[gradsusr] xdfopen netcdf (Jennifer Adams)
Qian, JianHua
JianHua_Qian at uml.edu
Sun Jun 2 22:39:59 EDT 2013
Dear Hoop,
I followed your instruction and the following works:
sdfopent uwnd.1979.nc uwnd.%y4.nc 10958
Thanks!
Joshua
On 6/1/13 10:19 PM, "Hoop" <hoop at Colorado.EDU> wrote:
>JianHua Qian,
>
>The URL Jennifer gave has a link on it for writing
>xdfopen-style DDFs:
>
>http://iges.org/grads/gadoc/gradcomdxdfopen.html
>
>Also, run the sdfopent script on your files. In
>addition to leaving you ready to deal with your
>time series of data, it writes a 3-line xdfopen-
>style DDF and opens it for you. So, you can look
>at that file for a working example. To see how
>to use sdfopent, just run it once without arguments.
>
>-Hoop
>
>On 05/31/2013 09:45 PM, Qian, JianHua wrote:
>> Dear Hoop,
>>
>> Sorry that I ignored your early email about sdfopent.
>> I do not know how to build a 3-line DDF.
>>
>> My data is the daily u-winds of the NCEP reanalysis:
>> uwnd.1979.nc (365 days)
>> uwnd.1980.nc (366 days, leap year)
>> uwnd.1981.nc (365 days)
>> Š
>> uwnd.2008.nc (366 days, leap year)
>>
>> How to build the xdfopen-style data descriptor file (DDF) for these
>> datasets.
>> Please correct my following is my draft:
>>
>> dset uwnd.%y4.nc
>> templ template
>> ntimes 10958 (note: this is the total number of days from 1979
>> to 2008)
>>
>>
>> Thanks!
>> Joshua
>>
>>
>>
>> On 5/31/13 5:37 PM, "Hoop"<hoop at colorado.edu> wrote:
>>
>>> All true, however, one needn't go to this much trouble. First of all,
>>> the xdfopen-style data descriptor file (DDF) is only three lines long
>>> to accomplish this templating. Secondly, as I mentioned earlier this
>>> week, the GrADS script "sdfopent", in the standard GrADS script
>>>library:
>>>
>>> http://grads.iges.org/grads/gadoc/library.html
>>> ftp://cola.gmu.edu/grads/scripts/sdfopent.gs
>>>
>>> not only saves you the bother of writing any DDF, since it replicates
>>> the old three argument syntax for doing templating on the sdfopen
>>>command,
>>> it also gives you a working example of such a three-line DDF, as what
>>>the
>>> script does is compose the XDFopen-style DDF and then open it for you.
>>>
>>> Of course, when I mentioned sdfopent earlier this week, I was soundly
>>> ignored, and I expect the same will occur this time.
>>>
>>> -Hoop
>>>
>>> On 05/31/13 15:20, gradsusr-request at gradsusr.org wrote:
>>>> Date: Fri, 31 May 2013 17:20:48 -0400
>>>> From: Jennifer Adams<jma at cola.iges.org>
>>>> Subject: Re: [gradsusr] xdfopen netcdf
>>>> To: GrADS Users Forum<gradsusr at gradsusr.org>
>>>> Message-ID:<9387B97A-9537-405A-9F3B-31054B4EEB67 at cola.iges.org>
>>>> Content-Type: text/plain; charset="windows-1252"
>>>>
>>>> The data are packed. See the documentation for the UNPACK keyword
>>>> which will need the names of the attributes that contain the
>>>> scale factor and add offset.
>>>> http://iges.org/grads/gadoc/SDFdescriptorfile.html
>>>> --Jennifer
>>>>
>>>> On May 31, 2013, at 4:13 PM, Qian, JianHua wrote:
>>>>
>>>>> Jennifer,
>>>>>
>>>>> Thanks! I got the file opened, but the value of u wind is incorrect.
