/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* Instance.java
* Copyright (C) 1999 University of Waikato, Hamilton, New Zealand
*
*/
package weka.core;
import java.io.Serializable;
import java.util.Enumeration;
/**
* Class for handling an instance. All values (numeric, date, nominal, string
* or relational) are internally stored as floating-point numbers. If an
* attribute is nominal (or a string or relational), the stored value is the
* index of the corresponding nominal (or string or relational) value in the
* attribute's definition. We have chosen this approach in favor of a more
* elegant object-oriented approach because it is much faster. <p>
*
* Typical usage (code from the main() method of this class): <p>
*
* <code>
* ... <br>
*
* // Create empty instance with three attribute values <br>
* Instance inst = new Instance(3); <br><br>
*
* // Set instance's values for the attributes "length", "weight", and "position"<br>
* inst.setValue(length, 5.3); <br>
* inst.setValue(weight, 300); <br>
* inst.setValue(position, "first"); <br><br>
*
* // Set instance's dataset to be the dataset "race" <br>
* inst.setDataset(race); <br><br>
*
* // Print the instance <br>
* System.out.println("The instance: " + inst); <br>
*
* ... <br>
* </code><p>
*
* All methods that change an instance are safe, ie. a change of an
* instance does not affect any other instances. All methods that
* change an instance's attribute values clone the attribute value
* vector before it is changed. If your application heavily modifies
* instance values, it may be faster to create a new instance from scratch.
*
* @author Eibe Frank (eibe@cs.waikato.ac.nz)
* @version $Revision: 1.28 $
*/
public class Instance
implements Copyable, Serializable, RevisionHandler {
/** for serialization */
static final long serialVersionUID = 1482635194499365122L;
/** Constant representing a missing value. */
protected static final double MISSING_VALUE = Double.NaN;
/**
* The dataset the instance has access to. Null if the instance
* doesn't have access to any dataset. Only if an instance has
* access to a dataset, it knows about the actual attribute types.
*/
protected /*@spec_public@*/ Instances m_Dataset;
/** The instance's attribute values. */
protected /*@spec_public non_null@*/ double[] m_AttValues;
/** The instance's weight. */
protected double m_Weight;
/**
* Constructor that copies the attribute values and the weight from
* the given instance. Reference to the dataset is set to null.
* (ie. the instance doesn't have access to information about the
* attribute types)
*
* @param instance the instance from which the attribute
* values and the weight are to be copied
*/
//@ ensures m_Dataset == null;
public Instance(/*@non_null@*/ Instance instance) {
m_AttValues = instance.m_AttValues;
m_Weight = instance.m_Weight;
m_Dataset = null;
}
/**
* Constructor that inititalizes instance variable with given
* values. Reference to the dataset is set to null. (ie. the instance
* doesn't have access to information about the attribute types)
*
* @param weight the instance's weight
* @param attValues a vector of attribute values
*/
//@ ensures m_Dataset == null;
public Instance(double weight, /*@non_null@*/ double[]attValues){
m_AttValues = attValues;
m_Weight = weight;
m_Dataset = null;
}
/**
* Constructor of an instance that sets weight to one, all values to
* be missing, and the reference to the dataset to null. (ie. the instance
* doesn't have access to information about the attribute types)
*
* @param numAttributes the size of the instance
*/
//@ requires numAttributes > 0; // Or maybe == 0 is okay too?
//@ ensures m_Dataset == null;
public Instance(int numAttributes) {
m_AttValues = new double[numAttributes];
for (int i = 0; i < m_AttValues.length; i++) {
m_AttValues[i] = MISSING_VALUE;
}
m_Weight = 1;
m_Dataset = null;
}
/**
* Returns the attribute with the given index.
*
* @param index the attribute's index
* @return the attribute at the given position
* @throws UnassignedDatasetException if instance doesn't have access to a
* dataset
*/
//@ requires m_Dataset != null;
public /*@pure@*/ Attribute attribute(int index) {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
return m_Dataset.attribute(index);
}
/**
* Returns the attribute with the given index. Does the same
* thing as attribute().
