public class Instances
extends java.lang.Object
implements java.io.Serializable
Typical usage (code from the main() method of this class):
...
// Read all the instances in the file
reader = new FileReader(filename);
instances = new Instances(reader);
// Make the last attribute be the class
instances.setClassIndex(instances.numAttributes() - 1);
// Print header and instances.
System.out.println("\nDataset:\n");
System.out.println(instances);
...
All methods that change a set of instances are safe, ie. a change of a set of instances does not affect any other sets of instances. All methods that change a datasets's attribute information clone the dataset before it is changed.
Modifier and Type | Field and Description |
---|---|
static java.lang.String |
FILE_EXTENSION
The filename extension that should be used for arff files
|
protected FastVector |
m_Attributes
The attribute information.
|
protected int |
m_ClassIndex
The class attribute's index
|
protected int[] |
m_IndicesBuffer
Buffer of indices for sparse instance
|
protected FastVector |
m_Instances
The instances.
|
java.lang.String |
m_RelationName
The dataset's name.
|
protected double[] |
m_ValueBuffer
Buffer of values for sparse instance
|
static java.lang.String |
SERIALIZED_OBJ_FILE_EXTENSION
The filename extension that should be used for bin. serialized instances
files
|
Constructor and Description |
---|
Instances(Instances dataset)
Constructor copying all instances and references to the header
information from the given set of instances.
|
Instances(Instances dataset,
int capacity)
Constructor creating an empty set of instances.
|
Instances(Instances source,
int first,
int toCopy)
Creates a new set of instances by copying a subset of another set.
|
Instances(java.io.Reader reader)
Reads an ARFF file from a reader, and assigns a weight of one to each
instance.
|
Instances(java.io.Reader reader,
int capacity)
Reads the header of an ARFF file from a reader and reserves space for the
given number of instances.
|
Instances(java.lang.String relation,
FastVector instances,
FastVector attributes,
int classIndex) |
Instances(java.lang.String name,
FastVector attInfo,
int capacity)
Creates an empty set of instances.
|
Instances(java.util.Vector<Instance> datasets) |
Modifier and Type | Method and Description |
---|---|
void |
add(Instance instance)
Adds one instance to the end of the set.
|
Attribute |
attribute(int index)
Returns an attribute.
|
Attribute |
attribute(java.lang.String name)
Returns an attribute given its name.
|
AttributeStats |
attributeStats(int index)
Calculates summary statistics on the values that appear in this set of
instances for a specified attribute.
|
double[] |
attributeToDoubleArray(int index)
Gets the value of all instances in this dataset for a particular
attribute.
|
boolean |
checkForStringAttributes()
Checks for string attributes in the dataset
|
boolean |
checkInstance(Instance instance)
Checks if the given instance is compatible with this dataset.
|
Attribute |
classAttribute()
Returns the class attribute.
|
int |
classIndex()
Returns the class attribute's index.
|
void |
compactify()
Compactifies the set of instances.
|
protected void |
copyInstances(int from,
Instances dest,
int num)
Copies instances from one set to the end of another one.
|
void |
delete()
Removes all instances from the set.
|
void |
delete(int index)
Removes an instance at the given position from the set.
|
void |
deleteAttributeAt(int position)
Deletes an attribute at the given position (0 to numAttributes() - 1).
|
void |
deleteStringAttributes()
Deletes all string attributes in the dataset.
|
void |
deleteWithMissing(Attribute att)
Removes all instances with missing values for a particular attribute from
the dataset.
|
void |
deleteWithMissing(int attIndex)
Removes all instances with missing values for a particular attribute from
the dataset.
|
void |
deleteWithMissingClass()
Removes all instances with a missing class value from the dataset.
|
java.util.Enumeration |
enumerateAttributes()
Returns an enumeration of all the attributes.
|
java.util.Enumeration |
enumerateInstances()
Returns an enumeration of all instances in the dataset.
|
boolean |
equalHeaders(Instances dataset)
Checks if two headers are equivalent.
|
protected void |
errms(java.io.StreamTokenizer tokenizer,
java.lang.String theMsg)
Throws error message with line number and last token read.
|
Instance |
firstInstance()
Returns the first instance in the set.
