Could not retrieve add offset. RH7.3
Willis, Paul ENV:EX
paul.willis at GOV.BC.CA
Wed May 24 14:35:49 EDT 2006
My posting below was premature. I am still experiencing the same problems
when attempting to use the TEMPLATE option with the DDF. Jennifer and
Diane have been kindly working with me off-listserve but without
resolution.
here is what I know:
My environment: linux RH7.3
GrADS install: I reinstalled with pre-compiled binary exe. no change.
Data file corruption: I downloaded a fresh set of data files. no change.
Hoop's 'sdfopen' merge: see previous thread. While this resolves the
offset and missing value warnings, the environment is unstable and core
dumps (segmentation faults) make it unworkable.
My questions du-jour:
1) Has anyone had compatibility problems running rh7.3?
2) Jennifer has 'grepped' GrADS source code and has not found the source
of this warning:
"-- using -1e+15 insteade data type for "missing_value"
Does this look familiar to anyone. note, I have not messed with the GrADS
source code on my machine.
3) Suggestions for further debugging of either the offset problem when
using the DDF, or with segmentation faults when using the 'sdfopen' merge?
Thanks.
Paul Willis
On Sun, 21 May 2006 01:25:35 +0200, Willis, Paul ENV:EX
<paul.willis at GOV.BC.CA> wrote:
>Jennifer, et al.,
>
>As it turns out, the original descriptor file that I sent was fine, as you
>and Diane have determined. Upon my debugging of another problem, I
>discovered I had incorrectly defined my $GADDIR environment variable. I
>have since tested the descriptor file without problem.
>
>I am a GrADS newbie and have a lot to learn. My apologies that you all
>spent some time on what turned out to be pilot error.
>
>By the way, I have successfully followed Hoop's 'sdfopen'. However, yes,
>I have experienced a number of core dumps. I am too inexperienced to make
>an assessment; could be nothing to do with this method and more to some
>other misconfiguration on my part. But I will try the two different
>methods over the course of the next two weeks and may have some comments
>of value.
>
>Thanks.
>
>-pw
>
>
>On Sat, 20 May 2006 16:14:58 -0400, Jennifer M. Adams <jma at COLA.IGES.ORG>
>wrote:
>
>>Dear Paul, et al.,
>>OK, so you could read this file with sdfopen and do it the way Hoop
>>suggests. But if templating with sdfopen often leads to core dumps on
>>your operating system, then it's perfectly reasonable to do it with a
>>'dtype netcdf' descriptor. User's choice. My greater concern is why
>>the 'dtype netcdf' interface isn't retrieving the 'add_offset' or the
>>'missing_value' attributes properly for you.
>>
>>I downloaded a NetCDF file from CDC -- daily means of SLP for 1999
>>with the identical ncdump output -- and used your descriptor file
>>with this data set and it read the slp data on my mac without any
>>problems at all:
>>
>>ga-> open /data/netcdf/rean/slp.ctl
>>Scanning description file: /data/netcdf/rean/slp.ctl
>>Data file /data/netcdf/rean/slp.%y4.nc is open as file 1
>>LON set to 0 360
>>LAT set to -90 90
>>LEV set to 1 1
>>Time values set: 1999:1:1:0 1999:1:1:0
>>ga-> q file
>>File 1 : NCEP Reanalysis Daily Averages
>> Descriptor: /data/netcdf/rean/slp.ctl
>> Binary: /data/netcdf/rean/slp.%y4.nc
>> Type = Gridded
>> Xsize = 144 Ysize = 73 Zsize = 1 Tsize = 731
>> Number of Variables = 1
>> slp 0 -103 mean Daily Sea Level Pressure [Pa]
>>ga-> d slp
>>Contouring: 97000 to 105000 interval 1000
>>ga->
>>
>>
>>The attributes of this file are exactly the same, so ... why doesn't
>>it work for you???
>>
>>On May 18, 2006, at 8:42 PM, Willis, Paul ENV:EX wrote:
>>> Running GrADS 1.9b4 on linux.
>>Which executable are you using: gradsnc, gradshdf, or gradsdods?
>>Which linux: RH7.1, RH9, or RHE3?
>>
>> Jennifer
>>
>>>
>>>
>>> Thanks in advance for any guidance.