*
* @param indexOfIndex the index of the attribute's index
* @return the attribute at the given position
* @throws UnassignedDatasetException if instance doesn't have access to a
* dataset
*/
//@ requires m_Dataset != null;
public /*@pure@*/ Attribute attributeSparse(int indexOfIndex) {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
return m_Dataset.attribute(indexOfIndex);
}
/**
* Returns class attribute.
*
* @return the class attribute
* @throws UnassignedDatasetException if the class is not set or the
* instance doesn't have access to a dataset
*/
//@ requires m_Dataset != null;
public /*@pure@*/ Attribute classAttribute() {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
return m_Dataset.classAttribute();
}
/**
* Returns the class attribute's index.
*
* @return the class index as an integer
* @throws UnassignedDatasetException if instance doesn't have access to a dataset
*/
//@ requires m_Dataset != null;
//@ ensures \result == m_Dataset.classIndex();
public /*@pure@*/ int classIndex() {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
return m_Dataset.classIndex();
}
/**
* Tests if an instance's class is missing.
*
* @return true if the instance's class is missing
* @throws UnassignedClassException if the class is not set or the instance doesn't
* have access to a dataset
*/
//@ requires classIndex() >= 0;
public /*@pure@*/ boolean classIsMissing() {
if (classIndex() < 0) {
throw new UnassignedClassException("Class is not set!");
}
return isMissing(classIndex());
}
/**
* Returns an instance's class value in internal format. (ie. as a
* floating-point number)
*
* @return the corresponding value as a double (If the
* corresponding attribute is nominal (or a string) then it returns the
* value's index as a double).
* @throws UnassignedClassException if the class is not set or the instance doesn't
* have access to a dataset
*/
//@ requires classIndex() >= 0;
public /*@pure@*/ double classValue() {
if (classIndex() < 0) {
throw new UnassignedClassException("Class is not set!");
}
return value(classIndex());
}
/**
* Produces a shallow copy of this instance. The copy has
* access to the same dataset. (if you want to make a copy
* that doesn't have access to the dataset, use
* <code>new Instance(instance)</code>
*
* @return the shallow copy
*/
//@ also ensures \result != null;
//@ also ensures \result instanceof Instance;
//@ also ensures ((Instance)\result).m_Dataset == m_Dataset;
public /*@pure@*/ Object copy() {
Instance result = new Instance(this);
result.m_Dataset = m_Dataset;
return result;
}
/**
* Returns the dataset this instance has access to. (ie. obtains
* information about attribute types from) Null if the instance
* doesn't have access to a dataset.
*
* @return the dataset the instance has accesss to
*/
//@ ensures \result == m_Dataset;
public /*@pure@*/ Instances dataset() {
return m_Dataset;
}
/**
* Deletes an attribute at the given position (0 to
* numAttributes() - 1). Only succeeds if the instance does not
* have access to any dataset because otherwise inconsistencies
* could be introduced.
*
* @param position the attribute's position
* @throws RuntimeException if the instance has access to a
* dataset
*/
//@ requires m_Dataset != null;
public void deleteAttributeAt(int position) {
if (m_Dataset != null) {
throw new RuntimeException("Instance has access to a dataset!");
}
forceDeleteAttributeAt(position);
}
/**
* Returns an enumeration of all the attributes.
*
* @return enumeration of all the attributes
* @throws UnassignedDatasetException if the instance doesn't
* have access to a dataset
*/
//@ requires m_Dataset != null;
public /*@pure@*/ Enumeration enumerateAttributes() {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
return m_Dataset.enumerateAttributes();
}
/**
* Tests if the headers of two instances are equivalent.
