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NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
attacheed are a couple of examples that work
package ucar.nc2;
import junit.framework.*;
import ucar.ma2.*;
import java.io.IOException;
/**
* Simple example to create a new netCDF file corresponding to the following
* CDL:
* <pre>
* netcdf example {
* dimensions:
* lat = 3 ;
* lon = 4 ;
* time = UNLIMITED ;
* variables:
* int rh(time, lat, lon) ;
* rh:long_name="relative humidity" ;
* rh:units = "percent" ;
* double T(time, lat, lon) ;
* T:long_name="surface temperature" ;
* T:units = "degC" ;
* float lat(lat) ;
* lat:units = "degrees_north" ;
* float lon(lon) ;
* lon:units = "degrees_east" ;
* int time(time) ;
* time:units = "hours" ;
* // global attributes:
* :title = "Example Data" ;
* data:
* rh
* 1, 2, 3, 4,
* 5, 6, 7, 8,
* 9, 10, 11, 12,
* 21, 22, 23, 24,
* 25, 26, 27, 28,
* 29, 30, 31, 32 ;
* T
* 1, 2, 3, 4,
* 2, 4, 6, 8,
* 3, 6, 9, 12,
* 2.5, 5, 7.5, 10,
* 5, 10, 15, 20,
* 7.5, 15, 22.5, 30 ;
* lat = 41, 40, 39 ;
* lon = -109, -107, -105, -103 ;
* time = 6, 18 ;
* }
* </pre>
*
* @author : Russ Rew
* @author : John Caron
*/
public class TestWriteRecord extends TestCase {
static String fileName = TestNC2.topDir+"testWriteRecord.nc"; // default name
of file created
static boolean dumpAfterCreate = false;
public TestWriteRecord( String name) {
super(name);
}
public void testNC3WriteWithRecordVariables() throws IOException {
NetcdfFileWriteable ncfile = new NetcdfFileWriteable(fileName, false);
// define dimensions, including unlimited
Dimension latDim = ncfile.addDimension("lat", 3);
Dimension lonDim = ncfile.addDimension("lon", 4);
Dimension timeDim = ncfile.addDimension("time", -1, true, true, false);
// define Variables
Dimension[] dim3 = new Dimension[3];
dim3[0] = timeDim;
dim3[1] = latDim;
dim3[2] = lonDim;
// int rh(time, lat, lon) ;
// rh:long_name="relative humidity" ;
// rh:units = "percent" ;
ncfile.addVariable("rh", DataType.INT, dim3);
ncfile.addVariableAttribute("rh", "long_name", "relative humidity");
ncfile.addVariableAttribute("rh", "units", "percent");
// test attribute array
ArrayInt.D1 valid_range = new ArrayInt.D1(2);
valid_range.set(0, 0);
valid_range.set(1,100);
ncfile.addVariableAttribute("rh", "range", valid_range);
ncfile.addVariableAttribute( "rh", "valid_range", Array.factory(new
double[] {0d, 100d}) );
// double T(time, lat, lon) ;
// T:long_name="surface temperature" ;
// T:units = "degC" ;
ncfile.addVariable("T", DataType.DOUBLE, dim3);
ncfile.addVariableAttribute("T", "long_name", "surface temperature");
ncfile.addVariableAttribute("T", "units", "degC");
// float lat(lat) ;
// lat:units = "degrees_north" ;
ncfile.addVariable("lat", DataType.FLOAT, new Dimension[] {latDim});
ncfile.addVariableAttribute("lat", "units", "degrees_north");
// float lon(lon) ;
// lon:units = "degrees_east" ;
ncfile.addVariable("lon", DataType.FLOAT, new Dimension[] {lonDim});
ncfile.addVariableAttribute("lon", "units", "degrees_east");
// int time(time) ;
// time:units = "hours" ;
ncfile.addVariable("time", DataType.INT, new Dimension[] {timeDim});
ncfile.addVariableAttribute("time", "units", "hours");
// :title = "Example Data" ;
ncfile.addGlobalAttribute("title", "Example Data");
// create the file
try {
ncfile.create();
} catch (IOException e) {
System.err.println("ERROR creating file");
assert(false);
}
if (dumpAfterCreate) System.out.println( "ncfile = "+ ncfile);
Variable v = ncfile.findTopVariable("rh");
assert v != null;
assert v.isUnlimited();
// write the RH data one value at a time to an Array
int[][][] rhData = {{{ 1, 2, 3, 4}, { 5, 6, 7, 8}, { 9, 10, 11, 12}},
{{21, 22, 23, 24}, {25, 26, 27, 28}, {29, 30, 31, 32}}};
ArrayInt rhA = new ArrayInt.D3(2, latDim.getLength(), lonDim.getLength());
Index ima = rhA.getIndex();
// write
for (int i=0; i<2; i++)
for (int j=0; j<latDim.getLength(); j++)
for (int k=0; k<lonDim.getLength(); k++)
rhA.setInt(ima.set(i,j,k), rhData[i][j][k]);
// write rhData out to disk
try {
ncfile.write("rh", rhA);
} catch (IOException e) {
System.err.println("ERROR writing file");
assert(false);
} catch (InvalidRangeException e) {
e.printStackTrace();
assert(false);
}
// Here's an Array approach to set the values of T all at once.
