ucar.netcdf
Class Variable

java.lang.Object
  ucar.netcdf.Variable

All Implemented Interfaces:

Accessor, MultiArray, MultiArrayInfo, Named

public class Variable

extends Object

implements MultiArray, Named

Variable is a (potentially large) multi-dimensional array of primitives. The dimensions are named, allowing relationships between Variables to be expressed. Variables have names and may have descriptive attributes.

Objects which implement this interface exist in the context of a particular Netcdf data set. If you factor out the data access methods of this interface, leaving the descriptive "meta" information, what remains is a ProtoVariable.

Although there is no explicit relationship between this interface and class ProtoVariable, they share common method signatures and semantics where appropriate.

See Also:

ProtoVariable, MultiArray

Field Summary

(package private) Accessor	io
(package private) ProtoVariable	meta

Constructor Summary

Variable(ProtoVariable proto, Accessor io)
The usual constructor.

Method Summary

(package private) void	connectDims(DimensionDictionary dimensions) Ensure that the dimensions referenced by this are members of the specified Dictionary.
void	copyin(int[] origin, MultiArray data) Aggregate write access.
MultiArray	copyout(int[] origin, int[] shape) Aggregate read access.
Object	get(int[] index) Get (read) the array element at index.
Attribute	getAttribute(String name) Convenience function; look up Attribute by name.
AttributeSet	getAttributes() Returns the set of attributes associated with this.
boolean	getBoolean(int[] index) Get the array element at index, as a boolean.
byte	getByte(int[] index) Get the array element at index, as a byte.
char	getChar(int[] index) Get the array element at index, as a char.
Class	getComponentType() Returns the Class object representing the component type of the array.
DimensionIterator	getDimensionIterator() Returns a DimensionIterator of the dimensions used by this variable.
double	getDouble(int[] index) Get the array element at index, as a double.
float	getFloat(int[] index) Get the array element at index, as a float.
int	getInt(int[] index) Get the array element at index, as an int.
int[]	getLengths() Discover the dimensions of this MultiArray.
long	getLong(int[] index) Get the array element at index, as a long.
String	getName() Returns the name of this Variable.
int	getRank() Returns the number of dimensions.
short	getShort(int[] index) Get the array element at index, as a short.
Object	getStorage()
boolean	isScalar() Convenience interface; return true if and only if the rank is zero.
boolean	isUnlimited() Returns true if and only if the this variable can grow.
void	set(int[] index, Object value) Set (modify, write) the array element at index to the specified value.
void	setBoolean(int[] index, boolean value) Set the array element at index to the specified boolean value.
void	setByte(int[] index, byte value) Set the array element at index to the specified byte value.
void	setChar(int[] index, char value) Set the array element at index to the specified char value.
void	setDouble(int[] index, double value) Set the array element at index to the specified double value.
void	setFloat(int[] index, float value) Set the array element at index to the specified float value.
void	setInt(int[] index, int value) Set the array element at index to the specified int value.
void	setLong(int[] index, long value) Set the array element at index to the specified long value.
void	setShort(int[] index, short value) Set the array element at index to the specified short value.
Object	toArray() Returns a new array containing all of the elements in this MultiArray.
Object	toArray(Object dst, int[] origin, int[] shape) Returns an array containing elements of this MultiArray specified by origin and shape, possibly converting the component type.
void	toCdl(StringBuffer buf) Format as CDL.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

meta

final ProtoVariable meta

io

final Accessor io

Constructor Detail

Variable

public Variable(ProtoVariable proto,
                Accessor io)

The usual constructor. Think of it as package private or protected, let AbstactNetcdf call it for you.

Parameters:

proto - the ProtoVariable used as metadata storage. Shouldn't be null. It should be immutable over the lifetime of this object. (If in doubt, hand this its own private copy.)

Method Detail

getComponentType

public Class getComponentType()

Returns the Class object representing the component type of the array.

Specified by:

getComponentType in interface MultiArrayInfo

Returns:

Class of the component type

See Also:

MultiArrayInfo.getComponentType()

getRank

public int getRank()

Returns the number of dimensions.

Specified by:

getRank in interface MultiArrayInfo

Returns:

int number of dimensions

See Also:

MultiArrayInfo.getRank()

getLengths

public int[] getLengths()

Description copied from interface: MultiArrayInfo

Discover the dimensions of this MultiArray.

Specified by:

getLengths in interface MultiArrayInfo

Returns:

int array whose length is the rank of this and whose elements represent the length of each of its dimensions

See Also:

MultiArrayInfo.getLengths()

isUnlimited

public boolean isUnlimited()

Returns true if and only if the this variable can grow. This is equivalent to saying at least one of its dimensions is unlimited. In the current implementation, exactly one dimension, the most slowly varying (leftmost), can be unlimited.

Specified by:

isUnlimited in interface MultiArrayInfo

Returns:

boolean true iff this can grow

isScalar

public boolean isScalar()

Convenience interface; return true if and only if the rank is zero.

Specified by:

isScalar in interface MultiArrayInfo

Returns:

boolean true iff rank == 0

getName

public String getName()

Returns the name of this Variable.

Specified by:

getName in interface Named

Returns:

String which identifies this Variable.

getDimensionIterator

public DimensionIterator getDimensionIterator()

Returns a DimensionIterator of the dimensions used by this variable. The most slowly varying (leftmost for java and C programmers) dimension is first. For scalar variables, the set has no elements and the iteration is empty.

Returns:

DimensionIterator of the elements.

See Also:

DimensionIterator

getAttributes

public AttributeSet getAttributes()

Returns the set of attributes associated with this.

Returns:

AttributeSet. May be empty. Won't be null.

getAttribute

public Attribute getAttribute(String name)

Convenience function; look up Attribute by name.

Parameters:

name - the name of the attribute

Returns:

the attribute, or null if not found

get

public Object get(int[] index)
           throws IOException

Description copied from interface: Accessor

Get (read) the array element at index. The returned value is wrapped in an object if it has a primitive type. Length of index must be greater than or equal to the rank of this. Values of index components must be less than corresponding values from getLengths().

Specified by:

get in interface Accessor

Parameters:

index - MultiArray index

Returns:

Object value at index

Throws:

IOException

getBoolean

public boolean getBoolean(int[] index)
                   throws IOException

Description copied from interface: Accessor

Get the array element at index, as a boolean.

Specified by:

getBoolean in interface Accessor

Throws:

IOException

See Also:

Accessor.get(int[])

getChar

public char getChar(int[] index)
             throws IOException

Description copied from interface: Accessor

Get the array element at index, as a char.

Specified by:

getChar in interface Accessor

Throws:

IOException

See Also:

Accessor.get(int[])

getByte

public byte getByte(int[] index)
             throws IOException

Description copied from interface: Accessor

Get the array element at index, as a byte.

Specified by:

getByte in interface Accessor

Throws:

IOException

See Also:

Accessor.get(int[])

getShort

public short getShort(int[] index)
               throws IOException

Description copied from interface: Accessor

Get the array element at index, as a short.

Specified by:

getShort in interface Accessor

Throws:

IOException

See Also:

Accessor.get(int[])

getInt

public int getInt(int[] index)
           throws IOException

Description copied from interface: Accessor

Get the array element at index, as an int.

Specified by:

getInt in interface Accessor

Throws:

IOException

See Also:

Accessor.get(int[])

getLong

public long getLong(int[] index)
             throws IOException

Description copied from interface: Accessor

Get the array element at index, as a long.

Specified by:

getLong in interface Accessor

Throws:

IOException

See Also:

Accessor.get(int[])

getFloat

public float getFloat(int[] index)
               throws IOException

Description copied from interface: Accessor

Get the array element at index, as a float.

Specified by:

getFloat in interface Accessor

Throws:

IOException

See Also:

Accessor.get(int[])

getDouble

public double getDouble(int[] index)
                 throws IOException

Description copied from interface: Accessor

Get the array element at index, as a double.

Specified by:

getDouble in interface Accessor

Throws:

IOException

See Also:

Accessor.get(int[])

set

public void set(int[] index,
                Object value)
         throws IOException

Description copied from interface: Accessor

Set (modify, write) the array element at index to the specified value. If the array has a primitive component type, the value may be unwrapped. Values of index components must be less than corresponding values from getLengths().

Specified by:

set in interface Accessor

Parameters:

index - MultiArray index

value - the new value.

Throws:

IOException

setBoolean

public void setBoolean(int[] index,
                       boolean value)
                throws IOException

Description copied from interface: Accessor

Set the array element at index to the specified boolean value.

Specified by:

setBoolean in interface Accessor

Throws:

IOException

See Also:

Accessor.set(int[], java.lang.Object)

setChar

public void setChar(int[] index,
                    char value)
             throws IOException

Description copied from interface: Accessor

Set the array element at index to the specified char value.

Specified by:

setChar in interface Accessor

Throws:

IOException

See Also:

Accessor.set(int[], java.lang.Object)

setByte

public void setByte(int[] index,
                    byte value)
             throws IOException

Description copied from interface: Accessor

Set the array element at index to the specified byte value.

Specified by:

setByte in interface Accessor

Throws:

IOException

See Also:

Accessor.set(int[], java.lang.Object)

setShort

public void setShort(int[] index,
                     short value)
              throws IOException

Description copied from interface: Accessor

Set the array element at index to the specified short value.

Specified by:

setShort in interface Accessor

Throws:

IOException

See Also:

Accessor.set(int[], java.lang.Object)

setInt

public void setInt(int[] index,
                   int value)
            throws IOException

Description copied from interface: Accessor

Set the array element at index to the specified int value.

Specified by:

setInt in interface Accessor

Throws:

IOException

See Also:

Accessor.set(int[], java.lang.Object)

setLong

public void setLong(int[] index,
                    long value)
             throws IOException

Description copied from interface: Accessor

Set the array element at index to the specified long value.

Specified by:

setLong in interface Accessor

Throws:

IOException

See Also:

Accessor.set(int[], java.lang.Object)

setFloat

public void setFloat(int[] index,
                     float value)
              throws IOException

Description copied from interface: Accessor

Set the array element at index to the specified float value.

Specified by:

setFloat in interface Accessor

Throws:

IOException

See Also:

Accessor.set(int[], java.lang.Object)

setDouble

public void setDouble(int[] index,
                      double value)
               throws IOException

Description copied from interface: Accessor

Set the array element at index to the specified double value.

Specified by:

setDouble in interface Accessor

Throws:

IOException

See Also:

Accessor.set(int[], java.lang.Object)

copyout

public MultiArray copyout(int[] origin,
                          int[] shape)
                   throws IOException

Description copied from interface: Accessor

Aggregate read access. Return a new MultiArray of the same componentType as this, and with shape as specified, which is initialized to the values of this, as clipped to (origin, origin + shape).

It is easier to implement than to specify :-).

The main reason to implement this instead of using the equivalent proxy is for remote or file access.

assert(origin[ii] + shape[ii] <= lengths[ii]);

Specified by:

copyout in interface Accessor

Parameters:

origin - int array specifying the starting index.

shape - int array specifying the extents in each dimension. This becomes the shape of the return.

Returns:

the MultiArray with the specified shape

Throws:

IOException

copyin

public void copyin(int[] origin,
                   MultiArray data)
            throws IOException

Description copied from interface: Accessor

Aggregate write access. Given a MultiArray, copy it into this at the specified starting index. TODO: clearer specification.

Hopefully this member can be optimized in various situations.

assert(origin[ii] + (source.getLengths())[ii] <= (getLengths())[ii]);

Specified by:

copyin in interface Accessor

Parameters:

origin - int array specifying the starting index.

data - MultiArray with the same componentType as this and shape smaller than this.getLengths() - origin

Throws:

IOException

toArray

public Object toArray()
               throws IOException

Description copied from interface: Accessor

Returns a new array containing all of the elements in this MultiArray. The returned array is one dimensional. The order of the elements in the result is natural, as if we used an IndexIterator to step through the elements of this MultiArray. The component type of the result is the same as this.

This method acts as bridge between array-based and MultiArray-based APIs.

This method is functionally equivalent to

                Object anArray = Array.newInstance(getComponentType(), 1);
                int [] origin = new int[getRank()]
                int [] shape = getDimensions();
                return toArray(anArray, origin, shape);
 

Specified by:

toArray in interface Accessor

Returns:

a one dimensional Array containing all the elements in this MultiArray

Throws:

IOException

getStorage

public Object getStorage()

Specified by:

getStorage in interface MultiArray

Returns:

a the original one dimensional Array containing all the elements in this MultiArray

toArray

public Object toArray(Object dst,
                      int[] origin,
                      int[] shape)
               throws IOException

Description copied from interface: Accessor

Returns an array containing elements of this MultiArray specified by origin and shape, possibly converting the component type. The returned array is one dimensional. The order of the elements in the result is natural, as if we used an IndexIterator to step through the elements of this MultiArray.

The anArray argument should be an array. If it is large enough to contain the output, it is used and no new storage is allocated. Otherwise, new storage is allocated with the same component type as the argument, and the data is copied into it.

This method acts as bridge between array-based and MultiArray-based APIs.

This method is similar to copyout(origin, shape).toArray(), but avoids a copy operation and (potentially) an allocation.

NOTE: Implementation of type conversion is deferred until JDK 1.2. Currently, the componentType of anArray must be the same as this

Specified by:

toArray in interface Accessor

Returns:

a one dimensional Array containing the specified elements

Throws:

IOException

toCdl

public void toCdl(StringBuffer buf)

Format as CDL.

Parameters:

buf - StringBuffer into which to write

toString

public String toString()

Returns:

a CDL string of this.

connectDims

void connectDims(DimensionDictionary dimensions)

Ensure that the dimensions referenced by this are members of the specified Dictionary. This may modify dimArray elements to reference different (equivalent) dimension instances. package private