ncsa.hdf.object
Class Dataset

java.lang.Object
  ncsa.hdf.object.HObject
      ncsa.hdf.object.Dataset

All Implemented Interfaces:

java.io.Serializable, DataFormat

Direct Known Subclasses:

CompoundDS, ScalarDS

public abstract class Dataset
extends HObject

The abstract class provides general APIs to create and manipulate dataset objects, and retrieve dataset properties datatype and dimension sizes.

This class provides two convenient functions, read()/write(), to read/write data values. Reading/writing data may take many library calls if we use the library APIs directly. The read() and write functions hide all the details of these calls from users.

Version:

1.1 9/4/2007

Author:

Peter X. Cao

See Also:

ScalarDS, CompoundDS, Serialized Form

Field Summary

Fields inherited from class ncsa.hdf.object.HObject

separator, serialVersionUID

Constructor Summary

Dataset(FileFormat theFile, java.lang.String name, java.lang.String path)
Constructs a Dataset object with a given file, name and path.

Dataset(FileFormat theFile, java.lang.String name, java.lang.String path, long[] oid)
Deprecated. Not for public use in the future.
Using Dataset(FileFormat, String, String)

Method Summary

static java.lang.String[]	byteToString(byte[] bytes, int length) Converts an array of bytes into an array of Strings for a fixed string dataset.
void	clear() Clears memory held by the dataset, such as data buffer.
void	clearData() Clears the data buffer in memory and to force the next read() to load data from file.
static java.lang.Object	convertFromUnsignedC(java.lang.Object data_in) Deprecated. Not for public use in the future. Using convertFromUnsignedC(Object, Object)
static java.lang.Object	convertFromUnsignedC(java.lang.Object data_in, java.lang.Object data_out) Converts one-dimension array of unsigned C-type integers to a new array of appropriate Java integer in memory.
static java.lang.Object	convertToUnsignedC(java.lang.Object data_in) Deprecated. Not for public use in the future. Using convertToUnsignedC(Object, Object)
static java.lang.Object	convertToUnsignedC(java.lang.Object data_in, java.lang.Object data_out) Converts the array of converted unsigned integer back to unsigned C-type integer data in memory.
abstract Dataset	copy(Group pgroup, java.lang.String name, long[] dims, java.lang.Object data) Creates a new dataset and writes the data buffer to the new dataset.
long[]	getChunkSize() Returns the array that contains the dimension sizes of the chunk of the dataset.
java.lang.String	getCompression() Returns the string representation of compression information.
boolean	getConvertByteToString() Returns the flag that indicates if a byte array is converted to a string array..
java.lang.Object	getData() Returns the data buffer of the dataset in memory.
abstract Datatype	getDatatype() Returns the datatype object of the dataset.
java.lang.String[]	getDimNames() Returns the array of strings that represent the dimension names.
long[]	getDims() Returns the array that contins the dimension sizes of the dataset.
int	getHeight() Returns the dimension size of the vertical axis.
long[]	getMaxDims() Returns the array that contins the max dimension sizes of the dataset.
int	getRank() Returns the rank (number of dimensions) of the dataset.
long[]	getSelectedDims() Returns the dimension sizes of the selected subset.
int[]	getSelectedIndex() Returns the indices of display order.
int	getSize(int tid) Returns the size in bytes of a given datatype.
long[]	getStartDims() Returns the starting position of a selected subset.
long[]	getStride() Returns the selectedStride of the selected dataset.
int	getWidth() Returns the size of dimension of the horizontal axis.
abstract void	init() Retrieves datatype and dataspace information from file and sets the dataset in memory.
boolean	isEnumConverted() Get flag that indicate if enum data is converted to strings.
boolean	isString(int tid) Checks if a given datatype is a string.
abstract java.lang.Object	read() Reads the data from file.
abstract byte[]	readBytes() Reads the raw data of the dataset from file to a byte array.
void	setConvertByteToString(boolean b) Sets the flag that indicates if a byte array is converted to a string array.
void	setData(java.lang.Object d) Deprecated. Not for public use in the future. setData() is not safe to use because it changes memory buffer of the dataset object. Dataset operation such as write/read will fail if the buffer type or size is changed.
void	setEnumConverted(boolean b) Set flag that indicate if enum data is converted to strings.
static byte[]	stringToByte(java.lang.String[] strings, int length) Converts a string array into an array of bytes for a fixed string dataset.
void	write() Writes the memory buffer of this dataset to file.
abstract void	write(java.lang.Object buf) Writes a memory buffer to the dataset in file.

