Hui Du,
Why you didn't email cdcdata@xxxxxxxx, like the readme says, I don't know.
The data are packed, per Unidata NetCDF convention. See:
http://www.cdc.noaa.gov/PublicData/faq.html#2
-Hoop
> From owner-ncdigest@xxxxxxxxxxxxxxxx Tue May 4 21:42:59 2004
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> ncdigest Tuesday, May 4 2004 Volume 01 : Number 766
>
>
>
> Today's Topics:
> Problems with reading my data
>
> ----------------------------------------------------------------------
>
> Date: Tue, 04 May 2004 14:02:10 -0700
> From: "Hui Du" <netcdf@xxxxxxxxxxx>
> Subject: Problems with reading my data
>
> >Dear netcdf users:
> >> I am trying to read data from a netcdf file. But it turned out crazy
> >> The following are some of the data I have read
> >> -1.3207933E+10
> >> -8.3823027E+09
> >> -5.4078728E+11
> >> -1.6477924E+12
> >> -3.1043398E+17
> >> -1.3207933E+10
> >> -1.0523522E+10
> >> -8.1099614E+11
> >> -2.6932095E+11
> >>They are completely different from what I expect. Actually , the Data
> >>should be the following or something
> >>
> >>-12310, -12320, -12315, -12310, -12310, -12320, -12325, -12340, -123
> >>40,
> >> -12340, -12345, -12350, -12350, -12354, -12360, -12365, -12370, -123
> >>75,
> >> -12379, -12395, -12410, -12415, -12420, -12425, -12425, -12420, -124
> >>04,
> >> -12400, -12395, -12385, -12375,
> >>
> >>When I use the same fortran program to read another different fille, it
> >>works well. The only modification I made is changing the dimension size
> >>
> >>the following is the fortran program, I think it should be right
> >>********************************************************
> >> program filter
> >> parameter (ndims=4)
> >> parameter (nlat=73,nlon=144)
> >> real data(nlon,nlat)
> >> integer ncid,ncidin,ncidout,iv
> >> integer rcode
> >> integer start(3), count(3)
> >> data start/1,1,1/
> >> data count/nlon,nlat,1/
> >> character*50 fname
> >> character*20 file
> >> include '/opt/netcdf/include/netcdf.inc'
> >> ncidin = ncopn('../obs_cdc_olr.ctrl.nc',ncnowrit,rcode)
> >> iv=4
> >> k=1
> >> call rdncdf2d(ncidin,iv,k,data)
> >> do i=1,5
> >> do j=1,5
> >> write(6,*) data(i,j)
> >> end do
> >> end do
> >> stop
> >> end
> >>
> >>subroutine rdncdf2d(ncidin,id,itime,data)
> >> parameter (nlat=73, nlon=144)
> >> parameter (ndims=3)
> >> integer rcode
> >> integer start(ndims), count(ndims)
> >> real data(nlon,nlat)
> >> character*31 dimname
> >> data start/1,1,1/
> >> data count/nlon,nlat,1/
> >> start(3)=itime
> >> call ncvgt(ncidin,id,start,count,data,rcode)
> >> return
> >> end
> >>***********************************************************
> >>
> >>There are some difference between these two file in that one has scale
> >>factor and offset, the other does not. The following is the part of the
> >>head information of the two netcdf files
> >>
> >>for obs_cdc_olr.ctrl.nc (for this file where the problem happened)
> >> short olr(time, lat, lon) ;
> >> olr:long_name = "Daily OLR" ;
> >> olr:valid_range = 0.f, 500.f ;
> >> olr:actual_range = 64.75f, 341.9f ;
> >> olr:units = "W/m^2" ;
> >> olr:add_offset = 327.65f ;
> >> olr:scale_factor = 0.01f ;
> >> olr:missing_value = 32766s ;
> >> olr:var_desc = "Outgoing Longwave Radiation\n",
> >> "O" ;
> >> olr:precision = 2s ;
> >> olr:dataset = "NOAA Interpolated OLR\n",
> >> "O" ;
> >> olr:level_desc = "Other\n",
> >> "-" ;
> >> olr:statistic = "Mean\n",
> >> "M" ;
> >> olr:parent_stat = "Individual Obs\n",
> >> "I" ;
> >>
> >>for mm5_lon180_ncep.ctrl.nc (for this file it works well)
> >>
> >> float LWOUTNEW(TDAY, LATITUDE110_28, LONGITUDE17_80) ;
> >> LWOUTNEW:missing_value = -1.e+34f ;
> >> LWOUTNEW:_FillValue = -1.e+34f ;
> >> LWOUTNEW:long_name = "outgoing longwave radiation" ;
> >> LWOUTNEW:units = "W m^-2" ;
> >>
> >>
> >>Would anyone give me some hint about this problem?
> >>Thanks a lot in advance !
> >>
> >>Hui Du
>
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> ------------------------------
>
> End of ncdigest V1 #766
> ***********************
