weka.core

Class Capabilities

java.lang.Object

weka.core.Capabilities

All Implemented Interfaces:

Serializable, Cloneable, RevisionHandler

public class Capabilities
extends Object
implements Cloneable, Serializable, RevisionHandler

A class that describes the capabilites (e.g., handling certain types of attributes, missing values, types of classes, etc.) of a specific classifier. By default, the classifier is capable of nothing. This ensures that new features have to be enabled explicitly.

A common code fragment for making use of the capabilities in a classifier would be this:

 public void buildClassifier(Instances instances) throws Exception {
   // can the classifier handle the data?
   getCapabilities().testWithFail(instances);
   ...
   // possible deletion of instances with missing class labels, etc.
 

For only testing a single attribute, use this:

   ...
   Attribute att = instances.attribute(0);
   getCapabilities().testWithFail(att);
   ...
 

Or for testing the class attribute (uses the capabilities that are especially for the class):

   ...
   Attribute att = instances.classAttribute();
   getCapabilities().testWithFail(att, true);
   ...
 

Version:

$Revision: 10203 $

Author:

FracPete (fracpete at waikato dot ac dot nz)

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Capabilities.Capability enumeration of all capabilities

Field Summary

Fields

Modifier and Type	Field and Description
static String	PROPERTIES_FILE the properties file for managing the tests

Constructor Summary

Constructors

Constructor and Description
Capabilities(CapabilitiesHandler owner) initializes the capabilities for the given owner

Method Summary

Methods

Modifier and Type	Method and Description
void	and(Capabilities c) performs an AND conjunction with the capabilities of the given Capabilities object and updates itself
void	assign(Capabilities c) retrieves the data from the given Capabilities object
Iterator<Capabilities.Capability>	capabilities() Returns an Iterator over the stored capabilities
Object	clone() Creates and returns a copy of this object.
Iterator<Capabilities.Capability>	dependencies() Returns an Iterator over the stored dependencies
void	disable(Capabilities.Capability c) disables the given capability Disabling NOMINAL_ATTRIBUTES also disables BINARY_ATTRIBUTES, UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES.
void	disableAll() disables all attribute and class types (including dependencies)
void	disableAllAttributeDependencies() disables all attribute type dependencies
void	disableAllAttributes() disables all attribute types
void	disableAllClassDependencies() disables all class type dependencies
void	disableAllClasses() disables all class types
void	disableDependency(Capabilities.Capability c) disables the dependency of the given capability Disabling NOMINAL_ATTRIBUTES also disables BINARY_ATTRIBUTES, UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES.
void	enable(Capabilities.Capability c) enables the given capability.
void	enableAll() enables all attribute and class types (including dependencies)
void	enableAllAttributeDependencies() enables all attribute type dependencies
void	enableAllAttributes() enables all attribute types
void	enableAllClassDependencies() enables all class type dependencies
void	enableAllClasses() enables all class types
void	enableDependency(Capabilities.Capability c) enables the dependency flag for the given capability Enabling NOMINAL_ATTRIBUTES also enables BINARY_ATTRIBUTES, UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES.
static Capabilities	forInstances(Instances data) returns a Capabilities object specific for this data.
static Capabilities	forInstances(Instances data, boolean multi) returns a Capabilities object specific for this data.
Capabilities	getAttributeCapabilities() returns all attribute capabilities
Capabilities	getClassCapabilities() returns all class capabilities
Exception	getFailReason() returns the reason why the tests failed, is null if tests succeeded
int	getMinimumNumberInstances() returns the minimum number of instances that have to be in the dataset
Capabilities	getOtherCapabilities() returns all other capabilities, besides class and attribute related ones
CapabilitiesHandler	getOwner() returns the owner of this capabilities object
String	getRevision() Returns the revision string.
boolean	handles(Capabilities.Capability c) returns true if the classifier handler has the specified capability
boolean	hasDependencies() Checks whether there are any dependencies at all
boolean	hasDependency(Capabilities.Capability c) returns true if the classifier handler has a dependency for the specified capability
static void	main(String[] args) loads the given dataset and prints the Capabilities necessary to process it.
void	or(Capabilities c) performs an OR conjunction with the capabilities of the given Capabilities object and updates itself
void	setMinimumNumberInstances(int value) sets the minimum number of instances that have to be in the dataset
void	setOwner(CapabilitiesHandler value) sets the owner of this capabilities object
void	setTestWithFailAlwaysSucceeds(boolean flag) Whether test with fail should always succeed.
boolean	supports(Capabilities c) Returns true if the currently set capabilities support at least all of the capabiliites of the given Capabilities object (checks only the enum!)
boolean	supportsMaybe(Capabilities c) Returns true if the currently set capabilities support (or have a dependency) at least all of the capabilities of the given Capabilities object (checks only the enum!)
boolean	test(Attribute att) Test the given attribute, whether it can be processed by the handler, given its capabilities.
boolean	test(Attribute att, boolean isClass) Test the given attribute, whether it can be processed by the handler, given its capabilities.
boolean	test(Instances data) Tests the given data, whether it can be processed by the handler, given its capabilities.
boolean	test(Instances data, int fromIndex, int toIndex) Tests a certain range of attributes of the given data, whether it can be processed by the handler, given its capabilities.
void	testWithFail(Attribute att) tests the given attribute by calling the test(Attribute,boolean) method and throws an exception if the test fails.
void	testWithFail(Attribute att, boolean isClass) tests the given attribute by calling the test(Attribute,boolean) method and throws an exception if the test fails.
void	testWithFail(Instances data) tests the given data by calling the test(Instances) method and throws an exception if the test fails.
void	testWithFail(Instances data, int fromIndex, int toIndex) tests the given data by calling the test(Instances,int,int) method and throws an exception if the test fails.
String	toSource(String objectname) turns the capabilities object into source code.
String	toSource(String objectname, int indent) turns the capabilities object into source code.
String	toString() returns a string representation of the capabilities