Methods inherited from class ncsa.hdf.object.HObject

close, equalsOID, getFID, getFile, getFileFormat, getFullName, getLinkTargetObjName, getName, getOID, getPath, open, setLinkTargetObjName, setName, setPath, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface ncsa.hdf.object.DataFormat

getMetadata, hasAttribute, removeMetadata, writeMetadata

Constructor Detail

Dataset

public Dataset(FileFormat theFile,
               java.lang.String name,
               java.lang.String path)

Constructs a Dataset object with a given file, name and path.

Parameters:

theFile - the file that contains the dataset.

name - the name of the Dataset, e.g. "dset1".

path - the full group path of this Dataset, e.g. "/arrays/".

Dataset

@Deprecated
public Dataset(FileFormat theFile,
                          java.lang.String name,
                          java.lang.String path,
                          long[] oid)

Deprecated. Not for public use in the future.
Using Dataset(FileFormat, String, String)

Method Detail

clear

public void clear()

Clears memory held by the dataset, such as data buffer.

init

public abstract void init()

Retrieves datatype and dataspace information from file and sets the dataset in memory.

The init() is designed to support lazy operation in dataset object. When a data object is retrieved from file, the datatype, dataspace and raw data are not loaded into memory. When it is asked to read the raw data from file, init() is first called to get the datatype and dataspace information, then load the raw data from file.

init() is also used to reset selection of a dataset (start, stride and count) to the default, which is the entire dataset for 1D or 2D datasets. In the following example, init() at step 1) retrieve datatype and dataspace information from file. getData() at step 3) read only one data point. init() at step 4) reset the selection to the whole dataset. getData() at step 4) reads the values of whole dataset into memory.

 dset = (Dataset) file.get(NAME_DATASET);
 
 // 1) get datatype and dataspace information from file
 dset.init();
 rank = dset.getRank(); // rank = 2, a 2D dataset
 count = dset.getSelectedDims();
 start = dset.getStartDims();
 dims = dset.getDims();
 
 // 2) select only one data point
 for (int i = 0; i < rank; i++) {
     start[0] = 0;
     count[i] = 1;
 }
 
 // 3)  read one data point
 data = dset.getData();
 
 // 4)  reset to select the whole dataset
 dset.init();
 
 // 5) clean the memory data buffer
 dset.clearData();
 
 // 6) Read the whole dataset
 data = dset.getData();
 

getRank

public final int getRank()

Returns the rank (number of dimensions) of the dataset.

Returns:

the number of dimensions of the dataset.

getDims

public final long[] getDims()

Returns the array that contins the dimension sizes of the dataset.

Returns:

the dimension sizes of the dataset.

getMaxDims

public final long[] getMaxDims()

Returns the array that contins the max dimension sizes of the dataset.

Returns:

the max dimension sizes of the dataset.

getSelectedDims

public final long[] getSelectedDims()

Returns the dimension sizes of the selected subset.

The SelectedDims is the number of data points of the selected subset. Applications can use this array to change the size of selected subset. The select size must be less than or equal to the current dimension size. Combined with the starting position, selected sizes and stride, the subset of a rectangle selection is fully defined.

For example, a 4 X 5 dataset

     0,  1,  2,  3,  4
    10, 11, 12, 13, 14
    20, 21, 22, 23, 24
    30, 31, 32, 33, 34
 long[] dims = {4, 5};
 long[] startDims = {1, 2};
 long[] selectedDims = {3, 3};
 long[] selectedStride = {1, 1};
 then the following subset is selected by the startDims and selectedDims
     12, 13, 14
     22, 23, 24
     32, 33, 34
 

Returns:

the dimension sizes of the selected subset.

getStartDims

public final long[] getStartDims()

Returns the starting position of a selected subset.

Applications can use this array to change the starting position of a selection. Combined with the selected dimensions, selected sizes and stride, the subset of a rectangle selection is fully defined.

For example, a 4 X 5 dataset

     0,  1,  2,  3,  4
    10, 11, 12, 13, 14
    20, 21, 22, 23, 24
    30, 31, 32, 33, 34
 long[] dims = {4, 5};
 long[] startDims = {1, 2};
 long[] selectedDims = {3, 3};
 long[] selectedStride = {1, 1};
 then the following subset is selected by the startDims and selectedDims
     12, 13, 14
     22, 23, 24
     32, 33, 34
 

Returns:

the starting position of a selected subset.

getStride

public final long[] getStride()

Returns the selectedStride of the selected dataset.