*
* @param inst another instance
* @return true if the header of the given instance is
* equivalent to this instance's header
* @throws UnassignedDatasetException if instance doesn't have access to any
* dataset
*/
//@ requires m_Dataset != null;
public /*@pure@*/ boolean equalHeaders(Instance inst) {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
return m_Dataset.equalHeaders(inst.m_Dataset);
}
/**
* Tests whether an instance has a missing value. Skips the class attribute if set.
* @return true if instance has a missing value.
* @throws UnassignedDatasetException if instance doesn't have access to any
* dataset
*/
//@ requires m_Dataset != null;
public /*@pure@*/ boolean hasMissingValue() {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
for (int i = 0; i < numAttributes(); i++) {
if (i != classIndex()) {
if (isMissing(i)) {
return true;
}
}
}
return false;
}
/**
* Returns the index of the attribute stored at the given position.
* Just returns the given value.
*
* @param position the position
* @return the index of the attribute stored at the given position
*/
public /*@pure@*/ int index(int position) {
return position;
}
/**
* Inserts an attribute at the given position (0 to
* numAttributes()). Only succeeds if the instance does not
* have access to any dataset because otherwise inconsistencies
* could be introduced.
*
* @param position the attribute's position
* @throws RuntimeException if the instance has accesss to a
* dataset
* @throws IllegalArgumentException if the position is out of range
*/
//@ requires m_Dataset == null;
//@ requires 0 <= position && position <= numAttributes();
public void insertAttributeAt(int position) {
if (m_Dataset != null) {
throw new RuntimeException("Instance has accesss to a dataset!");
}
if ((position < 0) ||
(position > numAttributes())) {
throw new IllegalArgumentException("Can't insert attribute: index out "+
"of range");
}
forceInsertAttributeAt(position);
}
/**
* Tests if a specific value is "missing".
*
* @param attIndex the attribute's index
* @return true if the value is "missing"
*/
public /*@pure@*/ boolean isMissing(int attIndex) {
if (Double.isNaN(m_AttValues[attIndex])) {
return true;
}
return false;
}
/**
* Tests if a specific value is "missing". Does
* the same thing as isMissing() if applied to an Instance.
*
* @param indexOfIndex the index of the attribute's index
* @return true if the value is "missing"
*/
public /*@pure@*/ boolean isMissingSparse(int indexOfIndex) {
if (Double.isNaN(m_AttValues[indexOfIndex])) {
return true;
}
return false;
}
/**
* Tests if a specific value is "missing".
* The given attribute has to belong to a dataset.
*
* @param att the attribute
* @return true if the value is "missing"
*/
public /*@pure@*/ boolean isMissing(Attribute att) {
return isMissing(att.index());
}
/**
* Tests if the given value codes "missing".
*
* @param val the value to be tested
* @return true if val codes "missing"
*/
public static /*@pure@*/ boolean isMissingValue(double val) {
return Double.isNaN(val);
}
/**
* Merges this instance with the given instance and returns
* the result. Dataset is set to null.
*
* @param inst the instance to be merged with this one
* @return the merged instances
*/
public Instance mergeInstance(Instance inst) {
int m = 0;
double [] newVals = new double[numAttributes() + inst.numAttributes()];
for (int j = 0; j < numAttributes(); j++, m++) {
newVals[m] = value(j);
}
for (int j = 0; j < inst.numAttributes(); j++, m++) {
newVals[m] = inst.value(j);
}
return new Instance(1.0, newVals);
}
/**
* Returns the double that codes "missing".
*
* @return the double that codes "missing"
*/
public /*@pure@*/ static double missingValue() {
return MISSING_VALUE;
}
/**
* Returns the number of attributes.
*
* @return the number of attributes as an integer
*/
//@ ensures \result == m_AttValues.length;
public /*@pure@*/ int numAttributes() {
return m_AttValues.length;
}
/**
* Returns the number of class labels.
*
* @return the number of class labels as an integer if the
* class attribute is nominal, 1 otherwise.
