Hi all,
I've n files containing Wave's height data. Each file contain wave data
at a specific time. I would to join the files to obtain a single file
with a forecast in a range of dates.
So for example,
file_1 contains wave height forecast for 19/03/2013 at 00:00
file_2 contains wave height forecast for 19/03/2013 at 06:00
file_3 contains wave height forecast for 19/03/2013 at 12:00
...
file_n-1 contains wave height forecast for 21/03/2013 at 00:00
file_n contains wave height forecast for 21/03/2013 at 06:00
I want to obtain a single file with wave height forecast in the range
19/03/2013 at 00:00 - 21/03/2013 at 06:00
I searched in the old posts and on google and I found this Class Utility:
public class AggregationUtil {
public static NetcdfDataset joinExisting(String aggDimName,
List<NetcdfFile> ncFiles) throws IOException {
NetcdfDataset aggDataset = new NetcdfDataset();
AggregationExistingOpenDataset joinExisting = new
AggregationExistingOpenDataset(aggDataset, aggDimName);
for (NetcdfFile ncFile : ncFiles) {
joinExisting.addOpenNcFile(ncFile);
}
joinExisting.finish(null);
aggDataset.setAggregation(joinExisting); // Makes sure that
ncFiles get closed when aggDataset gets closed.
aggDataset.finish();
// No enhancement done here!
return aggDataset;
}
public static class AggregationExistingOpenDataset extends
AggregationExisting {
public AggregationExistingOpenDataset(NetcdfDataset
joinExistingDataset, String aggDimName) {
super(joinExistingDataset, aggDimName, null);
}
public void addOpenNcFile(NetcdfFile openNcFile) {
addDataset(new ExistingOpenDataset(openNcFile));
}
@Override protected void closeDatasets() throws IOException {
for (Dataset dataset : getDatasets()) {
ExistingOpenDataset eod = (ExistingOpenDataset) dataset;
eod.openNcFile.close();
}
}
// The class being extended is *package private*. That's the
reason that AggregationUtil must be in
// ucar.nc2.ncml in the first place.
public class ExistingOpenDataset extends
AggregationOuterDimension.DatasetOuterDimension {
private NetcdfFile openNcFile;
public ExistingOpenDataset(NetcdfFile openNcFile) {
super(new MFileOS(new File(openNcFile.getLocation())));
//super(openNcFile.getLocation());
this.cacheLocation = openNcFile.getLocation(); //
Silences a warning in Aggregation.makeDataset().
this.openNcFile = openNcFile;
}
@Override public NetcdfFile acquireFile(CancelTask
cancelTask) throws IOException {
return openNcFile;
}
@Override protected void close(NetcdfFile ncfile) throws
IOException {
// DON'T ACTUALLY CLOSE ncfile HERE!
// We're going to let it stay open until the user
invokes Aggregation.close() (which, in turn, calls
// AggregationExistingOpenDataset.closeDatasets()).
}
}
}
}
and to test I tryed this:
public class Test {
static public void main(String args[]) {
// Test Merge
try {
joinExisting();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void joinExisting() throws IOException,
InvalidRangeException {
File janFile = new
File("C:/Users/Test/Desktop/union/US058GOCN-GR1mdl.0110_0240_00000F0RL2013031800_0001_000000-000000sig_wav_ht");
File febFile = new
File("C:/Users/Test/Desktop/union/US058GOCN-GR1mdl.0110_0240_09000F0RL2013031800_0001_000000-000000sig_wav_ht");
NetcdfFile janNcFile = NetcdfFile.open(janFile.getAbsolutePath());
NetcdfFile febNcFile = NetcdfFile.open(febFile.getAbsolutePath());
NetcdfDataset joinExistingDataset =
AggregationUtil.joinExisting("time", Arrays.asList(janNcFile, febNcFile));
try {
System.out.println(joinExistingDataset);
System.out.println("Time levels:" +
joinExistingDataset.readSection("time"));
GridDataset gds = new GridDataset(joinExistingDataset);
NetcdfCFWriter writer = new NetcdfCFWriter();
List<String> wantedVars = new ArrayList<String>();
for (VariableSimpleIF var : gds.getDataVariables()) {
System.out.println("Variabile:" + var.getFullName());
wantedVars.add(var.getFullName());
}
try {
System.out.println("gds=" + gds);
writer.makeFile("C:/Users/Crisma/Desktop/union/out", gds, wantedVars,
gds.getBoundingBox(), 1, null, null, 1, false,
NetcdfFileWriter.Version.netcdf3 );
} catch (Exception e) {
e.printStackTrace();
}
} finally {
joinExistingDataset.close(); // Closes janFile and febFile.
}
}
}
If I run this I obtain:
netcdf null {
dimensions:
lon = 360;
lat = 181;
time = 2;
variables:
float lat(lat=181);
:units = "degrees_north";
float lon(lon=360);
:units = "degrees_east";
int time(time=2);
:units = "Hour since 2013-03-18T00:00:00Z";
:standard_name = "time";
:long_name = "Uninitialized analysis / image product / forecast
product valid for RT + P1";
float sig_wav_ht_surface(time=2, lat=181, lon=360);
:long_name = "ocean wave forecasting A fictitious wave with a
height and period equal to the average height of the highest third of
the actual waves that pass a fixed point @ Ground or water surface";
:units = "m";
:missing_value = NaNf; // float
:grid_mapping = "LatLon_Projection";
:Grib_Variable_Id = "VAR_58-0-3-100_L1";
:Grib1_Center = 58; // int
:Grib1_Subcenter = 0; // int
:Grib1_TableVersion = 3; // int
:Grib1_Parameter = 100; // int
:Grib1_Parameter_Name = "sig_wav_ht";
:Grib1_Level_Type = 1; // int
:Originating_or_generating_Center = "Fleet Numerical Meteorology and
Oceanography Center, Monterey, CA, USA";
:Originating_or_generating_Subcenter = "0";
:Generating_process_or_model = "Wave Watch 3rd Revision Global";
:Conventions = "CF-1.6";
:history = "Read using CDM IOSP Grib1Collection";
:featureType = "GRID";
:file_format = "GRIB-1";
}
Time levels:0 90
Variabile:sig_wav_ht_surface
gds=ucar.nc2.dt.grid.GridDataset@177f409c
java.io.IOException: spi is null, perhaps file has been closed. Trying
to read variable sig_wav_ht_surface
at ucar.nc2.NetcdfFile.readData(NetcdfFile.java:1939)
at ucar.nc2.Variable.reallyRead(Variable.java:859)
at ucar.nc2.Variable._read(Variable.java:831)
at ucar.nc2.Variable.read(Variable.java:709)
at ucar.nc2.ncml.Aggregation$Dataset.read(Aggregation.java:683)
at
ucar.nc2.ncml.AggregationOuterDimension.reallyRead(AggregationOuterDimension.java:374)
at ucar.nc2.dataset.VariableDS._read(VariableDS.java:502)
at ucar.nc2.Variable.read(Variable.java:709)
at ucar.nc2.FileWriter.copyAll(FileWriter.java:325)
at ucar.nc2.FileWriter.copyVarData(FileWriter.java:286)
at ucar.nc2.FileWriter.writeToFile(FileWriter.java:241)
at ucar.nc2.FileWriter.writeToFile(FileWriter.java:103)
at Test.joinExisting(Test.java:115)
at Test.main(Test.java:57)
Looking to the output seems that the join was ok (I've 2 time levels)
but when i try to write the result in a file I obtain an exception.
Does Have someone some suggestions?
Best regards
Giovanni