Applications can use this array to change how many elements to move in each dimension. Combined with the starting position and selected sizes, the subset of a rectangle selection is defined.

For example, a 4 X 5 dataset

     0,  1,  2,  3,  4
    10, 11, 12, 13, 14
    20, 21, 22, 23, 24
    30, 31, 32, 33, 34
 long[] dims = {4, 5};
 long[] startDims = {0, 0};
 long[] selectedDims = {2, 2};
 long[] selectedStride = {2, 3};
 then the following subset is selected by the startDims and selectedDims
     0,   3
     20, 23
 

setConvertByteToString

public final void setConvertByteToString(boolean b)

Sets the flag that indicates if a byte array is converted to a string array.

In a string dataset, the raw data from file is stored in a byte array. By default, this byte array is converted to an array of strings. For a large dataset (e.g. more than one million strings), the converson takes a long time and requires a lot of memory space to store the strings. At some applications, such a conversion can be delayed. For example, A GUI application may convert only part of the strings that are visible to the users, not the entire data array.

setConvertByteToString(boolean b) allows users to set the flag so that applications can choose to perform the byte-to-string conversion or not. If the flag is set to false, the getData() returns a array of byte instead of an array of strings.

Parameters:

b - convert bytes to strings if b is true; otherwise, if false, do not convert bytes to strings.

getConvertByteToString

public final boolean getConvertByteToString()

Returns the flag that indicates if a byte array is converted to a string array..

Returns:

true if byte array is converted to string; otherwise, returns false if there is no conversion.

read

public abstract java.lang.Object read()
                               throws java.lang.Exception,
                                      java.lang.OutOfMemoryError

Reads the data from file.

read() reads the data from file to a memory buffer and returns the memory buffer. The dataset object does not hold the memobry buffer. To store the memory buffer in the dataset object, one must call getData().

By default, the whole dataset is read into memory. Users can also select subset to read. Subsetting is done in an implicit way.

How to Select a Subset

A selection is specified by three arrays: start, stride and count.

1. start: offset of a selection
2. stride: determining how many elements to move in each dimension
3. count: number of elements to select in each dimension

getStartDims(), getStartDims() and getSelectedDims() returns the start, stride and count arrays respectively. Applications can make a selection by changing the values of the arrays.

The following example shows how to make a subset. In the example, the dataset is a 4-dimensional array of [200][100][50][10], i.e. dims[0]=200; dims[1]=100; dims[2]=50; dims[3]=10;
We want to select every other data point in dims[1] and dims[2]

 int rank = dataset.getRank(); // number of dimension of the dataset
 long[] dims = dataset.getDims(); // the dimension sizes of the dataset
 long[] selected = dataset.getSelectedDims(); // the selected size of the dataet
 long[] start = dataset.getStartDims(); // the off set of the selection
 long[] stride = dataset.getStride(); // the stride of the dataset
 int[] selectedIndex = dataset.getSelectedIndex(); // the selected dimensions for display
 
 // select dim1 and dim2 as 2D data for display,and slice through dim0
 selectedIndex[0] = 1;
 selectedIndex[1] = 2;
 selectedIndex[1] = 0;
 
 // reset the selection arrays
 for (int i = 0; i < rank; i++) {
     start[i] = 0;
     selected[i] = 1;
     stride[i] = 1;
 }
 
 // set stride to 2 on dim1 and dim2 so that every other data points are selected.
 stride[1] = 2;
 stride[2] = 2;
 
 // set the selection size of dim1 and dim2
 selected[1] = dims[1] / stride[1];
 selected[2] = dims[1] / stride[2];
 
 // when dataset.getData() is called, the slection above will be used since
 // the dimension arrays are passed by reference. Changes of these arrays
 // outside the dataset object directly change the values of these array
 // in the dataset object.
 

For ScalarDS, the memory data buffer is an one-dimensional array of byte, short, int, float, double or String type based on the datatype of the dataset.

For CompoundDS, the meory data object is an java.util.List object. Each element of the list is a data array that corresponds to a compound field.

For example, if compound dataset "comp" has the following nested structure, and memeber datatypes

 comp --> m01 (int)
 comp --> m02 (float)
 comp --> nest1 --> m11 (char)
 comp --> nest1 --> m12 (String)
 comp --> nest1 --> nest2 --> m21 (long)
 comp --> nest1 --> nest2 --> m22 (double)
 

getData() returns a list of six arrays: {int[], float[], char[], Stirng[], long[] and double[]}.