* @throws UnassignedDatasetException if instance doesn't have access to any
* dataset
*/
//@ requires m_Dataset != null;
public /*@pure@*/ int numClasses() {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
return m_Dataset.numClasses();
}
/**
* Returns the number of values present. Always the same as numAttributes().
*
* @return the number of values
*/
//@ ensures \result == m_AttValues.length;
public /*@pure@*/ int numValues() {
return m_AttValues.length;
}
/**
* Replaces all missing values in the instance with the
* values contained in the given array. A deep copy of
* the vector of attribute values is performed before the
* values are replaced.
*
* @param array containing the means and modes
* @throws IllegalArgumentException if numbers of attributes are unequal
*/
public void replaceMissingValues(double[] array) {
if ((array == null) ||
(array.length != m_AttValues.length)) {
throw new IllegalArgumentException("Unequal number of attributes!");
}
freshAttributeVector();
for (int i = 0; i < m_AttValues.length; i++) {
if (isMissing(i)) {
m_AttValues[i] = array[i];
}
}
}
/**
* Sets the class value of an instance to be "missing". A deep copy of
* the vector of attribute values is performed before the
* value is set to be missing.
*
* @throws UnassignedClassException if the class is not set
* @throws UnassignedDatasetException if the instance doesn't
* have access to a dataset
*/
//@ requires classIndex() >= 0;
public void setClassMissing() {
if (classIndex() < 0) {
throw new UnassignedClassException("Class is not set!");
}
setMissing(classIndex());
}
/**
* Sets the class value of an instance to the given value (internal
* floating-point format). A deep copy of the vector of attribute
* values is performed before the value is set.
*
* @param value the new attribute value (If the corresponding
* attribute is nominal (or a string) then this is the new value's
* index as a double).
* @throws UnassignedClassException if the class is not set
* @throws UnaddignedDatasetException if the instance doesn't
* have access to a dataset
*/
//@ requires classIndex() >= 0;
public void setClassValue(double value) {
if (classIndex() < 0) {
throw new UnassignedClassException("Class is not set!");
}
setValue(classIndex(), value);
}
/**
* Sets the class value of an instance to the given value. A deep
* copy of the vector of attribute values is performed before the
* value is set.
*
* @param value the new class value (If the class
* is a string attribute and the value can't be found,
* the value is added to the attribute).
* @throws UnassignedClassException if the class is not set
* @throws UnassignedDatasetException if the dataset is not set
* @throws IllegalArgumentException if the attribute is not
* nominal or a string, or the value couldn't be found for a nominal
* attribute
*/
//@ requires classIndex() >= 0;
public final void setClassValue(String value) {
if (classIndex() < 0) {
throw new UnassignedClassException("Class is not set!");
}
setValue(classIndex(), value);
}
/**
* Sets the reference to the dataset. Does not check if the instance
* is compatible with the dataset. Note: the dataset does not know
* about this instance. If the structure of the dataset's header
* gets changed, this instance will not be adjusted automatically.
*
* @param instances the reference to the dataset
*/
public final void setDataset(Instances instances) {
m_Dataset = instances;
}
/**
* Sets a specific value to be "missing". Performs a deep copy
* of the vector of attribute values before the value is set to
* be missing.
*
* @param attIndex the attribute's index
*/
public final void setMissing(int attIndex) {
setValue(attIndex, MISSING_VALUE);
}
/**
* Sets a specific value to be "missing". Performs a deep copy
* of the vector of attribute values before the value is set to
* be missing. The given attribute has to belong to a dataset.
*
* @param att the attribute
*/
public final void setMissing(Attribute att) {
setMissing(att.index());
}
/**
* Sets a specific value in the instance to the given value
* (internal floating-point format). Performs a deep copy
* of the vector of attribute values before the value is set.
*
* @param attIndex the attribute's index
* @param value the new attribute value (If the corresponding
* attribute is nominal (or a string) then this is the new value's
* index as a double).