>>>>> When I use sdfopen uwnd.1979.nc, d uwnd, I got:
>>>>> ga-> sdfopen uwnd.1979.nc
>>>>> Scanning self-describing file: uwnd.1979.nc
>>>>> SDF file uwnd.1979.nc is open as file 1
>>>>> LON set to 0 360
>>>>> LAT set to -90 90
>>>>> LEV set to 1000 1000
>>>>> Time values set: 1979:1:1:0 1979:1:1:0
>>>>> E set to 1 1
>>>>> ga-> d uwnd
>>>>> Contouring: -15 to 15 interval 5
>>>>>
>>>>> However, when I use open uwnd_3d_day_79_08.ctl
>>>>> D uwnd, I got something different:
>>>>>
>>>>> ga-> open uwnd_3d_day_79_08.ctl
>>>>> Scanning description file: uwnd_3d_day_79_08.ctl
>>>>> Data file uwnd.%y4.nc is open as file 1
>>>>> LON set to 0 360
>>>>> LAT set to -90 90
>>>>> LEV set to 1000 1000
>>>>> Time values set: 1979:1:1:0 1979:1:1:0
>>>>> E set to 1 1
>>>>> ga-> d uwnd
>>>>> Contouring: -20500 to -17000 interval 500
>>>>>
>>>>> I tried to add options big_endian or little_endian, and still got
>>>>> unrealistic values such as
>>>>> Contouring: -20500 to -17000 interval 500
>>>>>
>>>>> The following is my ctl file:
>>>>>
>>>>> dset ^uwnd.%y4.nc
>>>>> dtype netcdf
>>>>> title 3-D NCEP-DOE uwnd 1jan1979 to 31dec2008
>>>>> options little_endian template yrev
>>>>> undef -1.e+34
>>>>> xdef 144 linear 0.0 2.5
>>>>> ydef 73 linear -90.0 2.5
>>>>> zdef 17 levels 1000 925 850 700 600 500 400 300 250 200 150 100 70 50
>>>>> 30 20 10
>>>>> tdef 10958 linear 00z01jan1979 24hr
>>>>> vars 1
>>>>> uwnd 17 t,z,y,x m/s
>>>>> Endvars
>>>>>
>>>>> Could you help to check the problem?
>>>>>
>>>>> Thanks!
>>>>> Joshua
>>>>>
>>>>> From: Jennifer Adams<jma at cola.iges.org>
>>>>> Reply-To: GrADS Users Forum<gradsusr at gradsusr.org>
>>>>> Date: Fri, 31 May 2013 13:06:03 -0400
>>>>> To: GrADS Users Forum<gradsusr at gradsusr.org>
>>>>> Subject: Re: [gradsusr] xdfopen netcdf
>>>>>
>>>>> You can't have a negative increment.
>>>>> ydef 73 linear -90 2.5
>>>>>
>>>>> You may also need to add:
>>>>> options yrev
>>>>>
>>>>> --Jennifer
>>>>>
>>>>> On May 31, 2013, at 1:00 PM, Qian, JianHua wrote:
>>>>>
>>>>>> Jennifer,
>>>>>>
>>>>>> I used "open", but still have problem:
>>>>>>
>>>>>> ga-> open uwnd_3d_day_79_08.ctl
>>>>>> Scanning description file: uwnd_3d_day_79_08.ctl
>>>>>> Open Error: Missing or invalid dimension increment value
>>>>>> --> The invalid description file record is:
>>>>>> --> ydef 73 linear 90.0 -2.5
>>>>>> The data file was not opened.
>>>>>>
>>>>>> Thanks!
>>>>>> Joshua
>>>>>>
>>>>>> From: Jennifer Adams<jma at cola.iges.org>
>>>>>> Reply-To: GrADS Users Forum<gradsusr at gradsusr.org>
>>>>>> Date: Fri, 31 May 2013 07:35:39 -0400
>>>>>> To: GrADS Users Forum<gradsusr at gradsusr.org>
>>>>>> Subject: Re: [gradsusr] xdfopen netcdf
>>>>>>
>>>>>> You have written a full descriptor file, so use 'open' instead of
>>>>>> 'xdfopen'. --Jennifer
>>>>>>
>>>>>> On May 31, 2013, at 7:05 AM, Qian, JianHua wrote:
>>>>>>
>>>>>>> Hui and Grads Users, thanks!