Returns:

the data read from file.

Throws:

java.lang.Exception

java.lang.OutOfMemoryError

See Also:

#getData()}

readBytes

public abstract byte[] readBytes()
                          throws java.lang.Exception

Reads the raw data of the dataset from file to a byte array.

readBytes() reads raw data to an array of bytes instead of array of its datatype. For example, for an one-dimension 32-bit integer dataset of size 5, the readBytes() returns of a byte array of size 20 instead of an int array of 5.

readBytes() can be used to copy data from one dataset to another efficiently because the raw data is not converted to its native type, it saves memory space and CPU time.

Returns:

the byte array of the raw data.

Throws:

java.lang.Exception

write

public abstract void write(java.lang.Object buf)
                    throws java.lang.Exception

Writes a memory buffer to the dataset in file.

Parameters:

buf - the data to write

Throws:

java.lang.Exception

write

public final void write()
                 throws java.lang.Exception

Writes the memory buffer of this dataset to file.

Throws:

java.lang.Exception

copy

public abstract Dataset copy(Group pgroup,
                             java.lang.String name,
                             long[] dims,
                             java.lang.Object data)
                      throws java.lang.Exception

Creates a new dataset and writes the data buffer to the new dataset.

This function allows applications to create a new dataset for a given data buffer. For example, users can select a specific interesting part from a large image and create a new image with the selection.

The new dataset retains the datatype and dataset creation properties of this dataset.

Parameters:

pgroup - the group which the dataset is copied to.

name - the name of the new dataset.

dims - the dimension sizes of the the new dataset.

data - the data values of the subset to be copied.

Returns:

the new dataset.

Throws:

java.lang.Exception

getDatatype

public abstract Datatype getDatatype()

Returns the datatype object of the dataset.

Returns:

the datatype object of the dataset.

getData

public final java.lang.Object getData()
                               throws java.lang.Exception,
                                      java.lang.OutOfMemoryError

Returns the data buffer of the dataset in memory.

If data is already loaded into memory, returns the data; otherwise, calls read() to read data from file into a memory buffer and returns the memory buffer.

By default, the whole dataset is read into memory. Users can also select subset to read. Subsetting is done in an implicit way.

How to Select a Subset

A selection is specified by three arrays: start, stride and count.

1. start: offset of a selection
2. stride: determining how many elements to move in each dimension
3. count: number of elements to select in each dimension

getStartDims(), getStartDims() and getSelectedDims() returns the start, stride and count arrays respectively. Applications can make a selection by changing the values of the arrays.

The following example shows how to make a subset. In the example, the dataset is a 4-dimensional array of [200][100][50][10], i.e. dims[0]=200; dims[1]=100; dims[2]=50; dims[3]=10;
We want to select every other data point in dims[1] and dims[2]

 int rank = dataset.getRank(); // number of dimension of the dataset
 long[] dims = dataset.getDims(); // the dimension sizes of the dataset
 long[] selected = dataset.getSelectedDims(); // the selected size of the dataet
 long[] start = dataset.getStartDims(); // the off set of the selection
 long[] stride = dataset.getStride(); // the stride of the dataset
 int[] selectedIndex = dataset.getSelectedIndex(); // the selected dimensions for display
 
 // select dim1 and dim2 as 2D data for display,and slice through dim0
 selectedIndex[0] = 1;
 selectedIndex[1] = 2;
 selectedIndex[1] = 0;
 
 // reset the selection arrays
 for (int i = 0; i < rank; i++) {
     start[i] = 0;
     selected[i] = 1;
     stride[i] = 1;
 }
 
 // set stride to 2 on dim1 and dim2 so that every other data points are selected.
 stride[1] = 2;
 stride[2] = 2;
 
 // set the selection size of dim1 and dim2
 selected[1] = dims[1] / stride[1];
 selected[2] = dims[1] / stride[2];
 
 // when dataset.getData() is called, the slection above will be used since
 // the dimension arrays are passed by reference. Changes of these arrays
 // outside the dataset object directly change the values of these array
 // in the dataset object.
 

For ScalarDS, the memory data buffer is an one-dimensional array of byte, short, int, float, double or String type based on the datatype of the dataset.

For CompoundDS, the meory data object is an java.util.List object. Each element of the list is a data array that corresponds to a compound field.