*/
public void setValue(int attIndex, double value) {
freshAttributeVector();
m_AttValues[attIndex] = value;
}
/**
* Sets a specific value in the instance to the given value
* (internal floating-point format). Performs a deep copy
* of the vector of attribute values before the value is set.
* Does exactly the same thing as setValue().
*
* @param indexOfIndex the index of the attribute's index
* @param value the new attribute value (If the corresponding
* attribute is nominal (or a string) then this is the new value's
* index as a double).
*/
public void setValueSparse(int indexOfIndex, double value) {
freshAttributeVector();
m_AttValues[indexOfIndex] = value;
}
/**
* Sets a value of a nominal or string attribute to the given
* value. Performs a deep copy of the vector of attribute values
* before the value is set.
*
* @param attIndex the attribute's index
* @param value the new attribute value (If the attribute
* is a string attribute and the value can't be found,
* the value is added to the attribute).
* @throws UnassignedDatasetException if the dataset is not set
* @throws IllegalArgumentException if the selected
* attribute is not nominal or a string, or the supplied value couldn't
* be found for a nominal attribute
*/
//@ requires m_Dataset != null;
public final void setValue(int attIndex, String value) {
int valIndex;
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
if (!attribute(attIndex).isNominal() &&
!attribute(attIndex).isString()) {
throw new IllegalArgumentException("Attribute neither nominal nor string!");
}
valIndex = attribute(attIndex).indexOfValue(value);
if (valIndex == -1) {
if (attribute(attIndex).isNominal()) {
throw new IllegalArgumentException("Value not defined for given nominal attribute!");
} else {
attribute(attIndex).forceAddValue(value);
valIndex = attribute(attIndex).indexOfValue(value);
}
}
setValue(attIndex, (double)valIndex);
}
/**
* Sets a specific value in the instance to the given value
* (internal floating-point format). Performs a deep copy of the
* vector of attribute values before the value is set, so if you are
* planning on calling setValue many times it may be faster to
* create a new instance using toDoubleArray. The given attribute
* has to belong to a dataset.
*
* @param att the attribute
* @param value the new attribute value (If the corresponding
* attribute is nominal (or a string) then this is the new value's
* index as a double).
*/
public final void setValue(Attribute att, double value) {
setValue(att.index(), value);
}
/**
* Sets a value of an nominal or string attribute to the given
* value. Performs a deep copy of the vector of attribute values
* before the value is set, so if you are planning on calling setValue many
* times it may be faster to create a new instance using toDoubleArray.
* The given attribute has to belong to a dataset.
*
* @param att the attribute
* @param value the new attribute value (If the attribute
* is a string attribute and the value can't be found,
* the value is added to the attribute).
* @throws IllegalArgumentException if the the attribute is not
* nominal or a string, or the value couldn't be found for a nominal
* attribute
*/
public final void setValue(Attribute att, String value) {
if (!att.isNominal() &&
!att.isString()) {
throw new IllegalArgumentException("Attribute neither nominal nor string!");
}
int valIndex = att.indexOfValue(value);
if (valIndex == -1) {
if (att.isNominal()) {
throw new IllegalArgumentException("Value not defined for given nominal attribute!");
} else {
att.forceAddValue(value);
valIndex = att.indexOfValue(value);
}
}
setValue(att.index(), (double)valIndex);
}
/**
* Modifies the instances value for an attribute (floating point
* representation). Unlike in <code>setValue</code> no deep copy is
* produced, i.e. the actual value is modified.
*
* @param attIndex the attribute's index
* @param value the new attribute value (If the corresponding
* attribute is nominal (or a string) then this is the new value's
* index as a double).
* @author Arne Muller (arne.muller@gmail.com)
*/
public void modifyValue(int attIndex, double value) {
m_AttValues[attIndex] = value;
}
/**
* Sets the weight of an instance.
*
* @param weight the weight
*/
public final void setWeight(double weight) {
m_Weight = weight;
}
/**
* Returns the relational value of a relational attribute.