|
protected void |
freshAttributeInfo()
Replaces the attribute information by a clone of itself.
|
FastVector |
getAtributtes() |
protected void |
getFirstToken(java.io.StreamTokenizer tokenizer)
Gets next token, skipping empty lines.
|
protected void |
getIndex(java.io.StreamTokenizer tokenizer)
Gets index, checking for a premature and of line.
|
protected boolean |
getInstance(java.io.StreamTokenizer tokenizer,
boolean flag)
Reads a single instance using the tokenizer and appends it to the
dataset.
|
protected boolean |
getInstanceFull(java.io.StreamTokenizer tokenizer,
boolean flag)
Reads a single instance using the tokenizer and appends it to the
dataset.
|
protected boolean |
getInstanceSparse(java.io.StreamTokenizer tokenizer,
boolean flag)
Reads a single instance using the tokenizer and appends it to the
dataset.
|
protected void |
getLastToken(java.io.StreamTokenizer tokenizer,
boolean endOfFileOk)
Gets token and checks if its end of line.
|
protected void |
getNextToken(java.io.StreamTokenizer tokenizer)
Gets next token, checking for a premature and of line.
|
java.util.Random |
getRandomNumberGenerator(long seed)
Returns a random number generator.
|
protected void |
initTokenizer(java.io.StreamTokenizer tokenizer)
Initializes the StreamTokenizer used for reading the ARFF file.
|
void |
insertAttributeAt(Attribute att,
int position)
Inserts an attribute at the given position (0 to numAttributes()) and
sets all values to be missing.
|
Instance |
instance(int index)
Returns the instance at the given position.
|
protected java.lang.String |
instancesAndWeights()
Returns string including all instances, their weights and their indices
in the original dataset.
|
double |
kthSmallestValue(Attribute att,
int k)
Returns the kth-smallest attribute value of a numeric attribute.
|
double |
kthSmallestValue(int attIndex,
int k)
Returns the kth-smallest attribute value of a numeric attribute.
|
Instance |
lastInstance()
Returns the last instance in the set.
|
double |
meanOrMode(Attribute att)
Returns the mean (mode) for a numeric (nominal) attribute as a
floating-point value.
|
double |
meanOrMode(int attIndex)
Returns the mean (mode) for a numeric (nominal) attribute as a
floating-point value.
|
static Instances |
mergeInstances(Instances first,
Instances second)
Merges two sets of Instances together.
|
int |
numAttributes()
Returns the number of attributes.
|
int |
numClasses()
Returns the number of class labels.
|
int |
numDistinctValues(Attribute att)
Returns the number of distinct values of a given attribute.
|
int |
numDistinctValues(int attIndex)
Returns the number of distinct values of a given attribute.
|
int |
numInstances()
Returns the number of instances in the dataset.
|
protected void |
parseAttribute(java.io.StreamTokenizer tokenizer)
Parses the attribute declaration.
|
protected int |
partition(int attIndex,
int l,
int r)
Partitions the instances around a pivot.
|
protected void |
quickSort(int attIndex,
int left,
int right)
Implements quicksort according to Manber's "Introduction to Algorithms".
|
void |
randomize(java.util.Random random)
Shuffles the instances in the set so that they are ordered randomly.
|
protected void |
readHeader(java.io.StreamTokenizer tokenizer)
Reads and stores header of an ARFF file.
|
boolean |
readInstance(java.io.Reader reader)
Reads a single instance from the reader and appends it to the dataset.
|
protected void |
readTillEOL(java.io.StreamTokenizer tokenizer)
Reads and skips all tokens before next end of line token.
|
java.lang.String |
relationName()
Returns the relation's name.
|
void |
renameAttribute(Attribute att,
java.lang.String name)
Renames an attribute.
|
void |
renameAttribute(int att,
java.lang.String name)
Renames an attribute.
|
void |
renameAttributeValue(Attribute att,
java.lang.String val,
java.lang.String name)
Renames the value of a nominal (or string) attribute value.
|
void |
renameAttributeValue(int att,
int val,
java.lang.String name)
Renames the value of a nominal (or string) attribute value.
|
Instances |
resample(java.util.Random random)
Creates a new dataset of the same size using random sampling with
replacement.
