ucar.nc2.dataset.conv.COARDSConvention Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of org.gecko.ucar.netcdf Show documentation
Re-packaged Unidata netCDF
The newest version!
/*
 * Copyright (c) 1998-2018 John Caron and University Corporation for Atmospheric Research/Unidata
 * See LICENSE for license information.
 */
package ucar.nc2.dataset.conv;

import ucar.nc2.Attribute;
import ucar.nc2.constants.CF;
import ucar.nc2.dataset.*;
import ucar.nc2.time.Calendar;
import ucar.nc2.units.SimpleUnit;
import ucar.nc2.Variable;
import ucar.nc2.constants.AxisType;
import ucar.nc2.util.CancelTask;
import java.io.IOException;
import java.util.List;

/**
 * COARDS Convention.
 * see http://ferret.wrc.noaa.gov/noaa_coop/coop_cdf_profile.html
 *
 * @author caron
 */

public class COARDSConvention extends CoordSysBuilder {

  /*
   * The COARDS standard offers limited support for climatological time. For compatibility with COARDS, time coordinates
   * should also be
   * recognised as climatological if they have a units attribute of time-units relative to midnight on 1 January in year
   * 0
   * i.e. since 0-1-1 in udunits syntax , and provided they refer to the real-world calendar. We do not recommend this
   * convention because
   * (a) it does not provide any information about the intervals used to compute the climatology, and
   * (b) there is no standard for how dates since year 1 will be encoded with units having a reference time in year 0,
   * since this year does not exist; consequently there may be inconsistencies among software packages in the
   * interpretation of the
   * time coordinates. Year 0 may be a valid year in non-real-world calendars, and therefore cannot be used to signal
   * climatological
   * time in such cases.
   */

  public static boolean isMine(String hasName) {
    if (hasName.equalsIgnoreCase("COARDS"))
      return true;
    List names = breakupConventionNames(hasName);
    for (String name : names) {
      if (name.equalsIgnoreCase("COARDS"))
        return true;
    }
    return false;
  }


  public COARDSConvention() {
    this.conventionName = "COARDS";
  }

  protected boolean checkTimeVarForCalendar(Variable var) {
    boolean hasChanged = false;
    String unit = var.getUnitsString();
    if (unit != null) {
      unit = unit.trim();
      if (SimpleUnit.isDateUnit(unit)) {
        Attribute calAttr = var.attributes().findAttributeIgnoreCase(CF.CALENDAR);
        if (calAttr == null) {
          calAttr = new Attribute(CF.CALENDAR, Calendar.gregorian.toString());
          var.addAttribute(calAttr);
          hasChanged = true;
        }
      }
    }
    return hasChanged;
  }

  @Override
  public void augmentDataset(NetcdfDataset ds, CancelTask cancelTask) throws IOException {
    boolean hasChanged = false;
    boolean hasChangedThisTime;
    for (Variable var : ds.getVariables()) {
      hasChangedThisTime = checkTimeVarForCalendar(var);
      if (hasChangedThisTime) {
        hasChanged = true;
      }
    }
    if (hasChanged) {
      ds.finish();
    }
  }

  protected boolean checkForMeter = true;

  // we assume that coordinate axes get identified by being coordinate variables
  protected AxisType getAxisType(NetcdfDataset ncDataset, VariableEnhanced v) {

    String unit = v.getUnitsString();
    if (unit == null)
      return null;
    unit = unit.trim();

    if (unit.equalsIgnoreCase("degrees_east") || unit.equalsIgnoreCase("degrees_E") || unit.equalsIgnoreCase("degreesE")
        || unit.equalsIgnoreCase("degree_east") || unit.equalsIgnoreCase("degree_E")
        || unit.equalsIgnoreCase("degreeE"))
      return AxisType.Lon;

    if (unit.equalsIgnoreCase("degrees_north") || unit.equalsIgnoreCase("degrees_N")
        || unit.equalsIgnoreCase("degreesN") || unit.equalsIgnoreCase("degree_north")
        || unit.equalsIgnoreCase("degree_N") || unit.equalsIgnoreCase("degreeN"))
      return AxisType.Lat;

    if (SimpleUnit.isDateUnit(unit)) {
      return AxisType.Time;
    }
    // look for other z coordinate
    if (SimpleUnit.isCompatible("mbar", unit))
      return AxisType.Pressure;
    if (unit.equalsIgnoreCase("level") || unit.equalsIgnoreCase("layer") || unit.equalsIgnoreCase("sigma_level"))
      return AxisType.GeoZ;

    String positive = ncDataset.findAttValueIgnoreCase((Variable) v, CF.POSITIVE, null);
    if (positive != null) {
      if (SimpleUnit.isCompatible("m", unit))
        return AxisType.Height;
      else
        return AxisType.GeoZ;
    }

    // a bad idea, but CDC SST relies on it :
    // :Source = "NOAA/National Climatic Data Center";
    // :Contact = "Dick Reynolds, email: [email protected] & Chunying Liu, email: [email protected]";
    // :netcdf_Convention = "COARDS";
    // if (checkForMeter && SimpleUnit.isCompatible("m", unit))
    // return AxisType.Height;

    return null;
  }

}