*
* @param attIndex the attribute's index
* @return the corresponding relation as an Instances object
* @throws IllegalArgumentException if the attribute is not a
* relation-valued attribute
* @throws UnassignedDatasetException if the instance doesn't belong
* to a dataset.
*/
//@ requires m_Dataset != null;
public final /*@pure@*/ Instances relationalValue(int attIndex) {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
return relationalValue(m_Dataset.attribute(attIndex));
}
/**
* Returns the relational value of a relational attribute.
*
* @param att the attribute
* @return the corresponding relation as an Instances object
* @throws IllegalArgumentException if the attribute is not a
* relation-valued attribute
* @throws UnassignedDatasetException if the instance doesn't belong
* to a dataset.
*/
public final /*@pure@*/ Instances relationalValue(Attribute att) {
int attIndex = att.index();
if (att.isRelationValued()) {
return att.relation((int) value(attIndex));
} else {
throw new IllegalArgumentException("Attribute isn't relation-valued!");
}
}
/**
* Returns the value of a nominal, string, date, or relational attribute
* for the instance as a string.
*
* @param attIndex the attribute's index
* @return the value as a string
* @throws IllegalArgumentException if the attribute is not a nominal,
* string, date, or relation-valued attribute.
* @throws UnassignedDatasetException if the instance doesn't belong
* to a dataset.
*/
//@ requires m_Dataset != null;
public final /*@pure@*/ String stringValue(int attIndex) {
if (m_Dataset == null) {
throw new UnassignedDatasetException("Instance doesn't have access to a dataset!");
}
return stringValue(m_Dataset.attribute(attIndex));
}
/**
* Returns the value of a nominal, string, date, or relational attribute
* for the instance as a string.
*
* @param att the attribute
* @return the value as a string
* @throws IllegalArgumentException if the attribute is not a nominal,
* string, date, or relation-valued attribute.
* @throws UnassignedDatasetException if the instance doesn't belong
* to a dataset.
*/
public final /*@pure@*/ String stringValue(Attribute att) {
int attIndex = att.index();
switch (att.type()) {
case Attribute.NOMINAL:
case Attribute.STRING:
return att.value((int) value(attIndex));
case Attribute.DATE:
return att.formatDate(value(attIndex));
case Attribute.RELATIONAL:
return att.relation((int) value(attIndex)).stringWithoutHeader();
default:
throw new IllegalArgumentException("Attribute isn't nominal, string or date!");
}
}
/**
* Returns the values of each attribute as an array of doubles.
*
* @return an array containing all the instance attribute values
*/
public double[] toDoubleArray() {
double[] newValues = new double[m_AttValues.length];
System.arraycopy(m_AttValues, 0, newValues, 0,
m_AttValues.length);
return newValues;
}
/**
* Returns the description of one instance. If the instance
* doesn't have access to a dataset, it returns the internal
* floating-point values. Quotes string
* values that contain whitespace characters.
*
* @return the instance's description as a string
*/
public String toString() {
StringBuffer text = new StringBuffer();
for (int i = 0; i < m_AttValues.length; i++) {
if (i > 0) text.append(",");
text.append(toString(i));
}
if (m_Weight != 1.0) {
text.append(",{" + Utils.doubleToString(m_Weight, 6) + "}");
}
return text.toString();
}
/**
* Returns the description of one value of the instance as a
* string. If the instance doesn't have access to a dataset, it
* returns the internal floating-point value. Quotes string
* values that contain whitespace characters, or if they
* are a question mark.