For example, if compound dataset "comp" has the following nested structure, and memeber datatypes

 comp --> m01 (int)
 comp --> m02 (float)
 comp --> nest1 --> m11 (char)
 comp --> nest1 --> m12 (String)
 comp --> nest1 --> nest2 --> m21 (long)
 comp --> nest1 --> nest2 --> m22 (double)
 

getData() returns a list of six arrays: {int[], float[], char[], Stirng[], long[] and double[]}.

Returns:

the memory buffer of the dataset.

Throws:

java.lang.Exception

java.lang.OutOfMemoryError

setData

@Deprecated
public final void setData(java.lang.Object d)

Deprecated. Not for public use in the future.

setData() is not safe to use because it changes memory buffer of the dataset object. Dataset operation such as write/read will fail if the buffer type or size is changed.

clearData

public void clearData()

Clears the data buffer in memory and to force the next read() to load data from file.

The function read() loads data from file into memory only if the data is not read. If data is already in memory, read() just returns the memory buffer. Sometimes we want to force read() to re-read data from file. For example, when the selection is changed, we need to re-read the data. clearData() clears the current memory buffer and force the read() to load the data from file.

See Also:

getData(), read()

getHeight

public final int getHeight()

Returns the dimension size of the vertical axis.

This function is used by GUI applications such as HDFView. GUI applications display a dataset in a 2D table or 2D image. The display order is specified by the index array of selectedIndex as follow:

selectedIndex[0] -- height

The vertical axis

selectedIndex[1] -- width

The horizontal axis

selectedIndex[2] -- depth

The depth axis is used for 3 or more dimensional datasets.

Applications can use getSelectedIndex() to access and change the display order. For example, in a 2D dataset of 200x50 (dim0=200, dim1=50), the following code will set the height=200 and width=50.

 long[] selectedIndex = dataset.getSelectedIndex();
 selectedIndex[0] = 0;
 selectedIndex[1] = 1;
 

Returns:

the size of dimension of the vertical axis.

See Also:

getSelectedIndex(), getWidth()

getWidth

public final int getWidth()

Returns the size of dimension of the horizontal axis.

This function is used by GUI applications such as HDFView. GUI applications display dataset a 2D Table or 2D Image. The display order is specified by the index array of selectedIndex as follow:

selectedIndex[0] -- height

The vertical axis

selectedIndex[1] -- width

The horizontal axis

selectedIndex[2] -- depth

The depth axis, which is used for 3 or more dimension datasets.

Applications can use getSelectedIndex() to access and change the display order. For example, in a 2D dataset of 200x50 (dim0=200, dim1=50), the following code will set the height=200 and width=100.

 long[] selectedIndex = dataset.getSelectedIndex();
 selectedIndex[0] = 0;
 selectedIndex[1] = 1;
 

Returns:

the size of dimension of the horizontal axis.

See Also:

getSelectedIndex(), getHeight()

getSelectedIndex

public final int[] getSelectedIndex()

Returns the indices of display order.

selectedIndex[] is provided for two purpose:

1. selectedIndex[] is used to indicate the order of dimensions for display. selectedIndex[0] is for the row, selectedIndex[1] is for the column and selectedIndex[2] for the depth.

   For example, for a four dimesion dataset, if selectedIndex[] = {1, 2, 3}, then dim[1] is selected as row index, dim[2] is selected as column index and dim[3] is selected as depth index.

2. selectedIndex[] is also used to select dimensions for display for datasets with three or more dimensions. We assume that applications such as HDFView can only display data values up to three dimension (2D spreadsheet/image with a third dimension which the 2D spreadsheet/image is selected from). For dataset with more than three dimensions, we need selectedIndex[] to tell applications which three dimensions are chosen for display.
   For example, for a four dimesion dataset, if selectedIndex[] = {1, 2, 3}, then dim[1] is selected as row index, dim[2] is selected as column index and dim[3] is selected as depth index. dim[0] is not selected. Its location is fixed at 0 by default.

Returns:

the array of the indices of display order.

getCompression

public final java.lang.String getCompression()

Returns the string representation of compression information.

For example, "SZIP: Pixels per block = 8: H5Z_FILTER_CONFIG_DECODE_ENABLED".

Returns:

the string representation of compression information.

getChunkSize

public final long[] getChunkSize()

Returns the array that contains the dimension sizes of the chunk of the dataset. Returns null if the dataset is not chunked.

