org.apache.sis.referencing.operation.transform

Class TransferFunction

Object

TransferFunction

All Implemented Interfaces:

Serializable, Cloneable

public class TransferFunction
extends Object
implements Cloneable, Serializable

The function converting raster sample values to geophysics values. The function is usually linear, but can sometime be logarithmic or exponential. The later occur most often when measuring concentration of something.

Supported transfer function types

Type	Equation
LINEAR	y = scale⋅x + offset
LOGARITHMIC	y = scale⋅logbase(x) + offset
EXPONENTIAL	y = scale⋅basex + offset

Missing values

This Transfer­Function class handles only the continuous part of transfer functions. This class does not handle missing values other than Na­N. For a more complete class with support for non-NaN missing values, see Grid­Sample­Dimension.

Serialization

Serialized instances of this class are not guaranteed to be compatible with future SIS versions. Serialization should be used only for short term storage or RMI between applications running the same SIS version.

Since:

0.5

See Also:

Serialized Form

Defined in the sis-referencing module

Constructor Summary

Constructors

Constructor and Description
TransferFunction() Creates a transfer function initialized to the identity transform.

Method Summary

Modifier and Type	Method and Description
TransferFunction	clone() Returns a clone of this transfer function.
double	getBase() Returns the logarithm or exponent base in the transfer function.
double	getOffset() Returns the offset of the transfer function.
double	getScale() Returns the scale factor of the transfer function.
MathTransform1D	getTransform() Returns the transform from sample values to geophysics values, as specified by the current properties of this Transfer­Function.
TransferFunctionType	getType() Returns the transfer function type (linear, logarithmic or exponential).
void	setBase(double base) Sets the logarithm or exponent base in the transfer function.
void	setOffset(double offset) Sets the offset of the transfer function.
void	setScale(double scale) Sets the scale factor of the transfer function.
void	setTransform(MathTransform1D function) Sets the transform from sample values to geophysics values.
void	setType(TransferFunctionType type) Sets the transfer function type.
String	toString() Returns a string representation of this transfer function for debugging purpose.

Methods inherited from class Object

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

Constructor Detail

TransferFunction

public TransferFunction()

Creates a transfer function initialized to the identity transform.

Method Detail

getType

public TransferFunctionType getType()

Returns the transfer function type (linear, logarithmic or exponential).

Returns:

the transfer function type.

setType

public void setType(TransferFunctionType type)

Sets the transfer function type. The default value is Transfer­Function­Type.LINEAR.

Parameters:

type - the transfer function type.

getBase

public double getBase()

Returns the logarithm or exponent base in the transfer function. This value is always 1 for Transfer­Function­Type.LINEAR, and usually (but not necessarily) 10 for the logarithmic and exponential types.

Returns:

the logarithmic or exponent base.

setBase

public void setBase(double base)

Sets the logarithm or exponent base in the transfer function. This value is ignored for Transfer­Function­Type.LINEAR. For other supported types, the default value is 10.

Parameters:

base - the new logarithm or exponent base.

getScale

public double getScale()

Returns the scale factor of the transfer function.

Returns:

the scale factor.

setScale

public void setScale(double scale)

Sets the scale factor of the transfer function. The default value is 1.

Parameters:

scale - the new scale factor.

getOffset

public double getOffset()

Returns the offset of the transfer function.

Returns:

the offset.

setOffset

public void setOffset(double offset)

Sets the offset of the transfer function. The default value is 0.

Parameters:

offset - the new offset.

getTransform

public MathTransform1D getTransform()

Returns the transform from sample values to geophysics values, as specified by the current properties of this Transfer­Function.

Returns:

the transform from sample to geophysics values.

setTransform

public void setTransform(MathTransform1D function)
                  throws IllegalArgumentException

Sets the transform from sample values to geophysics values. This method infers the base, scale and offset values from the given transform.

Parameters:

function - the transform to set.

Throws:

Illegal­Argument­Exception - if this method does not recognize the given transform.

clone

public TransferFunction clone()

Returns a clone of this transfer function.

Overrides:

clone in class Object

Returns:

a clone of this transfer function.

Since:

0.8

toString

@Debug
public String toString()

Returns a string representation of this transfer function for debugging purpose. The string returned by this method may change in any future SIS version.

Overrides:

to­String in class Object

Returns:

a string representation of this transfer function.