*
* @param attIndex the attribute's index
* @return the value's description as a string
*/
public final /*@pure@*/ String toString(int attIndex) {
StringBuffer text = new StringBuffer();
if (isMissing(attIndex)) {
text.append("?");
} else {
if (m_Dataset == null) {
text.append(Utils.doubleToString(m_AttValues[attIndex],6));
} else {
switch (m_Dataset.attribute(attIndex).type()) {
case Attribute.NOMINAL:
case Attribute.STRING:
case Attribute.DATE:
case Attribute.RELATIONAL:
text.append(Utils.quote(stringValue(attIndex)));
break;
case Attribute.NUMERIC:
text.append(Utils.doubleToString(value(attIndex),6));
break;
default:
throw new IllegalStateException("Unknown attribute type");
}
}
}
return text.toString();
}
/**
* Returns the description of one value of the instance as a
* string. If the instance doesn't have access to a dataset it
* returns the internal floating-point value. Quotes string
* values that contain whitespace characters, or if they
* are a question mark.
* The given attribute has to belong to a dataset.
*
* @param att the attribute
* @return the value's description as a string
*/
public final String toString(Attribute att) {
return toString(att.index());
}
/**
* Returns an instance's attribute value in internal format.
*
* @param attIndex the attribute's index
* @return the specified value as a double (If the corresponding
* attribute is nominal (or a string) then it returns the value's index as a
* double).
*/
public /*@pure@*/ double value(int attIndex) {
return m_AttValues[attIndex];
}
/**
* Returns an instance's attribute value in internal format.
* Does exactly the same thing as value() if applied to an Instance.
*
* @param indexOfIndex the index of the attribute's index
* @return the specified value as a double (If the corresponding
* attribute is nominal (or a string) then it returns the value's index as a
* double).
*/
public /*@pure@*/ double valueSparse(int indexOfIndex) {
return m_AttValues[indexOfIndex];
}
/**
* Returns an instance's attribute value in internal format.
* The given attribute has to belong to a dataset.
*
* @param att the attribute
* @return the specified value as a double (If the corresponding
* attribute is nominal (or a string) then it returns the value's index as a
* double).
*/
public /*@pure@*/ double value(Attribute att) {
return value(att.index());
}
/**
* Returns the instance's weight.
*
* @return the instance's weight as a double
*/
public final /*@pure@*/ double weight() {
return m_Weight;
}
/**
* Deletes an attribute at the given position (0 to
* numAttributes() - 1).
*
* @param position the attribute's position
*/
void forceDeleteAttributeAt(int position) {
double[] newValues = new double[m_AttValues.length - 1];
System.arraycopy(m_AttValues, 0, newValues, 0, position);
if (position < m_AttValues.length - 1) {
System.arraycopy(m_AttValues, position + 1,
newValues, position,
m_AttValues.length - (position + 1));
}
m_AttValues = newValues;
}
/**
* Inserts an attribute at the given position
* (0 to numAttributes()) and sets its value to be missing.
*
* @param position the attribute's position
*/
void forceInsertAttributeAt(int position) {
double[] newValues = new double[m_AttValues.length + 1];
System.arraycopy(m_AttValues, 0, newValues, 0, position);
newValues[position] = MISSING_VALUE;
System.arraycopy(m_AttValues, position, newValues,
position + 1, m_AttValues.length - position);
m_AttValues = newValues;
}
/**
* Private constructor for subclasses. Does nothing.
*/
protected Instance() {
}
/**
* Clones the attribute vector of the instance and
* overwrites it with the clone.
*/
private void freshAttributeVector() {
m_AttValues = toDoubleArray();
}
/**
* Main method for testing this class.