double[][][] tData = {
{{ 1., 2, 3, 4}, {2., 4, 6, 8}, { 3., 6, 9, 12}},
{{2.5, 5, 7.5, 10}, {5., 10, 15, 20}, {7.5, 15, 22.5, 30}}
};
try {
ncfile.write("T", Array.factory(tData));
} catch (IOException e) {
System.err.println("ERROR writing file");
assert(false);
} catch (InvalidRangeException e) {
e.printStackTrace();
assert(false);
}
// Store the rest of variable values
try {
ncfile.write("lat", Array.factory(new float[] {41, 40, 39}));
ncfile.write("lon", Array.factory(new float[] {-109, -107, -105, -103}));
ncfile.write("time", Array.factory(new int[] {6, 18}));
} catch (IOException e) {
System.err.println("ERROR writing file");
assert(false);
} catch (InvalidRangeException e) {
e.printStackTrace();
assert(false);
}
// test reading without closing and reopening
try {
/* Get the value of the global attribute named "title" */
String title = ncfile.findAttValueIgnoreCase( null, "title", "N/A");
/* Read the latitudes into an array of double.
This works regardless of the external
type of the "lat" variable. */
Variable lat = ncfile.findVariable("lat");
assert(lat.getRank() == 1); // make sure it's 1-dimensional
int nlats = lat.getShape()[0]; // number of latitudes
double [] lats = new double[nlats]; // where to put them
Array values = lat.read(); // read all into memory
ima = values.getIndex(); // index array to specify which value
for (int ilat = 0; ilat < nlats; ilat++) {
lats[ilat] = values.getDouble(ima.set0(ilat));
}
/* Read units attribute of lat variable */
String latUnits = ncfile.findAttValueIgnoreCase( lat, "units", "N/A");
assert( latUnits.equals("degrees_north"));
/* Read the longitudes. */
Variable lon = ncfile.findVariable("lon");
values = lon.read();
assert( values instanceof ArrayFloat.D1);
ArrayFloat.D1 fa = (ArrayFloat.D1) values;
assert ( TestAll.closeEnough(fa.get(0), -109.0f)) : fa.get(0);
assert ( TestAll.closeEnough(fa.get(1), -107.0f)) : fa.get(1);
assert ( TestAll.closeEnough(fa.get(2), -105.0f)) : fa.get(2);
assert ( TestAll.closeEnough(fa.get(3), -103.0f)) : fa.get(3);
/* Now we can just use the MultiArray to access values, or
we can copy the MultiArray elements to another array with
toArray(), or we can get access to the MultiArray storage
without copying. Each of these approaches to accessing
the data are illustrated below. */
/* Whats the time dimensin length ? */
Dimension td = ncfile.findDimension("time");
assert td.getLength() == 2;
/* Read the times: unlimited dimension */
Variable time = ncfile.findVariable("time");
Array timeValues = time.read();
assert( timeValues instanceof ArrayInt.D1);
ArrayInt.D1 ta = (ArrayInt.D1) timeValues;
assert ( ta.get(0) == 6) : ta.get(0);
assert ( ta.get(1) == 18) : ta.get(1);
/* Read the relative humidity data */
Variable rh = ncfile.findVariable("rh");
Array rhValues = rh.read();
assert( rhValues instanceof ArrayInt.D3);
ArrayInt.D3 rha = (ArrayInt.D3) rhValues;
int[] shape = rha.getShape();
for (int i=0; i<shape[0]; i++) {
for (int j=0; j<shape[1]; j++) {
for (int k=0; k<shape[2]; k++) {
int want = 20*i + 4*j + k+1;
int val = rha.get(i, j, k);
//System.out.println(" "+i+" "+j+" "+k+" "+want+" "+val);
assert ( want == val) : val;
}
}
}
/* Read the temperature data */
Variable t = ncfile.findVariable("T");
Array tValues = t.read();
assert( tValues instanceof ArrayDouble.D3);
ArrayDouble.D3 Ta = (ArrayDouble.D3) tValues;
assert TestAll.closeEnough( Ta.get(0,0,0), 1.0f) : Ta.get(0, 0, 0);
assert TestAll.closeEnough( Ta.get(1,1,1), 10.0f) : Ta.get(1, 1, 1);
/* Read subset of the temperature data */
tValues = t.read(new int[3], new int[] {2,2,2});
assert( tValues instanceof ArrayDouble.D3);
Ta = (ArrayDouble.D3) tValues;