Returns:

the array of chunk sizes or returns null if the dataset is not chunked.

convertFromUnsignedC

@Deprecated
public static java.lang.Object convertFromUnsignedC(java.lang.Object data_in)

Deprecated. Not for public use in the future.
Using convertFromUnsignedC(Object, Object)

convertFromUnsignedC

public static java.lang.Object convertFromUnsignedC(java.lang.Object data_in,
                                                    java.lang.Object data_out)

Converts one-dimension array of unsigned C-type integers to a new array of appropriate Java integer in memory.

Since Java does not support unsigned integer, values of unsigned C-type integers must be converted into its appropriate Java integer. Otherwise, the data value will not displayed correctly. For example, if an unsigned C byte, x = 200, is stored into an Java byte y, y will be -56 instead of the correct value of 200.

Unsigned C integers are upgrade to Java integers according to the following table:

Mapping Unsigned C Integers to Java Integers

Unsigned C Integer	JAVA Integer
unsigned byte	signed short
unsigned short	signed int
unsigned int	signed long
unsigned long	signed long

NOTE: this conversion cannot deal with unsigned 64-bit integers. Therefore, the values of unsigned 64-bit dataset may be wrong in Java application.

If memory data of unsigned integers is converted by convertFromUnsignedC(), convertToUnsignedC() must be called to convert the data back to unsigned C before data is written into file.

Parameters:

data_in - the input 1D array of the unsigned C-type integers.

data_out - the output converted (or upgraded) 1D array of Java integers.

Returns:

the upgraded 1D array of Java integers.

See Also:

convertToUnsignedC(Object, Object)

convertToUnsignedC

@Deprecated
public static java.lang.Object convertToUnsignedC(java.lang.Object data_in)

Deprecated. Not for public use in the future.
Using convertToUnsignedC(Object, Object)

convertToUnsignedC

public static java.lang.Object convertToUnsignedC(java.lang.Object data_in,
                                                  java.lang.Object data_out)

Converts the array of converted unsigned integer back to unsigned C-type integer data in memory.

If memory data of unsigned integers is converted by convertFromUnsignedC(), convertToUnsignedC() must be called to convert the data back to unsigned C before data is written into file.

Parameters:

data_in - the input array of the Java integer.

data_out - the output array of the unsigned C-type integer.

Returns:

the converted data of unsigned C-type integer array.

See Also:

convertFromUnsignedC(Object, Object)

byteToString

public static final java.lang.String[] byteToString(byte[] bytes,
                                                    int length)

Converts an array of bytes into an array of Strings for a fixed string dataset.

A C-string is an array of chars while an Java String is an object. When a string dataset is read into Java application, the data is stored in an array of Java bytes. byteToString() is used to convert the array of bytes into array of Java strings so that applications can display and modify the data content.

For example, the content of a two element C string dataset is {"ABC", "abc"}. Java applications will read the data into an byte array of {65, 66, 67, 97, 98, 99). byteToString(bytes, 3) returns an array of Java String of strs[0]="ABC", and strs[1]="abc".

If memory data of strings is converted to Java Strings, stringToByte() must be called to convert the memory data back to byte array before data is written to file.

Parameters:

bytes - the array of bytes to convert.

length - the length of string.

Returns:

the array of Java String.

See Also:

stringToByte(String[], int)

stringToByte

public static final byte[] stringToByte(java.lang.String[] strings,
                                        int length)

Converts a string array into an array of bytes for a fixed string dataset.

If memory data of strings is converted to Java Strings, stringToByte() must be called to convert the memory data back to byte array before data is written to file.

Parameters:

strings - the array of string.

length - the length of string.

Returns:

the array of bytes.

See Also:

byteToString(byte[] bytes, int length)

getDimNames

public final java.lang.String[] getDimNames()

Returns the array of strings that represent the dimension names. Returns null if there is no dimension name.

Some datasets have pre-defined names for each dimension such as "Latitude" and "Longitude". getDimNames() returns these pre-defined names.

Returns:

the names of dimensions, or null if there is no dimension name.

isString

public boolean isString(int tid)

Checks if a given datatype is a string. Sub-classes must replace this default implementation.

Parameters:

tid - The data type identifier.

Returns:

true if the datatype is a string; otherwise returns false.

getSize

public int getSize(int tid)

Returns the size in bytes of a given datatype. Sub-classes must replace this default implementation.

Parameters:

tid - The data type identifier.

Returns:

The size of the datatype

isEnumConverted

public boolean isEnumConverted()

Get flag that indicate if enum data is converted to strings.

Returns:

the enumConverted

setEnumConverted

public void setEnumConverted(boolean b)

Set flag that indicate if enum data is converted to strings.

Parameters:

b - the enumConverted to set