|
Instances |
resampleWithWeights(java.util.Random random)
Creates a new dataset of the same size using random sampling with
replacement according to the current instance weights.
|
Instances |
resampleWithWeights(java.util.Random random,
double[] weights)
Creates a new dataset of the same size using random sampling with
replacement according to the given weight vector.
|
protected int |
select(int attIndex,
int left,
int right,
int k)
Implements computation of the kth-smallest element according to Manber's
"Introduction to Algorithms".
|
void |
setClass(Attribute att)
Sets the class attribute.
|
void |
setClassIndex(int classIndex)
Sets the class index of the set.
|
void |
setRelationName(java.lang.String newName)
Sets the relation's name.
|
void |
sort(Attribute att)
Sorts the instances based on an attribute.
|
void |
sort(int attIndex)
Sorts the instances based on an attribute.
|
void |
stratify(int numFolds)
Stratifies a set of instances according to its class values if the class
attribute is nominal (so that afterwards a stratified cross-validation
can be performed).
|
protected void |
stratStep(int numFolds)
Help function needed for stratification of set.
|
Instances |
stringFreeStructure()
Create a copy of the structure, but "cleanse" string types (i.e. doesn't
contain references to the strings seen in the past).
|
protected java.lang.String |
stringWithoutHeader()
Returns the instances in the dataset as a string in ARFF format.
|
double |
sumOfWeights()
Computes the sum of all the instances' weights.
|
void |
swap(int i,
int j)
Swaps two instances in the set.
|
static void |
test(java.lang.String[] argv)
Method for testing this class.
|
Instances |
testCV(int numFolds,
int numFold)
Creates the test set for one fold of a cross-validation on the dataset.
|
java.lang.String |
toString()
Returns the dataset as a string in ARFF format.
|
java.lang.String |
toSummaryString()
Generates a string summarizing the set of instances.
|
Instances |
trainCV(int numFolds,
int numFold)
Creates the training set for one fold of a cross-validation on the
dataset.
|
Instances |
trainCV(int numFolds,
int numFold,
java.util.Random random)
Creates the training set for one fold of a cross-validation on the
dataset.
|
double |
variance(Attribute att)
Computes the variance for a numeric attribute.
|
double |
variance(int attIndex)
Computes the variance for a numeric attribute.
|
public static java.lang.String FILE_EXTENSION
public static java.lang.String SERIALIZED_OBJ_FILE_EXTENSION
public java.lang.String m_RelationName
protected FastVector m_Attributes
protected FastVector m_Instances
protected int m_ClassIndex
protected double[] m_ValueBuffer
protected int[] m_IndicesBuffer
public Instances(java.io.Reader reader) throws java.io.IOException
reader
- the readerjava.io.IOException
- if the ARFF file is not read successfullypublic Instances(java.util.Vector<Instance> datasets)
public Instances(java.io.Reader reader, int capacity) throws java.io.IOException
reader
- the readercapacity
- the capacityjava.lang.IllegalArgumentException
- if the header is not read successfully or the capacity is
negative.java.io.IOException
- if there is a problem with the reader.public Instances(Instances dataset)
dataset
- the set to be copiedpublic Instances(Instances dataset, int capacity)
dataset
- the instances from which the header information is to be takencapacity
- the capacity of the new datasetpublic Instances(java.lang.String relation, FastVector instances, FastVector attributes, int classIndex)
public Instances(Instances source, int first, int toCopy)
source
- the set of instances from which a subset is to be createdfirst
- the index of the first instance to be copiedtoCopy
- the number of instances to be copiedjava.lang.IllegalArgumentException
- if first and toCopy are out of rangepublic Instances(java.lang.String name, FastVector attInfo, int capacity)
name
- the name of the relationattInfo
- the attribute informationcapacity
- the capacity of the setpublic Instances stringFreeStructure()
public FastVector getAtributtes()
public void add(Instance instance)
instance
- the instance to be addedpublic Attribute attribute(int index)
index
- the attribute's indexpublic Attribute attribute(java.lang.String name)
name
- the attribute's namepublic boolean checkForStringAttributes()
public boolean checkInstance(Instance instance)
public Attribute classAttribute()
UnassignedClassException
- if the class is not setpublic int classIndex()