assert TestAll.closeEnough( Ta.get(0,0,0), 1.0f) : Ta.get(0, 0, 0);
assert TestAll.closeEnough( Ta.get(1,1,1), 10.0f) : Ta.get(1, 1, 1);
} catch (InvalidRangeException e) {
e.printStackTrace();
} catch (java.io.IOException e) {
e.printStackTrace();
}
// all done
try {
ncfile.flush();
ncfile.close();
} catch (IOException e) {
System.err.println("ERROR writing file");
assert(false);
}
System.out.println( "**** TestWriteRecord done");
}
// make an example writing records
public void testNC3WriteWithRecord() throws IOException {
NetcdfFileWriteable ncfile = new
NetcdfFileWriteable("C:/temp/writeRecordExample.nc", false);
// define dimensions, including unlimited
Dimension latDim = ncfile.addDimension("lat", 64);
Dimension lonDim = ncfile.addDimension("lon", 128);
Dimension timeDim = ncfile.addDimension("time", -1, true, true, false);
// define Variables
Dimension[] dim3 = new Dimension[3];
dim3[0] = timeDim;
dim3[1] = latDim;
dim3[2] = lonDim;
// double T(time, lat, lon) ;
// T:long_name="surface temperature" ;
// T:units = "degC" ;
ncfile.addVariable("T", DataType.DOUBLE, dim3);
ncfile.addVariableAttribute("T", "long_name", "surface temperature");
ncfile.addVariableAttribute("T", "units", "degC");
// float lat(lat) ;
// lat:units = "degrees_north" ;
ncfile.addVariable("lat", DataType.FLOAT, new Dimension[] {latDim});
ncfile.addVariableAttribute("lat", "units", "degrees_north");
// float lon(lon) ;
// lon:units = "degrees_east" ;
ncfile.addVariable("lon", DataType.FLOAT, new Dimension[] {lonDim});
ncfile.addVariableAttribute("lon", "units", "degrees_east");
// int time(time) ;
// time:units = "hours" ;
ncfile.addVariable("time", DataType.INT, new Dimension[] {timeDim});
ncfile.addVariableAttribute("time", "units", "hours");
// :title = "Example Data" ;
ncfile.addGlobalAttribute("title", "Example Data");
// create the file
try {
ncfile.create();
} catch (IOException e) {
System.err.println("ERROR creating file");
e.printStackTrace();
return;
}
System.out.println( "ncfile = "+ ncfile);
// now write one record at a time
Variable v = ncfile.findTopVariable("T");
ArrayDouble data = new ArrayDouble.D3(1, latDim.getLength(),
lonDim.getLength());
ArrayInt timeData = new ArrayInt.D1(1);
int[] origin = new int[v.getRank()];
int[] timeOrigin = new int[1];
for (int time=0; time<100; time++) {
// fill the data array
Index ima = data.getIndex();
for (int j=0; j<latDim.getLength(); j++)
for (int k=0; k<lonDim.getLength(); k++)
data.setDouble(ima.set(0,j,k), (double) time*j*k);
timeData.setInt( timeData.getIndex(), time);
// write to file
origin[0] = time;
timeOrigin[0] = time;
try {
ncfile.write("T", origin, data);
ncfile.write("time", timeOrigin, timeData);
} catch (IOException e) {
System.err.println("ERROR writing file");
} catch (InvalidRangeException e) {
e.printStackTrace();
}
}
// all done
try {
ncfile.close();
} catch (IOException e) {
System.err.println("ERROR writing file");
}
System.out.println( "**** TestWriteRecord done");
}
}
package ucar.nc2;
import junit.framework.*;
import ucar.ma2.*;
import java.io.*;
import java.util.*;
/** Test nc2 write JUnit framework. */
public class TestWrite extends TestCase {
private boolean show = false;
public TestWrite( String name) {
super(name);
}
public void testNC3Write() throws IOException {
String filename = TestNC2.topDir+"testWrite.nc";
NetcdfFileWriteable ncfile = new NetcdfFileWriteable(filename, false);
// define dimensions
Dimension latDim = ncfile.addDimension("lat", 64);
Dimension lonDim = ncfile.addDimension("lon", 128);
// define Variables
ArrayList dims = new ArrayList();
dims.add( latDim);
dims.add( lonDim);