Methods inherited from class java.lang.Object

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

Field Detail

PROPERTIES_FILE

public static final String PROPERTIES_FILE

the properties file for managing the tests

See Also:

Constant Field Values

Constructor Detail

Capabilities

public Capabilities(CapabilitiesHandler owner)

initializes the capabilities for the given owner

Parameters:

owner - the object that produced this Capabilities instance

Method Detail

clone

public Object clone()

Creates and returns a copy of this object.

Overrides:

clone in class Object

Returns:

a clone of this object

assign

public void assign(Capabilities c)

retrieves the data from the given Capabilities object

Parameters:

c - the capabilities object to initialize with

and

public void and(Capabilities c)

performs an AND conjunction with the capabilities of the given Capabilities object and updates itself

Parameters:

c - the capabilities to AND with

or

public void or(Capabilities c)

performs an OR conjunction with the capabilities of the given Capabilities object and updates itself

Parameters:

c - the capabilities to OR with

supports

public boolean supports(Capabilities c)

Returns true if the currently set capabilities support at least all of the capabiliites of the given Capabilities object (checks only the enum!)

Parameters:

c - the capabilities to support at least

Returns:

true if all the requested capabilities are supported

supportsMaybe

public boolean supportsMaybe(Capabilities c)

Returns true if the currently set capabilities support (or have a dependency) at least all of the capabilities of the given Capabilities object (checks only the enum!)

Parameters:

c - the capabilities (or dependencies) to support at least

Returns:

true if all the requested capabilities are supported (or at least have a dependency)

setOwner

public void setOwner(CapabilitiesHandler value)

sets the owner of this capabilities object

Parameters:

value - the new owner

getOwner

public CapabilitiesHandler getOwner()

returns the owner of this capabilities object

Returns:

the current owner of this capabilites object

setMinimumNumberInstances

public void setMinimumNumberInstances(int value)

sets the minimum number of instances that have to be in the dataset

Parameters:

value - the minimum number of instances

getMinimumNumberInstances

public int getMinimumNumberInstances()

returns the minimum number of instances that have to be in the dataset

Returns:

the minimum number of instances

capabilities

public Iterator<Capabilities.Capability> capabilities()

Returns an Iterator over the stored capabilities

Returns:

iterator over the current capabilities

dependencies

public Iterator<Capabilities.Capability> dependencies()

Returns an Iterator over the stored dependencies

Returns:

iterator over the current dependencies

enable

public void enable(Capabilities.Capability c)

enables the given capability. Enabling NOMINAL_ATTRIBUTES also enables BINARY_ATTRIBUTES, UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES. Enabling BINARY_ATTRIBUTES also enables UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES. Enabling UNARY_ATTRIBUTES also enables EMPTY_NOMINAL_ATTRIBUTES. But NOMINAL_CLASS only enables BINARY_CLASS, since normal schemes in Weka don't work with datasets that have only 1 class label (or none).