>>>
>>> -paul
>>> *********************
>>>
>>>
>>> ga-> q dim
>>>
>>> Default file number is: 1
>>>
>>> X is varying Lon = 0 to 360 X = 1 to 145
>>>
>>> Y is varying Lat = -90 to 90 Y = 0.999999 to 73
>>>
>>> Z is fixed Lev = 1 Z = 1
>>>
>>> T is fixed Time = 00Z01JAN1999 T = 1
>>>
>>> ga-> d slp
>>> " -- using -1e+15 insteade data type for "missing_value
>>> " not handled
>>> -- using -1e+15 instead
>>>
>>> Warning: Could not retrieve add offset data type -- setting add
>>> offset to
>>> 0.0
>>>
>>> Contouring: -20000 to -16500
>>> interval 500
>>>
>>> *********************
>>> here is my descriptor file
>>> *********************
>>> dset /home/pfwillis/2006/Grads/circulation/Climate/data/slp_daily.%
>>> y4.nc
>>> dtype netcdf
>>> options yrev template
>>> undef -1e15 missing_value
>>> unpack scale_factor add_offset
>>> title NCEP Reanalysis Daily Averages
>>> xdef 144 linear 0 2.5
>>> ydef 73 linear -90 2.5
>>> zdef 1 linear 1 1
>>> tdef 731 linear 00Z01jan1999 24hr
>>> vars 1
>>> slp 0 t,y,x mean Daily Sea Level Pressure [Pa]
>>> endvars
>>>
>>>
>>> *********************
>>> should an ncdump provide useful information on this, see below.
>>> *********************
>>>
>>>
>>> netcdf slp_daily.1999 {
>>> dimensions:
>>> lon = 144 ;
>>> lat = 73 ;
>>> time = UNLIMITED ;
>>> // (365 currently)
>>> variables:
>>> float lat(lat) ;
>>> lat:units = "degrees_north" ;
>>>
>>> lat:actual_range = 90.f, -90.f ;
>>> lat:long_name = "Latitude" ;
>>>
>>> float lon(lon) ;
>>> lon:units = "degrees_east" ;
>>>
>>> lon:long_name = "Longitude" ;
>>>
>>> lon:actual_range = 0.f, 357.5f ;
>>> double time(time) ;
>>>
>>> time:units = "hours since 1-1-1 00:00:0.0" ;
>>>
>>> time:long_name = "Time" ;
>>> time:actual_range = 17514144., 17522880. ;
>>>
>>> time:delta_t = "0000-00-01 00:00:00" ;
>>>
>>> time:avg_period = "0000-00-01 00:00:00" ;
>>> short slp(time, lat, lon) ;
>>>
>>> slp:long_name = "mean Daily Sea Level Pressure" ;
>>>
>>> slp:valid_range = 87000.f, 115000.f ;
>>>
>>> slp:actual_range = 92970.f, 110552.f ;
>>>
>>> slp:units = "Pascals" ;
>>>
>>> slp:add_offset = 119765.f ;
>>>
>>> slp:scale_factor = 1.f ;
>>>
>>> slp:missing_value = 32766s ;
>>>
>>> slp:precision = 0s ;
>>>
>>> slp:least_significant_digit = -1s ;
>>>
>>> slp:GRIB_id = 2s ;
>>>
>>> slp:GRIB_name = "PRMSL" ;
>>>
>>> slp:var_desc = "Sea Level Pressure\n",
>>> "P" ;
>>>
>>> slp:dataset = "NCEP Reanalysis Daily Averages\n",
>>> "AJ" ;
>>>
>>> slp:level_desc = "Sea Level\n",
>>> "I" ;
>>>
>>> slp:statistic = "Mean\n",
>>> "M" ;
>>>
>>> slp:parent_stat = "Individual Obs\n",
>>> "I" ;
>>>
>>>
>>> // global attributes:
>>> :Conventions = "COARDS" ;
>>>
>>> :title = "mean daily NMC reanalysis (1999)" ;
>>>
>>> :base_date = 1999s, 1s, 1s ;
>>>
>>> :history = "created 99/01/04 by Hoop (netCDF2.3)" ;
>>>
>>> :description = "Data is from NMC initialized reanalysis\n",
>>>
>>> "(4x/day). It consists of most variables
>>> interpolated to\n",
>>>
>>> "pressure surfaces from model (sigma) surfaces." ;
>>>
>>> :platform = "Model" ;
>>>
>>>
>>> data:
>>>
>>> lat = .......
>>>
>>
>>Jennifer M. Adams
>>IGES/COLA
>>4041 Powder Mill Road, Suite 302
>>Beltsville, MD 20705
>>jma at cola.iges.org
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