ucar.nc2.iosp.misc.Nldn Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of cdm Show documentation
Show all versions of cdm Show documentation
The NetCDF-Java Library is a Java interface to NetCDF files,
as well as to many other types of scientific data formats.
The newest version!
/*
* Copyright 1998-2009 University Corporation for Atmospheric Research/Unidata
*
* Portions of this software were developed by the Unidata Program at the
* University Corporation for Atmospheric Research.
*
* Access and use of this software shall impose the following obligations
* and understandings on the user. The user is granted the right, without
* any fee or cost, to use, copy, modify, alter, enhance and distribute
* this software, and any derivative works thereof, and its supporting
* documentation for any purpose whatsoever, provided that this entire
* notice appears in all copies of the software, derivative works and
* supporting documentation. Further, UCAR requests that the user credit
* UCAR/Unidata in any publications that result from the use of this
* software or in any product that includes this software. The names UCAR
* and/or Unidata, however, may not be used in any advertising or publicity
* to endorse or promote any products or commercial entity unless specific
* written permission is obtained from UCAR/Unidata. The user also
* understands that UCAR/Unidata is not obligated to provide the user with
* any support, consulting, training or assistance of any kind with regard
* to the use, operation and performance of this software nor to provide
* the user with any updates, revisions, new versions or "bug fixes."
*
* THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package ucar.nc2.iosp.misc;
import ucar.ma2.*;
import ucar.nc2.*;
import ucar.nc2.constants.AxisType;
import ucar.nc2.constants.CDM;
import ucar.nc2.constants.CF;
import ucar.nc2.util.CancelTask;
import ucar.unidata.io.RandomAccessFile;
import java.io.IOException;
import java.nio.ByteBuffer;
/**
* National Lightning Detection Network (NLDN)
*
* @author caron
* @see "http://www.unidata.ucar.edu/data/lightning.html"
* @since Nov 19, 2008
*/
public class Nldn extends AbstractLightningIOSP {
/*
Field Example
-------------------+---------------------
date/time (msec) 09/22/93 10:22:33.334
latitude 47.33
longitude -87.116
polarity/signal strength -188.7
multiplicity 6
ellipse angle 174
semi-major axis 6.0
eccentricity 2.0
chi-square 1.0
The specifics for the binary NLDN data record contained in the IDD is:
Size Name Description
--------+---------+----------------------------------------------------
char[4] NLDN 'NLDN' marks the start of record
int[4] tsec time in seconds since 1970
int[4] nsec nanoseconds since tsec (seems to be thousandths)
int[4] lat latitude [deg] * 1000
int[4] lon longitude [deg] * 1000
short[2] fill padding
short[2] sgnl signal strength * 10 [150 NLDN measures ~= 30 kAmps]
short[2] fill padding
short[2] mult multiplicity [#strokes per flash]
char[1] fill padding
char[1] semimaj semi-major axis
char[1] eccent eccentricity
char[1] angle ellipse angle
char[1] chisqr chi-square
*/
/**
* The magic mushroom
*/
private static final String MAGIC = "NLDN";
/**
* The data structure
*/
private Structure seq;
/**
* The structure members
*/
private StructureMembers sm;
/**
* The time in seconds variable name
*/
private static final String TSEC = "tsec";
/**
* The time in nanoseconds from TSEC variable name
*/
private static final String NSEC = "nsec";
/**
* The chi squared variable name
*/
private static final String CHISQR = "chisqr";
/**
* The fill variable name
*/
private static final String FILL = "fill";
/**
* header size
*/
private static final int recHeader = 84;
/**
* record size
*/
private static final int recSize = 28;
/**
* Check if this is a valid file for this IOServiceProvider.
* You must make this method thread safe, ie dont keep any state.
*
* @param raf RandomAccessFile
* @return true if valid.
* @throws IOException if read error
*/
public boolean isValidFile(RandomAccessFile raf) throws IOException {
raf.seek(0);
String test = raf.readString(MAGIC.length());
return test.equals(MAGIC);
}
/**
* Get a unique id for this file type.
*
* @return registered id of the file type
* @see "http://www.unidata.ucar.edu/software/netcdf-java/formats/FileTypes.html"
*/
public String getFileTypeId() {
return "NLDN";
}
/**
* Get a human-readable description for this file type.
*
* @return description of the file type
* @see "http://www.unidata.ucar.edu/software/netcdf-java/formats/FileTypes.html"
*/
public String getFileTypeDescription() {
return "National Lightning Detection Network";
}
/**
* Open existing file, and populate ncfile with it. This method is only
* called by the NetcdfFile constructor on itself. The provided NetcdfFile
* object will be empty except for the location String and the
* IOServiceProvider associated with this NetcdfFile object.
*
* @param raf the file to work on, it has already passed the
* isValidFile() test.
* @param ncfile add objects to this empty NetcdfFile
* @param cancelTask used to monitor user cancellation; may be null.