Parameters:

c - the capability to enable

enableDependency

public void enableDependency(Capabilities.Capability c)

enables the dependency flag for the given capability Enabling NOMINAL_ATTRIBUTES also enables BINARY_ATTRIBUTES, UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES. Enabling BINARY_ATTRIBUTES also enables UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES. Enabling UNARY_ATTRIBUTES also enables EMPTY_NOMINAL_ATTRIBUTES. But NOMINAL_CLASS only enables BINARY_CLASS, since normal schemes in Weka don't work with datasets that have only 1 class label (or none).

Parameters:

c - the capability to enable the dependency flag for

enableAllClasses

public void enableAllClasses()

enables all class types

See Also:

disableAllClasses(), getClassCapabilities()

enableAllClassDependencies

public void enableAllClassDependencies()

enables all class type dependencies

See Also:

disableAllClassDependencies(), getClassCapabilities()

enableAllAttributes

public void enableAllAttributes()

enables all attribute types

See Also:

disableAllAttributes(), getAttributeCapabilities()

enableAllAttributeDependencies

public void enableAllAttributeDependencies()

enables all attribute type dependencies

See Also:

disableAllAttributeDependencies(), getAttributeCapabilities()

enableAll

public void enableAll()

enables all attribute and class types (including dependencies)

disable

public void disable(Capabilities.Capability c)

disables the given capability Disabling NOMINAL_ATTRIBUTES also disables BINARY_ATTRIBUTES, UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES. Disabling BINARY_ATTRIBUTES also disables UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES. Disabling UNARY_ATTRIBUTES also disables EMPTY_NOMINAL_ATTRIBUTES. The same hierarchy applies to the class capabilities.

Parameters:

c - the capability to disable

disableDependency

public void disableDependency(Capabilities.Capability c)

disables the dependency of the given capability Disabling NOMINAL_ATTRIBUTES also disables BINARY_ATTRIBUTES, UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES. Disabling BINARY_ATTRIBUTES also disables UNARY_ATTRIBUTES and EMPTY_NOMINAL_ATTRIBUTES. Disabling UNARY_ATTRIBUTES also disables EMPTY_NOMINAL_ATTRIBUTES. The same hierarchy applies to the class capabilities.

Parameters:

c - the capability to disable the dependency flag for

disableAllClasses

public void disableAllClasses()

disables all class types

See Also:

enableAllClasses(), getClassCapabilities()

disableAllClassDependencies

public void disableAllClassDependencies()

disables all class type dependencies

See Also:

enableAllClassDependencies(), getClassCapabilities()

disableAllAttributes

public void disableAllAttributes()

disables all attribute types

See Also:

enableAllAttributes(), getAttributeCapabilities()

disableAllAttributeDependencies

public void disableAllAttributeDependencies()

disables all attribute type dependencies

See Also:

enableAllAttributeDependencies(), getAttributeCapabilities()

disableAll

public void disableAll()

disables all attribute and class types (including dependencies)

getClassCapabilities

public Capabilities getClassCapabilities()

returns all class capabilities

Returns:

all capabilities regarding the class

See Also:

enableAllClasses(), disableAllClasses()

getAttributeCapabilities

public Capabilities getAttributeCapabilities()

returns all attribute capabilities

Returns:

all capabilities regarding attributes

See Also:

enableAllAttributes(), disableAllAttributes()

getOtherCapabilities

public Capabilities getOtherCapabilities()

returns all other capabilities, besides class and attribute related ones

Returns:

all other capabilities, besides class and attribute related ones

handles

public boolean handles(Capabilities.Capability c)

returns true if the classifier handler has the specified capability

Parameters:

c - the capability to test

Returns:

true if the classifier handler has the capability

hasDependency

public boolean hasDependency(Capabilities.Capability c)

returns true if the classifier handler has a dependency for the specified capability

Parameters:

c - the capability to test

Returns:

true if the classifier handler has a dependency for the capability

hasDependencies

public boolean hasDependencies()

Checks whether there are any dependencies at all

Returns:

true if there is at least one dependency for a capability

getFailReason

public Exception getFailReason()

returns the reason why the tests failed, is null if tests succeeded

Returns:

the reason why the tests failed

test

public boolean test(Attribute att)

Test the given attribute, whether it can be processed by the handler, given its capabilities. The method assumes that the specified attribute is not the class attribute.

Parameters:

att - the attribute to test

Returns:

true if all the tests succeeded

See Also:

test(Attribute, boolean)

test

public boolean test(Attribute att,
           boolean isClass)

Test the given attribute, whether it can be processed by the handler, given its capabilities.

Parameters:

att - the attribute to test

isClass - whether this attribute is the class attribute

Returns:

true if all the tests succeeded

See Also:

m_AttributeTest

test

public boolean test(Instances data)

Tests the given data, whether it can be processed by the handler, given its capabilities. Classifiers implementing the MultiInstanceCapabilitiesHandler interface are checked automatically for their multi-instance Capabilities (if no bags, then only the bag-structure, otherwise only the first bag).