>>>>>>> But after I added "options template", I still got the same error
>>>>>>> message:
>>>>>>>
>>>>>>> ga-> xdfopen uwnd_3d_day_79_08.ctl
>>>>>>> Scanning Descriptor File: uwnd_3d_day_79_08.ctl
>>>>>>> gadxdf error: Missing or invalid dimension size.
>>>>>>> --> The invalid description file record is:
>>>>>>> --> xdef 144 linear 0.0 2.5
>>>>>>> The data file was not opened.
>>>>>>>
>>>>>>> Now my ctl file is as follows:
>>>>>>>
>>>>>>> dset ^uwnd.%y4.nc
>>>>>>> dtype netcdf
>>>>>>> title 3-D NCEP-DOE uwnd 1jan1979 to 31dec2008
>>>>>>> options template
>>>>>>> undef -1.e+34
>>>>>>> xdef 144 linear 0.0 2.5
>>>>>>> ydef 73 linear 90.0 -2.5
>>>>>>> zdef 17 levels 1000 925 850 700 600 500 400 300 250 200 150 100 70
>>>>>>> 50 30 20 10
>>>>>>> tdef 10958 linear 00z01jan1979 24hr
>>>>>>> vars 1
>>>>>>> uwnd 17 t,z,y,x m/s
>>>>>>> Endvars
>>>>>>>
>>>>>>> I do not know what is wrong with my grads descriptor file.
>>>>>>>
>>>>>>> Thanks!
>>>>>>> Joshua
>>>>>>>
>>>>>>> From: Hui Wang - NOAA Affiliate<hui.wang at noaa.gov>
>>>>>>> Reply-To: GrADS Users Forum<gradsusr at gradsusr.org>
>>>>>>> Date: Thu, 30 May 2013 23:44:24 -0400
>>>>>>> To: GrADS Users Forum<gradsusr at gradsusr.org>
>>>>>>> Subject: Re: [gradsusr] xdfopen netcdf
>>>>>>>
>>>>>>> Hi Joshua,
>>>>>>>
>>>>>>> I think you need to add "options template" in the ctl file.
>>>>>>>
>>>>>>> Good luck,
>>>>>>> Hui
>>>>>>>
>>>>>>> On Thu, May 30, 2013 at 10:32 PM, Qian, JianHua
>>>>>>> <JianHua_Qian at uml.edu> wrote:
>>>>>>> Grads Users,
>>>>>>>
>>>>>>> I got the following message when doing
>>>>>>> xdfopen uwnd_3d_day_79_08.ctl
>>>>>>>
>>>>>>> ga-> xdfopen uwnd_3d_day_79_08.ctl
>>>>>>> Scanning Descriptor File: uwnd_3d_day_79_08.ctl
>>>>>>> gadxdf error: Missing or invalid dimension size.
>>>>>>> --> The invalid description file record is:
>>>>>>> --> xdef 144 linear 0.0 2.5
>>>>>>> The data file was not opened.
>>>>>>>
>>>>>>> The descriptor file uwnd_3d_day_79_08.ctl is copied below:
>>>>>>>
>>>>>>> dset ^uwnd.%y4.nc
>>>>>>> dtype netcdf
>>>>>>> title 3-D NCEP-DOE uwnd 1jan1979 to 31dec2008
>>>>>>> undef -1.e+34
>>>>>>> xdef 144 linear 0.0 2.5
>>>>>>> ydef 73 linear 90.0 -2.5
>>>>>>> zdef 17 levels 1000 925 850 700 600 500 400 300 250 200 150 100 70
>>>>>>> 50 30 20 10
>>>>>>> tdef 10958 linear 00z01jan1979 24hr
>>>>>>> vars 1
>>>>>>> uwnd 17 t,z,y,x m/s
>>>>>>> Endvars
>>>>>>>
>>>>>>> The data files are in the current directory:
>>>>>>> uwnd.1979.nc
>>>>>>> uwnd.1980.nc
>>>>>>> ?
