nc_to_obj

nc_to_obj reads a netCDF file or a selection of channels of a netCDF file into a UniScript object.

obj = nc_to_obj(ssFilename)

obj = nc_to_obj(ncid)

obj = nc_to_obj(ssFilename, svChannelNames)

obj = nc_to_obj(ncid, svChannelNames)

Return Value

obj is an object containing the channels and three other objects: globals, channel_info and order. globals contains the global attributes of the netCDF file, channel_info contains the channel attributes for each channel and order contains the channel order of the netCDF file.

In case of an error, the function returns the value 0.

Parameters

ssFilename

ssFilename is the netCDF file name or any other data file. Other files will be converted to netCDF if possible.

ncid

ncid is the id of a UniPlot data file (see nc_open or nc_create). Use nc_close to close the file. Instead of ncid the file name ssFilename can be used.

svChannelNames

svChannelNames is a string vector with channel names (optional). If set to 0, a selection dialog box will be displayed.

Example

* ssFile = GetRootDirectory() + "samples/test1.xls";
* o = nc_to_obj(ssFile, ["EWGFAK", "Alpha"])
* o
[.
    Alpha = matrix 17 x 1 [88.7, 81.78, 82.76, 88.35, 88.7, ...]
    EWGFAK = matrix 17 x 1 [0.85, 0.86, 0.86, 0.87, 0.87, ...]
    channel_info = [.
        Alpha = [.
            C_format = "%.2lf"
            add_offset = 0
            datatype = "real4"
            long_name = "Alpha [-]"
            scale_factor = 1
            title = "Alpha"
            units = "-"
        ]
        EWGFAK = [.
            C_format = "%.2lf"
            add_offset = 0
            datatype = "real4"
            long_name = "EWGFAK [GRAD]"
            scale_factor = 1
            title = "EWGFAK"
            units = "GRAD"
        ]
    ]
    globals = [.
        Creator = "UniPlot Excel Converter v3"
        Origin = "d:\\uniplot_du\\samples/test1.xls"
        Source = "FEV Software and Testing Solutions GmbH (www.uniplot.de)"
        __XSort__ = 0
        columnseparator = "\\t"
        firstdatarow = 3
        missing_value = 1e+10
    ]
    order = [.
        [1] = "EWGFAK"
        [2] = "Alpha"
    ]
]
object (obj at 0x3400C14)

Example 2

Calculates the mean value of all selected NC files. The result is an NC file with mean channels. All channels must have the same number of data points. Only channel are calculated which are in the first data file.

RegisterCommand("NC File", "NC_CalculateMean", "NC-Mean...");
UserBar_Add("NC_CalculateMean");

def NC_CalculateMean()
{
   ssDir = "";
   bMultiselect = TRUE;
   bSortByDate = TRUE;
   bConvertToNC = TRUE;
   svFiles = GetOpenFileName_Data(ssDir, bMultiselect, bSortByDate, bConvertToNC)
   if (svFiles[1] == "") {
      return;
   }
   nFiles = len(svFiles);

   if (nFiles == 1) {
      return svFiles[1];
   }
   obj1 = nc_to_obj(svFiles[1]);
   svChannel = obj1.channel_info.keys("");
   obj1.globals.File1 = svFiles[1];
   for (i in 2:nFiles) {
      objn = nc_to_obj(svFiles[i]);
      for (ssChan in svChannel) {
         if (objn.has_key(ssChan)) {
            if (len(obj1[ssChan]) == len(objn[ssChan])) {
               obj1[ssChan] = obj1[ssChan] + objn[ssChan];
               obj1.channel_info[ssChan].nNC = obj1.channel_info[ssChan].nNC + 1;
            } else {
               log_error("", "NC_CalculateMean", "Channel %s in file %s has different number of points", ssChan, svFiles[i]);
            }
         } else {
            log_error("", "NC_CalculateMean", "Channel %s in file %s not found", ssChan, svFiles[i]);
         }
      }
      obj1.globals[sprintf("File%d", i)] = svFiles[i];
   }
   for (ssChan in svChannel) {
      obj1.channel_info[ssChan].nNC = obj1.channel_info[ssChan].nNC + 1;
      n = obj1.channel_info[ssChan].nNC;
      if (n > 0) {
         obj1[ssChan] = obj1[ssChan] / n;
      }
   }

   svPath = SplitPath(svFiles[1]);
   ssNewFile =  sum(svPath[1:3]) + "_Mean.nc2"
   bRet = nc_from_obj(obj1, ssNewFile);
   log_info("", ssNewFile, "NC-Mean Result. Double Click to open");
   return;
}

History

Version	Description
R2013.6	Description of parameter ncid.
5.14.7	New.

See also

Overview UniPlot Data Files, nc_from_obj, NC_Edit, NC_GetVarNames

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