[gradsusr] problem regarding opening data descriptor file in grads

[krishnamohan]

Hi Asmat,

I am using the following method to open GFDL netcdf files in grads. Suppose
you have an nc file named ua_A1_CM2_sresa2_r1_200101-210012.nc for u-wind,
then create a ctl file to read the data as


dset ^ua_A1_CM2_sresa2_r1_200101-210012.nc
TDEF time 1200 linear 16jan2001 1mo

don't forget to change time accordingly

and in grads use xdfopen to open the ctl file like

xdfopen uwnd.ctl , the data will be opened

Hope this will be useful for you

Regards

Krishnamohan


On Wed, Nov 27, 2013 at 1:37 PM, Jennifer Adams <jma at cola.iges.org> wrote:

>
> On Nov 27, 2013, at 7:07 AM, asmat ullah wrote:
>
> hi,
> i am using GFDL CM2.0...i have download the data form LAS portal of GFDL.
> i have run the .nc file than this error has been occurred as under..
>
> *SDF Error: 365 day calendars are no longer supported by sdfopen.*
> *To open this file with grads us a descriptor file with a complete TDEF
> entry and Options 365 day calendar……*
>
>
>
>
> than i use xconv and convert nc file in grads readable. this software give
> the output in two file one was .ctl file and .dat file. these file were not
> open properly when i gave the path in script of .ctl file by applying
> xdfopen, the error was as under….
>
> If you have a binary file and a descriptor file, then use 'open' not
> 'xdfopen'.
>
>
> *gadxdf error: invalid options keyword*
> *The invalid description file record is:*
> *options little_endian*
> *The data file was not opened.*
>
> In .ctl file the script was as under
> dset ^cm112.dat
> undef 200000004008175470000.000000
>
> This is a strange undef value. Should it be 2e20?
>
> options little_endian
>
> You only need this option if the endianness of the file is different from
> the endianness of the system on which you are reading it. Based on the
> error message you got from sdfopen, you should probably have a
> 365_day_calendar option here.
>
> *
> xdef 2 linear 1.000000 1.000000
> *
> ydef 1 linear 1 1
> *
> zdef 1 linear 1 1
> *
> tdef 264 linear 01:-3Z55 708dyhr
>
> This TDEF entry is undecipherable. Make sure you put the start time in the
> right format, something like 12z15jan2001. And the increment can have only
> one unit. Please see http://iges.org/grads/gadoc/descriptorfile.html#TDEF
>
> *
> vars 2
> TIME_bnds 0 99 TIME_bnds
> PR 0 99 Precipitation [kg m-2 s-1]
>
> GrADS wants lower case variable names. Change these to pr and time_bnds.
> --Jennifer
>
> endvars
>
>
> Please let me knw ho can i open .dat and .ctl files in grads, and how to
> operate .dat file in grads.
>
> Regards
> ASMAT ULLAH
>
>
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>
>
> --
> Jennifer M. Adams
> Center for Ocean-Land-Atmosphere Studies (COLA)
> 111 Research Hall, Mail Stop 2B3
> George Mason University
> 4400 University Drive
> Fairfax, VA 22030
>
>
>
>
>
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://gradsusr.org/pipermail/gradsusr/attachments/20131127/70e3bea6/attachment.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: uwnd.ctl
Type: application/octet-stream
Size: 78 bytes
Desc: not available
Url : http://gradsusr.org/pipermail/gradsusr/attachments/20131127/70e3bea6/attachment.obj