uk.ac.starlink.array
Class ConvertArrayImpl

java.lang.Object
  extended by uk.ac.starlink.array.WrapperArrayImpl
      extended by uk.ac.starlink.array.ConvertArrayImpl
All Implemented Interfaces:
ArrayImpl

public class ConvertArrayImpl
extends WrapperArrayImpl

Wraps an NDArray to produce a virtual NDArray whose pixels are modified using a Converter object. Amongst other possibilities this can perform type conversion and transform pixel values using a supplied real function.

Author:
Mark Taylor (Starlink)
See Also:
Converter, TypeConverter

Constructor Summary
ConvertArrayImpl(NDArray nda, Converter conv)
          Constructs a new ArrayImpl from an underlying NDArray and a supplied converter object.
 
Method Summary
 AccessImpl getAccess()
          Returns an object which can access the pixels of this ArrayImpl.
 Number getBadValue()
          The magic bad value for data.
 Type getType()
          Returns the primitive type of the data held by this object.
 
Methods inherited from class uk.ac.starlink.array.WrapperArrayImpl
canMap, close, getMapped, getShape, getWrapped, isRandom, isReadable, isWritable, multipleAccess, open, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

ConvertArrayImpl

public ConvertArrayImpl(NDArray nda,
                        Converter conv)
Constructs a new ArrayImpl from an underlying NDArray and a supplied converter object.

Parameters:
nda - the base NDArray which supplies the pixels to be converted
conv - a Converter object which operates on the pixels of nda. Its base type (type1) must match the type of nda.
Throws:
IllegalArgumentException - if conv.getType1() is not equal to nda.getType().
Method Detail

getType

public Type getType()
Description copied from interface: ArrayImpl
Returns the primitive type of the data held by this object. The return value must not change over the lifetime of the object.

Specified by:
getType in interface ArrayImpl
Overrides:
getType in class WrapperArrayImpl
Returns:
an object representing the type of data held.

getBadValue

public Number getBadValue()
Description copied from interface: ArrayImpl
The magic bad value for data. The returned type should be one of the primitive wrapper types, Byte, Short, Integer, Float, Double as appropriate for the type of this array. It may be null if there is no bad value. The return value must not change over the lifetime of the object.

Specified by:
getBadValue in interface ArrayImpl
Overrides:
getBadValue in class WrapperArrayImpl
Returns:
the bad value

getAccess

public AccessImpl getAccess()
                     throws IOException
Description copied from interface: ArrayImpl
Returns an object which can access the pixels of this ArrayImpl. Each call to this method returns a new and independent AccessImpl, with an offset initialised to 0 (the start of the array data).

This method will only be called after the sole call to open and before the sole call to close.

This method will only be called more than once if the multipleAccess method returns true.

It is the responsibility of the caller to close the returned AccessImpl when it is no longer required; this enables resources it may hold to be released.

Specified by:
getAccess in interface ArrayImpl
Overrides:
getAccess in class WrapperArrayImpl
Returns:
an accessor for the pixel data
Throws:
IOException - if there is an IO error


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