public void compactify()
public void delete()
public void delete(int index)
index
- the instance's positionpublic void deleteAttributeAt(int position)
position
- the attribute's positionjava.lang.IllegalArgumentException
- if the given index is out of range or the class attribute
is being deletedpublic void deleteStringAttributes()
java.lang.IllegalArgumentException
- if string attribute couldn't be successfully deleted
(probably because it is the class attribute).public void deleteWithMissing(int attIndex)
attIndex
- the attribute's indexpublic void deleteWithMissing(Attribute att)
att
- the attributepublic void deleteWithMissingClass()
UnassignedClassException
- if class is not setpublic java.util.Enumeration enumerateAttributes()
public java.util.Enumeration enumerateInstances()
public boolean equalHeaders(Instances dataset)
dataset
- another datasetpublic Instance firstInstance()
public java.util.Random getRandomNumberGenerator(long seed)
seed
- the given seedpublic void insertAttributeAt(Attribute att, int position)
att
- the attribute to be insertedposition
- the attribute's positionjava.lang.IllegalArgumentException
- if the given index is out of rangepublic Instance instance(int index)
index
- the instance's indexpublic double kthSmallestValue(Attribute att, int k)
att
- the Attribute objectk
- the value of kpublic double kthSmallestValue(int attIndex, int k)
attIndex
- the attribute's indexk
- the value of kpublic Instance lastInstance()
public double meanOrMode(int attIndex)
attIndex
- the attribute's indexpublic double meanOrMode(Attribute att)
att
- the attributepublic int numAttributes()
public int numClasses()
UnassignedClassException
- if the class is not setpublic int numDistinctValues(int attIndex)
attIndex
- the attributepublic int numDistinctValues(Attribute att)
att
- the attributepublic int numInstances()
public void randomize(java.util.Random random)
random
- a random number generatorpublic boolean readInstance(java.io.Reader reader) throws java.io.IOException
reader
- the readerjava.io.IOException
- if the information is not read successfullypublic java.lang.String relationName()
public void renameAttribute(int att, java.lang.String name)
att
- the attribute's indexname
- the new namepublic void renameAttribute(Attribute att, java.lang.String name)
att
- the attributename
- the new namepublic void renameAttributeValue(int att, int val, java.lang.String name)
att
- the attribute's indexval
- the value's indexname
- the new namepublic void renameAttributeValue(Attribute att, java.lang.String val, java.lang.String name)
att
- the attributeval
- the valuename
- the new namepublic Instances resample(java.util.Random random)
random
- a random number generatorpublic Instances resampleWithWeights(java.util.Random random)
random
- a random number generatorpublic Instances resampleWithWeights(java.util.Random random, double[] weights)
random
- a random number generatorweights
- the weight vectorjava.lang.IllegalArgumentException
- if the weights array is of the wrong length or contains
negative weights.public void setClass(Attribute att)
att
- attribute to be the classpublic void setClassIndex(int classIndex)
classIndex
- the new class indexjava.lang.IllegalArgumentException
- if the class index is too big or < 0public void setRelationName(java.lang.String newName)
newName
- the new relation name.public void sort(int attIndex)
attIndex
- the attribute's indexpublic void sort(Attribute att)
att
- the attributepublic void stratify(int numFolds)
numFolds
- the number of folds in the cross-validationUnassignedClassException
- if the class is not setpublic double sumOfWeights()
public Instances testCV(int numFolds, int numFold)
numFolds
- the number of folds in the cross-validation. Must be greater
than 1.numFold
- 0 for the first fold, 1 for the second, ...java.lang.IllegalArgumentException
- if the number of folds is less than 2 or greater than the
number of instances.public java.lang.String toString()
toString
in class java.lang.Object
protected java.lang.String stringWithoutHeader()
public Instances trainCV(int numFolds, int numFold)
numFolds
- the number of folds in the cross-validation. Must be greater
than 1.numFold
- 0 for the first fold, 1 for the second, ...java.lang.IllegalArgumentException
- if the number of folds is less than 2 or greater than the
number of instances.public Instances trainCV(int numFolds, int numFold, java.util.Random random)
numFolds
- the number of folds in the cross-validation. Must be greater