*
* @param options the commandline options - ignored
*/
//@ requires options != null;
public static void main(String[] options) {
try {
// Create numeric attributes "length" and "weight"
Attribute length = new Attribute("length");
Attribute weight = new Attribute("weight");
// Create vector to hold nominal values "first", "second", "third"
FastVector my_nominal_values = new FastVector(3);
my_nominal_values.addElement("first");
my_nominal_values.addElement("second");
my_nominal_values.addElement("third");
// Create nominal attribute "position"
Attribute position = new Attribute("position", my_nominal_values);
// Create vector of the above attributes
FastVector attributes = new FastVector(3);
attributes.addElement(length);
attributes.addElement(weight);
attributes.addElement(position);
// Create the empty dataset "race" with above attributes
Instances race = new Instances("race", attributes, 0);
// Make position the class attribute
race.setClassIndex(position.index());
// Create empty instance with three attribute values
Instance inst = new Instance(3);
// Set instance's values for the attributes "length", "weight", and "position"
inst.setValue(length, 5.3);
inst.setValue(weight, 300);
inst.setValue(position, "first");
// Set instance's dataset to be the dataset "race"
inst.setDataset(race);
// Print the instance
System.out.println("The instance: " + inst);
// Print the first attribute
System.out.println("First attribute: " + inst.attribute(0));
// Print the class attribute
System.out.println("Class attribute: " + inst.classAttribute());
// Print the class index
System.out.println("Class index: " + inst.classIndex());
// Say if class is missing
System.out.println("Class is missing: " + inst.classIsMissing());
// Print the instance's class value in internal format
System.out.println("Class value (internal format): " + inst.classValue());
// Print a shallow copy of this instance
Instance copy = (Instance) inst.copy();
System.out.println("Shallow copy: " + copy);
// Set dataset for shallow copy
copy.setDataset(inst.dataset());
System.out.println("Shallow copy with dataset set: " + copy);
// Unset dataset for copy, delete first attribute, and insert it again
copy.setDataset(null);
copy.deleteAttributeAt(0);
copy.insertAttributeAt(0);
copy.setDataset(inst.dataset());
System.out.println("Copy with first attribute deleted and inserted: " + copy);
// Enumerate attributes (leaving out the class attribute)
System.out.println("Enumerating attributes (leaving out class):");
Enumeration enu = inst.enumerateAttributes();
while (enu.hasMoreElements()) {
Attribute att = (Attribute) enu.nextElement();
System.out.println(att);
}
// Headers are equivalent?
System.out.println("Header of original and copy equivalent: " +
inst.equalHeaders(copy));
// Test for missing values
System.out.println("Length of copy missing: " + copy.isMissing(length));
System.out.println("Weight of copy missing: " + copy.isMissing(weight.index()));
System.out.println("Length of copy missing: " +
Instance.isMissingValue(copy.value(length)));
System.out.println("Missing value coded as: " + Instance.missingValue());
// Prints number of attributes and classes
System.out.println("Number of attributes: " + copy.numAttributes());
System.out.println("Number of classes: " + copy.numClasses());
// Replace missing values
double[] meansAndModes = {2, 3, 0};
copy.replaceMissingValues(meansAndModes);
System.out.println("Copy with missing value replaced: " + copy);
// Setting and getting values and weights
copy.setClassMissing();
System.out.println("Copy with missing class: " + copy);
copy.setClassValue(0);
System.out.println("Copy with class value set to first value: " + copy);
copy.setClassValue("third");
System.out.println("Copy with class value set to \"third\": " + copy);
copy.setMissing(1);
System.out.println("Copy with second attribute set to be missing: " + copy);
copy.setMissing(length);
System.out.println("Copy with length set to be missing: " + copy);
copy.setValue(0, 0);
System.out.println("Copy with first attribute set to 0: " + copy);
copy.setValue(weight, 1);
System.out.println("Copy with weight attribute set to 1: " + copy);
copy.setValue(position, "second");
System.out.println("Copy with position set to \"second\": " + copy);
copy.setValue(2, "first");
System.out.println("Copy with last attribute set to \"first\": " + copy);
System.out.println("Current weight of instance copy: " + copy.weight());
copy.setWeight(2);
System.out.println("Current weight of instance copy (set to 2): " + copy.weight());
System.out.println("Last value of copy: " + copy.toString(2));
System.out.println("Value of position for copy: " + copy.toString(position));
System.out.println("Last value of copy (internal format): " + copy.value(2));
System.out.println("Value of position for copy (internal format): " +
copy.value(position));
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Returns the revision string.
*
* @return the revision
*/
public String getRevision() {
return RevisionUtils.extract("$Revision: 1.28 $");
}
}