* @throws IOException if read error
*/
public void open(RandomAccessFile raf, NetcdfFile ncfile, CancelTask cancelTask) throws IOException {
super.open(raf, ncfile, cancelTask);
seq = new Sequence(ncfile, null, null, RECORD);
ncfile.addVariable(null, seq);
/*
makeLightningVariable(NetcdfFile ncfile, Group group,
Structure seq, String name,
DataType dataType, String dims,
String longName, String cfName,
String units, AxisType type) {
*/
Variable v = makeLightningVariable(ncfile, null, seq, TSEC, DataType.INT,
"", "time of stroke", null,
secondsSince1970,
AxisType.Time);
seq.addMemberVariable(v);
v = makeLightningVariable(ncfile, null, seq, "nsec", DataType.INT,
"", "nanoseconds since tsec", null,
"1.0e-9 s", null);
seq.addMemberVariable(v);
v = makeLightningVariable(ncfile, null, seq, LAT, DataType.INT, "",
"latitude", "latitude", CDM.LAT_UNITS,
AxisType.Lat);
v.addAttribute(new Attribute(CDM.SCALE_FACTOR, new Float(1.0e-3)));
seq.addMemberVariable(v);
v = makeLightningVariable(ncfile, null, seq, LON, DataType.INT, "",
"longitude", "longitude", CDM.LON_UNITS,
AxisType.Lon);
v.addAttribute(new Attribute(CDM.SCALE_FACTOR, new Float(1.0e-3)));
seq.addMemberVariable(v);
v = makeLightningVariable(
ncfile, null, seq, SIGNAL, DataType.SHORT, "",
"signal strength/polarity [150 NLDN measures ~= 30 kAmps]", null, "",
null);
v.addAttribute(new Attribute(CDM.SCALE_FACTOR, new Float(1.0e-1)));
seq.addMemberVariable(v);
v = makeLightningVariable(ncfile, null, seq, MULTIPLICITY,
DataType.BYTE, "",
"multiplicity [#strokes per flash]", null,
"", null);
seq.addMemberVariable(v);
v = new Variable(ncfile, null, seq, FILL);
v.setDataType(DataType.BYTE);
v.setDimensions("");
seq.addMemberVariable(v);
v = makeLightningVariable(ncfile, null, seq, MAJOR_AXIS,
DataType.BYTE, "",
"error ellipse semi-major axis", null, "",
null);
seq.addMemberVariable(v);
v = makeLightningVariable(ncfile, null, seq, ECCENTRICITY,
DataType.BYTE, "",
"error ellipse eccentricity ", null, "",
null);
seq.addMemberVariable(v);
v = makeLightningVariable(ncfile, null, seq, ELLIPSE_ANGLE,
DataType.BYTE, "",
"error ellipse axis angle of orientation ",
null, "degrees", null);
seq.addMemberVariable(v);
v = makeLightningVariable(ncfile, null, seq, CHISQR, DataType.BYTE,
"", "chi-squared", null, "", null);
seq.addMemberVariable(v);
addLightningGlobalAttributes(ncfile);
ncfile.finish();
sm = seq.makeStructureMembers();
sm.findMember(TSEC).setDataParam(0);
sm.findMember(NSEC).setDataParam(4);
sm.findMember(LAT).setDataParam(8);
sm.findMember(LON).setDataParam(12);
sm.findMember(SIGNAL).setDataParam(18);
sm.findMember(MULTIPLICITY).setDataParam(22);
sm.findMember(FILL).setDataParam(23);
sm.findMember(MAJOR_AXIS).setDataParam(24);
sm.findMember(ECCENTRICITY).setDataParam(25);
sm.findMember(ELLIPSE_ANGLE).setDataParam(26);
sm.findMember(CHISQR).setDataParam(27);
sm.setStructureSize(recSize);
}
/**
* Add the global attributes.
*
* @param ncfile the file to add to
*/
protected void addLightningGlobalAttributes(NetcdfFile ncfile) {
super.addLightningGlobalAttributes(ncfile);
ncfile.addAttribute(null,
new Attribute("title", "NLDN Lightning Data"));
ncfile.addAttribute(null, new Attribute(CDM.CONVENTIONS, "NLDN-CDM"));
}
/* The specifics for the binary NLDN data record contained in the IDD is:
Size Name Description
--------+---------+----------------------------------------------------
char[4] NLDN 'NLDN' marks the start of record
int[4] tsec time in seconds since 1970
int[4] nsec nanoseconds since tsec (seems to be thousandths)
int[4] lat latitude [deg] * 1000
int[4] lon longitude [deg] * 1000
short[2] fill padding
short[2] sgnl signal strength * 10 [150 NLDN measures ~= 30 kAmps]
short[2] fill padding
short[2] mult multiplicity [#strokes per flash]
char[1] fill padding
char[1] semimaj semi-major axis
char[1] eccent eccentricity
char[1] angle ellipse angle
char[1] chisqr chi-square
*/
/* public Array readData(Variable v2, Section section) throws IOException, InvalidRangeException {
Range r = section.getRange(0);
int nrecs = r.length();
byte[] bb = new byte[nrecs * recSize];
int pos = 0;
Range.Iterator iter = r.getIterator();
while (iter.hasNext()) {
int index = iter.next();
raf.seek(recHeader + index * recSize);
raf.read(bb, pos, recSize);
pos += recSize;
}
return new ArrayStructureBB(sm, new int[]{nrecs}, ByteBuffer.wrap(bb), 0);
} */
/**
* Read data from a top level Variable and return a memory resident Array.
