[Octave-bug-tracker] [bug #42353] ncread reading data incorrectly

[Muhali]

URL:
  <http://savannah.gnu.org/bugs/?42353>

                 Summary: ncread reading data incorrectly
                 Project: GNU Octave
            Submitted by: muhali
            Submitted on: Wed 14 May 2014 05:21:30 AM PDT
                Category: Octave Forge Package
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: dev
        Operating System: GNU/Linux

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Details:

The following  example illustrates that ncread reads data incorrect:


pkg load netcdf
url =
"http://www.esrl.noaa.gov/psd/thredds/dodsC/Datasets/udel.airt.precip/precip.mon.total.v301.nc";
x = ncread(url, "precip",[1 1 1], [720 360 1], [1 1 1]);
xm = max(x(:))
max(x(x~=xm))


which gives xm = 3276.7 and max(x(x~=xm)) = 99.5. The latter value is the
correct maximum, as one can test with other netcdf packages (e.g. cdo).

I suspect that the error occurs because the missing value


undef = ncinfo(file).Variables(4).Attributes(3)


is not recognized as such; it is an int16 variable with value 32767, which
after scaling results in the maximum value of 3276.7.




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