ncfile.addVariable("temperature", DataType.DOUBLE, dims);
ncfile.addVariableAttribute("temperature", "units", "K");
int[] attValue = new int[3];
attValue[0] = 1;
attValue[1] = 2;
attValue[2] = 3;
Array data = Array.factory( int.class, new int [] {3}, attValue);
ncfile.addVariableAttribute("temperature", "scale", data);
ncfile.addVariableAttribute("temperature", "versionD", new Double(1.2));
ncfile.addVariableAttribute("temperature", "versionF", new Float(1.2));
ncfile.addVariableAttribute("temperature", "versionI", new Integer(1));
ncfile.addVariableAttribute("temperature", "versionS", new Short((short)2));
ncfile.addVariableAttribute("temperature", "versionB", new Byte((byte)3));
ncfile.addVariableAttribute("temperature", "versionString", "1.2");
// add string-valued variables
Dimension svar_len = ncfile.addDimension("svar_len", 80);
dims = new ArrayList();
dims.add( svar_len);
ncfile.addVariable("svar", DataType.CHAR, dims);
ncfile.addVariable("svar2", DataType.CHAR, dims);
// string array
Dimension names = ncfile.addDimension("names", 3);
ArrayList dima = new ArrayList();
dima.add(names);
dima.add(svar_len);
ncfile.addVariable("names", DataType.CHAR, dima);
ncfile.addVariable("names2", DataType.CHAR, dima);
// add global attributes
ncfile.addGlobalAttribute("yo", "face");
ncfile.addGlobalAttribute("versionD", new Double(1.2));
ncfile.addGlobalAttribute("versionF", new Float(1.2));
ncfile.addGlobalAttribute("versionI", new Integer(1));
ncfile.addGlobalAttribute("versionS", new Short((short)2));
ncfile.addGlobalAttribute("versionB", new Byte((byte)3));
// test some errors
try {
Array bad = Array.factory( ArrayList.class, new int[] {1});
ncfile.addGlobalAttribute("versionC", bad);
assert(false);
} catch (IllegalArgumentException e) {
assert(true);
}
// create the file
try {
ncfile.create();
} catch (IOException e) {
System.err.println("ERROR creating file "+ncfile.getLocation()+"\n"+e);
assert(false);
}
// write some data
ArrayDouble A = new ArrayDouble.D2(latDim.getLength(), lonDim.getLength());
int i,j;
Index ima = A.getIndex();
// write
for (i=0; i<latDim.getLength(); i++) {
for (j=0; j<lonDim.getLength(); j++) {
A.setDouble(ima.set(i,j), (double) (i*1000000+j*1000));
}
}
int[] origin = new int[2];
try {
ncfile.write("temperature", origin, A);
} catch (IOException e) {
System.err.println("ERROR writing file");
assert(false);
} catch (InvalidRangeException e) {
e.printStackTrace();
assert(false);
}
// write char variable
int[] origin1 = new int[1];
ArrayChar ac = new ArrayChar.D1(svar_len.getLength());
ima = ac.getIndex();
String val = "Testing 1-2-3";
for (j=0; j<val.length(); j++)
ac.setChar(ima.set(j), val.charAt(j));
try {
ncfile.write("svar", origin1, ac);
} catch (IOException e) {
System.err.println("ERROR writing Achar");
assert(false);
} catch (InvalidRangeException e) {
e.printStackTrace();
assert(false);
}
// write char variable as String
try {
ArrayChar ac2 = new ArrayChar.D1(svar_len.getLength());
ac2.setString( "Two pairs of ladies stockings!");
ncfile.write("svar2", origin1, ac2);
} catch (IOException e) {
System.err.println("ERROR writing Achar2");
assert(false);
} catch (InvalidRangeException e) {
e.printStackTrace();
assert(false);
}
// write String array
try {
ArrayChar ac2 = new ArrayChar.D2(names.getLength(), svar_len.getLength());
ima = ac2.getIndex();
ac2.setString( ima.set(0), "No pairs of ladies stockings!");
ac2.setString( ima.set(1), "One pair of ladies stockings!");
ac2.setString( ima.set(2), "Two pairs of ladies stockings!");
ncfile.write("names", origin, ac2);
} catch (IOException e) {
System.err.println("ERROR writing Achar3");
assert(false);
} catch (InvalidRangeException e) {
