[gradsusr] xdfopen netcdf

Qian, JianHua JianHua_Qian at uml.edu
Fri May 31 16:24:11 EDT 2013


Or how to build a xdfopen descriptor file for netcdf data of daily u winds:
uwnd.1979.nc, uwnd.1980.nc, … ?

Joshua

From: Jianhua Qian <Jianhua_Qian at uml.edu<mailto:Jianhua_Qian at uml.edu>>
Date: Fri, 31 May 2013 16:13:26 -0400
To: GrADS Users Forum <gradsusr at gradsusr.org<mailto:gradsusr at gradsusr.org>>
Cc: Jianhua Qian <Jianhua_Qian at uml.edu<mailto:Jianhua_Qian at uml.edu>>
Subject: Re: [gradsusr] xdfopen netcdf

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<mailto:jma at cola.iges.org>>
Reply-To: GrADS Users Forum <gradsusr at gradsusr.org<mailto:gradsusr at gradsusr.org>>
Date: Fri, 31 May 2013 13:06:03 -0400
To: GrADS Users Forum <gradsusr at gradsusr.org<mailto: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<mailto:jma at cola.iges.org>>
Reply-To: GrADS Users Forum <gradsusr at gradsusr.org<mailto:gradsusr at gradsusr.org>>
Date: Fri, 31 May 2013 07:35:39 -0400
To: GrADS Users Forum <gradsusr at gradsusr.org<mailto: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<mailto:hui.wang at noaa.gov>>
Reply-To: GrADS Users Forum <gradsusr at gradsusr.org<mailto:gradsusr at gradsusr.org>>
Date: Thu, 30 May 2013 23:44:24 -0400
To: GrADS Users Forum <gradsusr at gradsusr.org<mailto: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<mailto: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<http://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<http://uwnd.1979.nc/>
uwnd.1980.nc<http://uwnd.1980.nc/>
…
When I do ncdump uwnd.1979.nc<http://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<mailto:gradsusr at gradsusr.org>
http://gradsusr.org/mailman/listinfo/gradsusr


_______________________________________________ gradsusr mailing list gradsusr at gradsusr.org<mailto:gradsusr at gradsusr.org> http://gradsusr.org/mailman/listinfo/gradsusr
_______________________________________________
gradsusr mailing list
gradsusr at gradsusr.org<mailto: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<mailto:jma at cola.iges.org>



_______________________________________________ gradsusr mailing list gradsusr at gradsusr.org<mailto:gradsusr at gradsusr.org> http://gradsusr.org/mailman/listinfo/gradsusr
_______________________________________________
gradsusr mailing list
gradsusr at gradsusr.org<mailto: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<mailto:jma at cola.iges.org>



_______________________________________________ gradsusr mailing list gradsusr at gradsusr.org<mailto:gradsusr at gradsusr.org> http://gradsusr.org/mailman/listinfo/gradsusr
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://gradsusr.org/pipermail/gradsusr/attachments/20130531/a3831d17/attachment-0003.html 


More information about the gradsusr mailing list