wang at gmail.com

http://www.meteothinker.com
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