>>>>>>> When I do ncdump uwnd.1979.nc , I got:
>>>>>>> netcdf uwnd.1979 {
>>>>>>> dimensions:
>>>>>>> lon = 144 ;
>>>>>>> lat = 73 ;
>>>>>>> level = 17 ;
>>>>>>> time = UNLIMITED ; // (365 currently)
>>>>>>> nbnds = 2 ;
>>>>>>> variables:
>>>>>>> float level(level) ;
>>>>>>> level:units = "millibar" ;
>>>>>>> level:actual_range = 1000.f, 10.f ;
>>>>>>> level:long_name = "Level" ;
>>>>>>> level:positive = "down" ;
>>>>>>> level:GRIB_id = 100s ;
>>>>>>> level:GRIB_name = "hPa" ;
>>>>>>> level:axis = "z" ;
>>>>>>> level:coordinate_defines = "point" ;
>>>>>>> float lat(lat) ;
>>>>>>> lat:units = "degrees_north" ;
>>>>>>> lat:actual_range = 90.f, -90.f ;
>>>>>>> lat:long_name = "Latitude" ;
>>>>>>> lat:standard_name = "latitude_north" ;
>>>>>>> lat:axis = "y" ;
>>>>>>> lat:coordinate_defines = "point" ;
>>>>>>> float lon(lon) ;
>>>>>>> lon:units = "degrees_east" ;
>>>>>>> lon:long_name = "Longitude" ;
>>>>>>> lon:actual_range = 0.f, 357.5f ;
>>>>>>> lon:standard_name = "longitude_east" ;
>>>>>>> lon:axis = "x" ;
>>>>>>> lon:coordinate_defines = "point" ;
>>>>>>> double time(time) ;
>>>>>>> time:units = "hours since 1800-1-1 00:00:0.0" ;
>>>>>>> time:long_name = "Time" ;
>>>>>>> time:actual_range = 1569072., 1577808. ;
>>>>>>> time:delta_t = "0000-00-01 00:00:00" ;
>>>>>>> time:standard_name = "time" ;
>>>>>>> time:axis = "t" ;
>>>>>>> time:coordinate_defines = "start" ;
>>>>>>> time:avg_period = "0000-00-01 00:00:00" ;
>>>>>>> ?
>>>>>>> Could someone give me a clue?
>>>>>>>
>>>>>>> Thanks!
>>>>>>> Joshua
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> gradsusr mailing list
>>>>>>> gradsusr at gradsusr.org
>>>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>> gradsusr mailing list gradsusr at gradsusr.org
>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>>>> _______________________________________________
>>>>>>> gradsusr mailing list
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>>>>>>
>>>>>> --
>>>>>> Jennifer M. Adams
>>>>>> IGES/COLA
>>>>>> 4041 Powder Mill Road, Suite 302
>>>>>> Calverton, MD 20705
>>>>>> jma at cola.iges.org
>>>>>> _______________________________________________
>>>> gradsusr mailing list gradsusr at gradsusr.org
>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>>> _______________________________________________
>>>>>> gradsusr mailing list
>>>>>> gradsusr at gradsusr.org
>>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>>
>>>>> --
>>>>> Jennifer M. Adams
>>>>> IGES/COLA
>>>>> 4041 Powder Mill Road, Suite 302
>>>>> Calverton, MD 20705
>>>>> jma at cola.iges.org
>>>>> _______________________________________________
>>>> gradsusr mailing list gradsusr at gradsusr.org
>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>> _______________________________________________
>>>>> gradsusr mailing list
>>>>> gradsusr at gradsusr.org
>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>
>>>> --
>>>> Jennifer M. Adams
>>>> IGES/COLA
>>>> 4041 Powder Mill Road, Suite 302
>>>> Calverton, MD 20705
>>>> jma at cola.iges.org
>>>> _______________________________________________
>>>> gradsusr mailing list
>>>> gradsusr at gradsusr.org
>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>> _______________________________________________
>>> gradsusr mailing list
>>> gradsusr at gradsusr.org
>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>
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