e.printStackTrace();
assert(false);
}
// write String array
try {
ArrayChar ac2 = new ArrayChar.D2(names.getLength(), svar_len.getLength());
ima = ac2.getIndex();
ac2.setString( 0, "0 pairs of ladies stockings!");
ac2.setString( 1, "1 pair of ladies stockings!");
ac2.setString( 2, "2 pairs of ladies stockings!");
ncfile.write("names2", origin, ac2);
} catch (IOException e) {
System.err.println("ERROR writing Achar4");
assert(false);
} catch (InvalidRangeException e) {
e.printStackTrace();
assert(false);
}
try {
ncfile.flush();
} catch (IOException e) {
e.printStackTrace();
assert(false);
}
if (show) System.out.println( "ncfile = "+ ncfile);
//////////////////////////////////////////////////////////////////////
// test reading without closing the file
// read entire array
Variable temp = ncfile.findVariable("temperature");
assert (null != temp);
Array tA = temp.read();
assert (tA.getRank() == 2);
ima = tA.getIndex();
int[] shape = tA.getShape();
for (i=0; i<shape[0]; i++) {
for (j=0; j<shape[1]; j++) {
assert( tA.getDouble(ima.set(i,j)) == (double) (i*1000000+j*1000));
}
}
// read part of array
int[] origin2 = new int[2];
int[] shape2 = new int[2];
shape2[0] = 1;
shape2[1] = temp.getShape()[1];
try {
tA = temp.read(origin2, shape2);
} catch (InvalidRangeException e) {
System.err.println("ERROR reading file " +e);
assert(false);
return;
} catch (IOException e) {
System.err.println("ERROR reading file");
assert(false);
return;
}
assert (tA.getRank() == 2);
for (j=0; j<shape2[1]; j++) {
assert( tA.getDouble(ima.set(0,j)) == (double) (j*1000));
}
// rank reduction
Array Areduce = tA.reduce();
Index ima2 = Areduce.getIndex();
assert (Areduce.getRank() == 1);
for (j=0; j<shape2[1]; j++) {
assert( Areduce.getDouble(ima2.set(j)) == (double) (j*1000));
}
// read char variable
Variable c = null;
assert(null != (c = ncfile.findVariable("svar")));
try {
tA = c.read();
} catch (IOException e) {
assert(false);
}
assert(tA instanceof ArrayChar);
ArrayChar achar = (ArrayChar) tA;
String sval = achar.getString(ac.getIndex());
assert sval.equals("Testing 1-2-3") : sval;
//System.out.println( "val = "+ val);
// read char variable 2
Variable c2 = null;
assert(null != (c2 = ncfile.findVariable("svar2")));
try {
tA = c2.read();
} catch (IOException e) {
assert(false);
}
assert(tA instanceof ArrayChar);
ArrayChar ac2 = (ArrayChar) tA;
assert(ac2.getString().equals("Two pairs of ladies stockings!"));
// read String Array
Variable c3 = null;
assert(null != (c3 = ncfile.findVariable("names")));
try {
tA = c3.read();
} catch (IOException e) {
assert(false);
}
assert(tA instanceof ArrayChar);
ArrayChar ac3 = (ArrayChar) tA;
ima = ac3.getIndex();
assert(ac3.getString(ima.set(0)).equals("No pairs of ladies stockings!"));
assert(ac3.getString(ima.set(1)).equals("One pair of ladies stockings!"));
assert(ac3.getString(ima.set(2)).equals("Two pairs of ladies stockings!"));
// read String Array - 2
Variable c4 = null;
assert(null != (c4 = ncfile.findVariable("names2")));
try {
tA = c4.read();
} catch (IOException e) {
assert(false);
}
assert(tA instanceof ArrayChar);
ArrayChar ac4 = (ArrayChar) tA;
ima = ac4.getIndex();
assert(ac4.getString(0).equals("0 pairs of ladies stockings!"));
assert(ac4.getString(1).equals("1 pair of ladies stockings!"));
assert(ac4.getString(2).equals("2 pairs of ladies stockings!"));
/////////////////////////////////////////////////////////////////////
// all done
try {
ncfile.close();
} catch (IOException e) {
e.printStackTrace();
assert(false);
}
System.out.println( "*****************Test Write done on "+filename);
}
}
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