* This Array has the same element type as the Variable, and the requested shape.
*
* @param v2 a top-level Variable
* @param section the section of data to read.
* There must be a Range for each Dimension in the variable, in order.
* Note: no nulls allowed. IOSP may not modify.
* @return the requested data in a memory-resident Array
* @throws IOException if read error
* @throws InvalidRangeException if invalid section
* @see ucar.ma2.Range
*/
public Array readData(Variable v2, Section section)
throws IOException, InvalidRangeException {
return new ArraySequence(sm, new SeqIter(), nelems);
}
private int nelems = -1;
/**
* Get the structure iterator
*
* @param s the Structure
* @param bufferSize the buffersize
* @return the data iterator
* @throws java.io.IOException if problem reading data
*/
public StructureDataIterator getStructureIterator(Structure s,
int bufferSize)
throws java.io.IOException {
return new SeqIter();
}
/**
* Sequence Iterator
*
* @author Unidata Development Team
*/
private class SeqIter implements StructureDataIterator {
/**
* done?
*/
private int done = 0;
/**
* number bytes already read
*/
private int alreadyRead = 0;
/**
* next index
*/
private int nextIndex = 0;
/**
* the wrapped asbb
*/
private ArrayStructureBB asbb = null;
/**
* total bytes
*/
private long totalBytes;
/**
* bytes read
*/
private long bytesRead;
/**
* Create a new one
*
* @throws IOException problem reading the file
*/
SeqIter() throws IOException {
totalBytes = (int) raf.length();
raf.seek(0);
}
@Override
public StructureDataIterator reset() {
done = 0;
alreadyRead = 0;
bytesRead = 0;
nextIndex = 0;
try {
raf.seek(0);
} catch (IOException e) {
throw new RuntimeException(e);
}
return this;
}
@Override
public boolean hasNext() throws IOException {
if (done < alreadyRead) {
return true;
}
return readHeader();
}
@Override
public StructureData next() throws IOException {
done++;
return asbb.getStructureData(nextIndex++);
}
/**
* Read the header
*
* @return true if okay
* @throws IOException problem reading file
*/
private boolean readHeader() throws IOException {
if ((bytesRead + recHeader) > totalBytes) {
nelems = done; // record the number of elements for next time
return false;
}
byte[] b = new byte[recHeader];
raf.readFully(b);
bytesRead += recHeader;
ByteBuffer bb = ByteBuffer.wrap(b);
int count = bb.getInt(8);
if (count == 0) {
return readHeader();
}
if ((bytesRead + count * recSize) > totalBytes) {
return false;
}
byte[] data = new byte[count * recSize];
raf.readFully(data);
bytesRead += count * recSize;
alreadyRead += count;
nextIndex = 0;
ByteBuffer bbdata = ByteBuffer.wrap(data);
asbb = new ArrayStructureBB(sm, new int[]{count}, bbdata, 0);
return true;
}
@Override
public void setBufferSize(int bytes) {
}
@Override
public int getCurrentRecno() {
return done - 1;
}
@Override
public void finish() {
// ignored
}
}
// this is thye start of a buffererd iterator
/* private class MySDIter implements StructureDataIterator {
private int done = 0;
private int readStart = 0;
private int recsAlreadyRead = 0;
private int readAtaTime;
private ArrayStructureBB asbb = null;
private int recsLeft;
private int recsDone;
MySDIter(int bufferSize) throws IOException {
setBufferSize( bufferSize);
recsLeft = (int) raf.length() / recSize;
recsDone = 0;
}
public boolean hasNext() {
if (done < recsAlreadyRead) return true;
return (recsLeft > 0);
}
public StructureDataIterator reset() {
done = 0;
readStart = 0;
readRead = 0;
return this;
}
public StructureData next() throws IOException {
if (done >= readStart) {
readNextBuffer();
}
done++;
return asbb.getStructureData( readRead++);
}
private void readNextBuffer() throws IOException {
bytesLeft = (int)(raf.length() - raf.getFilePointer());
int recsLeft = bytesLeft / recSize;
int recsToRead = Math.min(recsLeft, readAtaTime);
byte[] bb = new byte[recsToRead * recSize];
ByteBuffer.wrap(bb);
asbb = new ArrayStructureBB(sm, new int[]{nrecs}, bb, 0);
recsAlreadyRead += recsToRead;
readRead = 0;
}
public void setBufferSize(int bytes) {
if (done > 0) return; // too late
if (bytes <= 0)
bytes = defaultBufferSize;
readAtaTime = Math.max( 10, bytes / recSize);
}
} */
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy