Hi Christopher:
You are right that writing data a record at a time is the key to efficiently
writing files with an unlimited dimension. Note that in this case you need:
Dimension timeDim = outNc.addUnlimitedDimension(this.TIME);
Ive just added an example at:
http://www.unidata.ucar.edu/software/netcdf-java/tutorial/NetcdfWriteable.html#RecordAtaTime
Let me know if that helps, and if you have more questions.
John
Christopher Mueller wrote:
Hi all,
I’ve successfully created an empty NetcdfFile but I’m having some
difficulty writing data to the file. Just for a bit of context, I’m
trying to write data from a list of particles – each of which has an id,
lat, lon and concentration – to the nc file one timestep at a time.
In other words, I have a loop where a new list of particles is generated
each cycle. After they are generated, they need to be written to the nc
file as a “new” timestep.
Basically, I’d like to have a method that accepts the list of particles
(which contain lat, lon, conc) and a time and simply write a new time
record with all of the particles in the list. Is that possible??
I’m completely lost as to how I can do this efficiently. All of the
examples I can find show writing all of the variables for all times at
once – which doesn’t help (too much data to hold in memory until the end).
Any help is very much appreciated.
Thanks,
Chris
Here’s my file creation code just in case there’s something wrong here...:
outNc = NetcdfFileWriteable.createNew(fileLoc, true);
//make the dimensions
Dimension timeDim = outNc.addDimension(this.TIME, timeSteps);
Dimension partDim = outNc.addDimension(this.PARTICLE, numParts);
ArrayList dims = new ArrayList();
//add coordinate variables
outNc.addVariable(this.TIME, DataType.INT, new
Dimension[]{timeDim});
outNc.addVariable(this.PARTICLE, DataType.INT, new
Dimension[]{partDim});
dims.add(timeDim);
dims.add(partDim);
//add the variables
outNc.addVariable(this.LAT, DataType.DOUBLE, dims);
outNc.addVariable(this.LON, DataType.DOUBLE, dims);
outNc.addVariable(this.CCONC, DataType.DOUBLE, dims);
//add attributes to the variables
outNc.addVariableAttribute(this.LAT, "units", "deg North");
outNc.addVariableAttribute(this.LON, "units", "deg East");
outNc.addVariableAttribute(this.CCONC, "units", "moles liter^-1");
try {
outNc.create();
} catch (IOException ex) {
ex.printStackTrace();
}
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