Problems with reading my data

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: Problems with reading my data
• From: "Hui Du" <netcdf@xxxxxxxxxxx>
• Date: Tue, 04 May 2004 14:02:10 -0700

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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