Java Code Examples for ucar.nc2.Variable#setDimensions()

public void open(RandomAccessFile raf, NetcdfFile ncfile, CancelTask cancelTask) throws IOException {
  super.open(raf, ncfile, cancelTask);

  readHDR();

  ncfile.addDimension(null, new Dimension("lat", nlats));
  ncfile.addDimension(null, new Dimension("lon", nlons));

  Variable elev = new Variable(ncfile, null, null, "elevation");
  elev.setDataType(DataType.SHORT);
  elev.setDimensions("lat lon");

  elev.addAttribute(new Attribute(CDM.UNITS, "m"));
  elev.addAttribute(new Attribute("units_desc", "meters above sea level"));
  elev.addAttribute(new Attribute(CDM.LONG_NAME, "digital elevation in meters above mean sea level"));
  elev.addAttribute(new Attribute(CDM.MISSING_VALUE, (short) -9999));
  ncfile.addVariable(null, elev);

  Variable lat = new Variable(ncfile, null, null, "lat");
  lat.setDataType(DataType.FLOAT);
  lat.setDimensions("lat");
  lat.addAttribute(new Attribute(CDM.UNITS, CDM.LAT_UNITS));
  ncfile.addVariable(null, lat);
  Array data = Array.makeArray(DataType.FLOAT, nlats, starty, -incr);
  lat.setCachedData(data, false);

  Variable lon = new Variable(ncfile, null, null, "lon");
  lon.setDataType(DataType.FLOAT);
  lon.setDimensions("lon");
  lon.addAttribute(new Attribute(CDM.UNITS, CDM.LON_UNITS));
  ncfile.addVariable(null, lon);
  Array lonData = Array.makeArray(DataType.FLOAT, nlons, startx, incr);
  lon.setCachedData(lonData, false);

  ncfile.addAttribute(null, new Attribute(CDM.CONVENTIONS, "CF-1.0"));
  ncfile.addAttribute(null, new Attribute("History", "Direct read by Netcdf-Java CDM library"));
  ncfile.addAttribute(null, new Attribute("Source", "http://eros.usgs.gov/products/elevation/gtopo30.html"));

  ncfile.finish();
}
 

private void addLatLon2D(NetcdfFile ncfile, List<Variable> varList, Projection proj, CoordinateAxis xaxis,
    CoordinateAxis yaxis) throws IOException {

  double[] xData = (double[]) xaxis.read().get1DJavaArray(double.class);
  double[] yData = (double[]) yaxis.read().get1DJavaArray(double.class);

  List<Dimension> dims = new ArrayList<Dimension>();
  dims.add(yaxis.getDimension(0));
  dims.add(xaxis.getDimension(0));

  Variable latVar = new Variable(ncfile, null, null, "lat");
  latVar.setDataType(DataType.DOUBLE);
  latVar.setDimensions(dims);
  latVar.addAttribute(new Attribute(CDM.UNITS, CDM.LAT_UNITS));
  latVar.addAttribute(new Attribute(CDM.LONG_NAME, "latitude coordinate"));
  latVar.addAttribute(new Attribute(CF.STANDARD_NAME, "latitude"));
  latVar.addAttribute(new Attribute(_Coordinate.AxisType, AxisType.Lat.toString()));

  Variable lonVar = new Variable(ncfile, null, null, "lon");
  lonVar.setDataType(DataType.DOUBLE);
  lonVar.setDimensions(dims);
  lonVar.addAttribute(new Attribute(CDM.UNITS, CDM.LON_UNITS));
  lonVar.addAttribute(new Attribute(CDM.LONG_NAME, "longitude coordinate"));
  lonVar.addAttribute(new Attribute(CF.STANDARD_NAME, "longitude"));
  lonVar.addAttribute(new Attribute(_Coordinate.AxisType, AxisType.Lon.toString()));

  int nx = xData.length;
  int ny = yData.length;

  // create the data
  ProjectionPointImpl projPoint = new ProjectionPointImpl();
  LatLonPointImpl latlonPoint = new LatLonPointImpl();
  double[] latData = new double[nx * ny];
  double[] lonData = new double[nx * ny];
  for (int i = 0; i < ny; i++) {
    for (int j = 0; j < nx; j++) {
      projPoint.setLocation(xData[j], yData[i]);
      proj.projToLatLon(projPoint, latlonPoint);
      latData[i * nx + j] = latlonPoint.getLatitude();
      lonData[i * nx + j] = latlonPoint.getLongitude();
    }
  }
  Array latDataArray = Array.factory(DataType.DOUBLE, new int[] {ny, nx}, latData);
  latVar.setCachedData(latDataArray, false);

  Array lonDataArray = Array.factory(DataType.DOUBLE, new int[] {ny, nx}, lonData);
  lonVar.setCachedData(lonDataArray, false);

  varList.add(latVar);
  varList.add(lonVar);
}
 

private void createTimeCoordinate(NetcdfDataset ds, Variable ncVar) {
  // Time coordinate is stored in the attribute validTimes
  // One caveat is that the times have two bounds an upper and a lower

  // get the times values
  Attribute timesAtt = ncVar.findAttribute("validTimes");
  if (timesAtt == null)
    return;
  Array timesArray = timesAtt.getValues();

  // get every other one LOOK this is awkward
  try {
    int n = (int) timesArray.getSize();
    List<Range> list = new ArrayList<>();
    list.add(new Range(0, n - 1, 2));
    timesArray = timesArray.section(list);
  } catch (InvalidRangeException e) {
    throw new IllegalStateException(e);
  }

  // make sure it matches the dimension
  DataType dtype = DataType.getType(timesArray);
  int nTimesAtt = (int) timesArray.getSize();

  // create a special dimension and coordinate variable
  Dimension dimTime = ncVar.getDimension(0);
  int nTimesDim = dimTime.getLength();
  if (nTimesDim != nTimesAtt) {
    parseInfo.format(" **error ntimes in attribute (%d) doesnt match dimension length (%d) for variable %s%n",
        nTimesAtt, nTimesDim, ncVar.getFullName());
    return;
  }

  // add the dimension
  String dimName = ncVar.getFullName() + "_timeCoord";
  Dimension newDim = new Dimension(dimName, nTimesDim);
  ds.addDimension(null, newDim);

  // add the coordinate variable
  String units = "seconds since 1970-1-1 00:00:00";
  String desc = "time coordinate for " + ncVar.getFullName();

  CoordinateAxis1D timeCoord = new CoordinateAxis1D(ds, null, dimName, dtype, dimName, units, desc);
  timeCoord.setCachedData(timesArray, true);
  timeCoord.addAttribute(new Attribute(_Coordinate.AxisType, AxisType.Time.toString()));
  ds.addCoordinateAxis(timeCoord);

  parseInfo.format(" added coordinate variable %s%n", dimName);

  // now make the original variable use the new dimension
  List<Dimension> dimsList = new ArrayList(ncVar.getDimensions());
  dimsList.set(0, newDim);
  ncVar.setDimensions(dimsList);

  // better to explicitly set the coordinate system
  ncVar.addAttribute(new Attribute(_Coordinate.Axes, dimName + " yCoord xCoord"));

  // fix the attributes
  Attribute att = ncVar.findAttribute("fillValue");
  if (att != null)
    ncVar.addAttribute(new Attribute(CDM.FILL_VALUE, att.getNumericValue()));
  att = ncVar.findAttribute("descriptiveName");
  if (null != att)
    ncVar.addAttribute(new Attribute(CDM.LONG_NAME, att.getStringValue()));

  // ncVar.enhance();
}