Parameters:

data - the data to test

Returns:

true if all the tests succeeded

See Also:

test(Instances, int, int)

test

public boolean test(Instances data,
           int fromIndex,
           int toIndex)

Tests a certain range of attributes of the given data, whether it can be processed by the handler, given its capabilities. Classifiers implementing the MultiInstanceCapabilitiesHandler interface are checked automatically for their multi-instance Capabilities (if no bags, then only the bag-structure, otherwise only the first bag).

Parameters:

data - the data to test

fromIndex - the range of attributes - start (incl.)

toIndex - the range of attributes - end (incl.)

Returns:

true if all the tests succeeded

See Also:

MultiInstanceCapabilitiesHandler, m_InstancesTest, m_MissingValuesTest, m_MissingClassValuesTest, m_MinimumNumberInstancesTest

setTestWithFailAlwaysSucceeds

public void setTestWithFailAlwaysSucceeds(boolean flag)

Whether test with fail should always succeed. This can be used to effectively turn off the test, e.g. in buildClassifier() methods, to avoid the additional runtime required by capabilities testing.

Parameters:

flag - if true, the various testWithFail methods always succeed

testWithFail

public void testWithFail(Attribute att)
                  throws Exception

tests the given attribute by calling the test(Attribute,boolean) method and throws an exception if the test fails. The method assumes that the specified attribute is not the class attribute.

Parameters:

att - the attribute to test

Throws:

Exception - in case the attribute doesn't pass the tests

See Also:

test(Attribute,boolean)

testWithFail

public void testWithFail(Attribute att,
                boolean isClass)
                  throws Exception

tests the given attribute by calling the test(Attribute,boolean) method and throws an exception if the test fails.

Parameters:

att - the attribute to test

isClass - whether this attribute is the class attribute

Throws:

Exception - in case the attribute doesn't pass the tests

See Also:

test(Attribute,boolean)

testWithFail

public void testWithFail(Instances data,
                int fromIndex,
                int toIndex)
                  throws Exception

tests the given data by calling the test(Instances,int,int) method and throws an exception if the test fails.

Parameters:

data - the data to test

fromIndex - the range of attributes - start (incl.)

toIndex - the range of attributes - end (incl.)

Throws:

Exception - in case the data doesn't pass the tests

See Also:

test(Instances,int,int)

testWithFail

public void testWithFail(Instances data)
                  throws Exception

tests the given data by calling the test(Instances) method and throws an exception if the test fails.

Parameters:

data - the data to test

Throws:

Exception - in case the data doesn't pass the tests

See Also:

test(Instances)

toString

public String toString()

returns a string representation of the capabilities

Overrides:

toString in class Object

Returns:

a string representation of this object

toSource

public String toSource(String objectname)

turns the capabilities object into source code. The returned source code is a block that creates a Capabilities object named 'objectname' and enables all the capabilities of this Capabilities object.

Parameters:

objectname - the name of the Capabilities object being instantiated

Returns:

the generated source code

toSource

public String toSource(String objectname,
              int indent)

turns the capabilities object into source code. The returned source code is a block that creates a Capabilities object named 'objectname' and enables all the capabilities of this Capabilities object.

Parameters:

objectname - the name of the Capabilities object being instantiated

indent - the number of blanks to indent

Returns:

the generated source code

forInstances

public static Capabilities forInstances(Instances data)
                                 throws Exception

returns a Capabilities object specific for this data. The multi-instance capability is not checked as well as the minimum number of instances is not set.

Parameters:

data - the data to base the capabilities on

Returns:

a data-specific capabilities object

Throws:

Exception - in case an error occurrs, e.g., an unknown attribute type

forInstances

public static Capabilities forInstances(Instances data,
                        boolean multi)
                                 throws Exception

returns a Capabilities object specific for this data. The minimum number of instances is not set, the check for multi-instance data is optional.

Parameters:

data - the data to base the capabilities on

multi - if true then the structure is checked, too

Returns:

a data-specific capabilities object

Throws:

Exception - in case an error occurrs, e.g., an unknown attribute type

main

public static void main(String[] args)
                 throws Exception

loads the given dataset and prints the Capabilities necessary to process it.

Valid parameters:

-file filename
the file to load -c index the explicit index of the class attribute (default: none)

Parameters:

args - the commandline arguments

Throws:

Exception - if something goes wrong

getRevision

public String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision