ucar.multiarray
Interface Accessor

All Known Subinterfaces:

MultiArray, RemoteAccessor

All Known Implementing Classes:

AbstractAccessor

public interface Accessor

Interface for multidimensional array data access. Given an index (array of integers), get or set the value at index.

Netcdf Variables implement this, but more general objects, such as java arrays, can be simply wrapped to provide this interface.

For lack of a better model, we use use naming conventions from java.lang.reflect.Array. In particular, we name the primitive specific "set" functions by type, rather than using overloading. This is symmetric with the "get" operations.

The primitive specific get and set methods are useful only if the the componentType is primitive (like java.lang.Double.TYPE).

Like java.lang.reflect.Array, classes that implement this interface should permit widening conversions to occur during a get or set operation, and throw IllegalArgumentException otherwise. Classes which implement this interface may be more lenient, however, only throwing the exception for narrowing conversions if the unconverted value is out of range for the target type. Implementations may throw UnsupportedOperationException, IllegalArgumentException, or ? for conversions to primitive which don't make sense.

The implementations may be file based or remote, so the methods throw java.io.IOException.

See Also:

AbstractAccessor, MultiArray, RemoteAccessor

Method Summary

void	copyin(int[] origin, MultiArray source) Aggregate write access.
MultiArray	copyout(int[] origin, int[] shape) Aggregate read access.
java.lang.Object	get(int[] index) Get (read) the array element at index.
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.
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.
long	getLong(int[] index) Get the array element at index, as a long.
short	getShort(int[] index) Get the array element at index, as a short.
void	set(int[] index, java.lang.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.
java.lang.Object	toArray() Returns a new array containing all of the elements in this MultiArray.
java.lang.Object	toArray(java.lang.Object anArray, int[] origin, int[] shape) Returns an array containing elements of this MultiArray specified by origin and shape, possibly converting the component type.

Method Detail

get

public java.lang.Object get(int[] index)
                     throws java.io.IOException

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().

Parameters:

index - MultiArray index

Returns:

Object value at index

Throws:

NullPointerException - If the argument is null.

java.lang.IllegalArgumentException - If the array length of index is too small

java.lang.ArrayIndexOutOfBoundsException - If an index component argument is negative, or if it is greater than or equal to the corresponding dimension length.

getBoolean

public boolean getBoolean(int[] index)
                   throws java.io.IOException

Get the array element at index, as a boolean.

See Also:

get(int[])

getChar

public char getChar(int[] index)
             throws java.io.IOException

Get the array element at index, as a char.

See Also:

get(int[])

getByte

public byte getByte(int[] index)
             throws java.io.IOException

Get the array element at index, as a byte.

See Also:

get(int[])

getShort

public short getShort(int[] index)
               throws java.io.IOException

Get the array element at index, as a short.

See Also:

get(int[])

getInt

public int getInt(int[] index)
           throws java.io.IOException

Get the array element at index, as an int.

See Also:

get(int[])

getLong

public long getLong(int[] index)
             throws java.io.IOException

Get the array element at index, as a long.

See Also:

get(int[])

getFloat

public float getFloat(int[] index)
               throws java.io.IOException

Get the array element at index, as a float.

See Also:

get(int[])

getDouble

public double getDouble(int[] index)
                 throws java.io.IOException

Get the array element at index, as a double.

See Also:

get(int[])

set

public void set(int[] index,
                java.lang.Object value)
         throws java.io.IOException

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().

Parameters:

index - MultiArray index

value - the new value.

Throws:

NullPointerException - If the index argument is null, or if the array has a primitive component type and the value argument is null

java.lang.IllegalArgumentException - If the array length of index is too small

java.lang.ArrayIndexOutOfBoundsException - If an index component argument is negative, or if it is greater than or equal to the corresponding dimension length.

setBoolean

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

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

See Also:

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

setChar

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

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

See Also:

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

setByte

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

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

See Also:

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

setShort

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

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

See Also:

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

setInt

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

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

See Also:

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

setLong

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

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

See Also:

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

setFloat

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

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

See Also:

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

setDouble

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

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

See Also:

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

copyout

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

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]);

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

copyin

public void copyin(int[] origin,
                   MultiArray source)
            throws java.io.IOException

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]);

Parameters:

origin - int array specifying the starting index.

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

toArray

public java.lang.Object toArray()
                         throws java.io.IOException

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);
 

Returns:

a one dimensional Array containing all the elements in this MultiArray

toArray

public java.lang.Object toArray(java.lang.Object anArray,
                                int[] origin,
                                int[] shape)
                         throws java.io.IOException

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

Returns:

a one dimensional Array containing the specified elements