than 1.numFold
- 0 for the first fold, 1 for the second, ...random
- the random number generatorjava.lang.IllegalArgumentException
- if the number of folds is less than 2 or greater than the
number of instances.public double variance(int attIndex)
attIndex
- the numeric attributejava.lang.IllegalArgumentException
- if the attribute is not numericpublic double variance(Attribute att)
att
- the numeric attributejava.lang.IllegalArgumentException
- if the attribute is not numericpublic AttributeStats attributeStats(int index)
index
- the index of the attribute to summarize.public double[] attributeToDoubleArray(int index)
index
- the index of the attribute.public java.lang.String toSummaryString()
protected boolean getInstance(java.io.StreamTokenizer tokenizer, boolean flag) throws java.io.IOException
tokenizer
- the tokenizer to be usedflag
- if method should test for carriage return after each instancejava.io.IOException
- if the information is not read successfullyprotected boolean getInstanceSparse(java.io.StreamTokenizer tokenizer, boolean flag) throws java.io.IOException
tokenizer
- the tokenizer to be usedflag
- if method should test for carriage return after each instancejava.io.IOException
- if the information is not read successfullyprotected boolean getInstanceFull(java.io.StreamTokenizer tokenizer, boolean flag) throws java.io.IOException
tokenizer
- the tokenizer to be usedflag
- if method should test for carriage return after each instancejava.io.IOException
- if the information is not read successfullyprotected void readHeader(java.io.StreamTokenizer tokenizer) throws java.io.IOException
tokenizer
- the stream tokenizerjava.io.IOException
- if the information is not read successfullyprotected void parseAttribute(java.io.StreamTokenizer tokenizer) throws java.io.IOException
tokenizer
- the stream tokenizerjava.io.IOException
- if the information is not read successfullyprotected void copyInstances(int from, Instances dest, int num)
source
- the source of the instancesfrom
- the position of the first instance to be copieddest
- the destination for the instancesnum
- the number of instances to be copiedprotected void errms(java.io.StreamTokenizer tokenizer, java.lang.String theMsg) throws java.io.IOException
theMsg
- the error message to be throwntokenizer
- the stream tokenizerIOExcpetion
- containing the error messagejava.io.IOException
protected void freshAttributeInfo()
protected void getFirstToken(java.io.StreamTokenizer tokenizer) throws java.io.IOException
tokenizer
- the stream tokenizerjava.io.IOException
- if reading the next token failsprotected void getIndex(java.io.StreamTokenizer tokenizer) throws java.io.IOException
tokenizer
- the stream tokenizerjava.io.IOException
- if it finds a premature end of lineprotected void getLastToken(java.io.StreamTokenizer tokenizer, boolean endOfFileOk) throws java.io.IOException
tokenizer
- the stream tokenizerjava.io.IOException
- if it doesn't find an end of lineprotected void getNextToken(java.io.StreamTokenizer tokenizer) throws java.io.IOException
tokenizer
- the stream tokenizerjava.io.IOException
- if it finds a premature end of lineprotected void initTokenizer(java.io.StreamTokenizer tokenizer)
tokenizer
- the stream tokenizerprotected java.lang.String instancesAndWeights()
protected int partition(int attIndex, int l, int r)
attIndex
- the attribute's indexleft
- the first index of the subsetright
- the last index of the subsetprotected void quickSort(int attIndex, int left, int right)
attIndex
- the attribute's indexleft
- the first index of the subset to be sortedright
- the last index of the subset to be sortedprotected void readTillEOL(java.io.StreamTokenizer tokenizer) throws java.io.IOException
tokenizer
- the stream tokenizerjava.io.IOException
protected int select(int attIndex, int left, int right, int k)
attIndex
- the attribute's indexleft
- the first index of the subsetright
- the last index of the subsetk
- the value of kprotected void stratStep(int numFolds)
numFolds
- the number of folds for the stratificationpublic void swap(int i, int j)
i
- the first instance's indexj
- the second instance's indexpublic static Instances mergeInstances(Instances first, Instances second)
first
- the first set of Instancessecond
- the second set of Instancesjava.lang.IllegalArgumentException
- if the datasets are not the same sizepublic static void test(java.lang.String[] argv)
argv
- should contain one element: the name of an ARFF file