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*
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// $Id: SimpleTrajectoryObsDataset.java 63 2006-07-12 21:50:51Z edavis $
package ucar.nc2.dt.trajectory;
import ucar.nc2.Dimension;
import ucar.nc2.Variable;
import ucar.nc2.constants.FeatureType;
import ucar.nc2.dt.TypedDataset;
import ucar.nc2.dt.TypedDatasetFactoryIF;
import ucar.nc2.dataset.NetcdfDataset;
import ucar.nc2.units.DateUnit;
import ucar.nc2.units.SimpleUnit;
import java.io.IOException;
import java.util.Date;
import java.util.List;
/**
* Implements TrajectoryDataset for datasets with these characteristics:
* <ul>
* <li> it has only one dimension, the dimension is UNLIMITED and is named "time"</li>
* <li> it has one coordinate variable, time(time), with units that
* are udunits time units</li>
* <li> has the variables latitude(time), longitude(time), and altitude(time) with
* units "deg", "deg", and "m", respectively.
* </ul>
*
* @author edavis
* @since Feb 22, 2005T5:37:14 PM
*/
public class SimpleTrajectoryObsDataset extends SingleTrajectoryObsDataset implements TypedDatasetFactoryIF
{
private static String timeDimName = "time";
private static String timeVarName = "time";
private static String latVarName = "latitude";
private static String lonVarName = "longitude";
private static String elevVarName = "altitude";
private static String trajId = "trajectory data";
static public boolean isValidFile(NetcdfDataset ncd)
{
return ( buildConfig( ncd ) != null );
}
private static Config buildConfig( NetcdfDataset ncd )
{
// Check that only one dimension and that it is named "time".
List list = ncd.getRootGroup().getDimensions();
if ( list.size() != 1) return null;
Dimension d = (Dimension) list.get(0);
if ( ! d.getName().equals( timeDimName)) return null;
Config trajConfig = new Config();
trajConfig.setTimeDim( d);
// Check that have variable time(time) with units that are udunits time
Variable var = ncd.getRootGroup().findVariable( timeVarName);
if ( var == null) return null;
list = var.getDimensions();
if ( list.size() != 1) return null;
d = (Dimension) list.get(0);
if ( ! d.getName().equals( timeDimName)) return null;
String units = var.findAttribute( "units").getStringValue();
Date date = DateUnit.getStandardDate( "0 " + units);
if ( date == null) return null;
trajConfig.setTimeVar( var);
// Check for variable latitude(time) with units of "deg".
var = ncd.getRootGroup().findVariable( latVarName);
if ( var == null ) return null;
list = var.getDimensions();
if ( list.size() != 1) return null;
d = (Dimension) list.get(0);
if ( ! d.getName().equals( timeDimName)) return null;
units = var.findAttribute( "units").getStringValue();
if ( ! SimpleUnit.isCompatible( units, "degrees_north")) return null;
trajConfig.setLatVar( var);
// Check for variable longitude(time) with units of "deg".
var = ncd.getRootGroup().findVariable( lonVarName);
if ( var == null ) return null;
list = var.getDimensions();
if ( list.size() != 1) return null;
d = (Dimension) list.get(0);
if ( ! d.getName().equals( timeDimName)) return null;
units = var.findAttribute( "units").getStringValue();
if ( ! SimpleUnit.isCompatible( units, "degrees_east")) return null;
trajConfig.setLonVar( var);
// Check for variable altitude(time) with units of "m".
var = ncd.getRootGroup().findVariable( elevVarName);
if ( var == null) return null;
list = var.getDimensions();
if ( list.size() != 1) return null;
d = (Dimension) list.get(0);
if ( ! d.getName().equals( timeDimName)) return null;
units = var.findAttribute( "units").getStringValue();
if ( ! SimpleUnit.isCompatible( units, "meters")) return null;
trajConfig.setElevVar( var);
trajConfig.setTrajectoryId( trajId);
return trajConfig;
}
/////////////////////////////////////////////////
// TypedDatasetFactoryIF
public boolean isMine(NetcdfDataset ds) { return isValidFile(ds); }
public TypedDataset open( NetcdfDataset ncd, ucar.nc2.util.CancelTask task, StringBuilder errlog) throws IOException {
return new SimpleTrajectoryObsDataset( ncd);
}
public FeatureType getScientificDataType() { return FeatureType.TRAJECTORY; }
public SimpleTrajectoryObsDataset() {}
public SimpleTrajectoryObsDataset( NetcdfDataset ncd ) throws IOException
{
super( ncd);
Config trajConfig = buildConfig( ncd);
this.setTrajectoryInfo( trajConfig );
}
}