public class RuleStats extends java.lang.Object implements java.io.Serializable, RevisionHandler
Obviously the statistics functions listed above need the specific data and the specific ruleset, which are given in order to instantiate an object of this class.
Constructor and Description |
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RuleStats()
Default constructor
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RuleStats(Instances data,
FastVector rules)
Constructor that provides ruleset and data
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Modifier and Type | Method and Description |
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void |
addAndUpdate(Rule lastRule)
Add a rule to the ruleset and update the stats
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void |
cleanUp()
Frees up memory after classifier has been built.
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double |
combinedDL(double expFPRate,
double predicted)
Compute the combined DL of the ruleset in this class, i.e.
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void |
countData()
Filter the data according to the ruleset and compute the basic
stats: coverage/uncoverage, true/false positive/negatives of
each rule
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void |
countData(int index,
Instances uncovered,
double[][] prevRuleStats)
Count data from the position index in the ruleset
assuming that given data are not covered by the rules
in position 0...(index-1), and the statistics of these
rules are provided.
This procedure is typically useful when a temporary object of RuleStats is constructed in order to efficiently calculate the relative DL of rule in position index, thus all other stuff is not needed. |
static double |
dataDL(double expFPOverErr,
double cover,
double uncover,
double fp,
double fn)
The description length of data given the parameters of the data
based on the ruleset.
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Instances |
getData()
Get the data of the stats
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double[] |
getDistributions(int index)
Get the class distribution predicted by the rule in
given position
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Instances[] |
getFiltered(int index)
Get the data after filtering the given rule
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java.lang.String |
getRevision()
Returns the revision string.
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FastVector |
getRuleset()
Get the ruleset of the stats
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int |
getRulesetSize()
Get the size of the ruleset in the stats
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double[] |
getSimpleStats(int index)
Get the simple stats of one rule, including 6 parameters:
0: coverage; 1:uncoverage; 2: true positive; 3: true negatives;
4: false positives; 5: false negatives
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double |
minDataDLIfDeleted(int index,
double expFPRate,
boolean checkErr)
Compute the minimal data description length of the ruleset
if the rule in the given position is deleted.
The min_data_DL_if_deleted = data_DL_if_deleted - potential |
double |
minDataDLIfExists(int index,
double expFPRate,
boolean checkErr)
Compute the minimal data description length of the ruleset
if the rule in the given position is NOT deleted.
The min_data_DL_if_n_deleted = data_DL_if_n_deleted - potential |
static double |
numAllConditions(Instances data)
Compute the number of all possible conditions that could
appear in a rule of a given data.
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static Instances[] |
partition(Instances data,
int numFolds)
Patition the data into 2, first of which has (numFolds-1)/numFolds of
the data and the second has 1/numFolds of the data
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double |
potential(int index,
double expFPOverErr,
double[] rulesetStat,
double[] ruleStat,
boolean checkErr)
Calculate the potential to decrease DL of the ruleset,
i.e.
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void |
reduceDL(double expFPRate,
boolean checkErr)
Try to reduce the DL of the ruleset by testing removing the rules
one by one in reverse order and update all the stats
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double |
relativeDL(int index,
double expFPRate,
boolean checkErr)
The description length (DL) of the ruleset relative to if the
rule in the given position is deleted, which is obtained by:
MDL if the rule exists - MDL if the rule does not exist Note the minimal possible DL of the ruleset is calculated(i.e. |
void |
removeLast()
Remove the last rule in the ruleset as well as it's stats.
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static Instances |
rmCoveredBySuccessives(Instances data,
FastVector rules,
int index)
Static utility function to count the data covered by the
rules after the given index in the given rules, and then
remove them.
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void |
setData(Instances data)
Set the data of the stats, overwriting the old one if any
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void |
setMDLTheoryWeight(double weight)
Set the weight of theory in MDL calcualtion
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void |
setNumAllConds(double total)
Set the number of all conditions that could appear
in a rule in this RuleStats object, if the number set
is smaller than 0 (typically -1), then it calcualtes
based on the data store
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void |
setRuleset(FastVector rules)
Set the ruleset of the stats, overwriting the old one if any
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static Instances |
stratify(Instances data,
int folds,
java.util.Random rand)
Stratify the given data into the given number of bags based on the class
values.
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static double |
subsetDL(double t,
double k,
double p)
Subset description length:
S(t,k,p) = -k*log2(p)-(n-k)log2(1-p) Details see Quilan: "MDL and categorical theories (Continued)",ML95 |
double |
theoryDL(int index)
The description length of the theory for a given rule.
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public RuleStats()
public RuleStats(Instances data, FastVector rules)
data
- the datarules
- the rulesetpublic void cleanUp()
public void setNumAllConds(double total)
total
- the set numberpublic void setData(Instances data)
data
- the data to be setpublic Instances getData()
public void setRuleset(FastVector rules)
rules
- the set of rules to be setpublic FastVector getRuleset()
public int getRulesetSize()
public double[] getSimpleStats(int index)
index
- the index of the rulepublic Instances[] getFiltered(int index)
index
- the index of the rulepublic double[] getDistributions(int index)
index
- the position index of the rulepublic void setMDLTheoryWeight(double weight)
weight
- the weight to be setpublic static double numAllConditions(Instances data)
data
- the given datapublic void countData()
public void countData(int index, Instances uncovered, double[][] prevRuleStats)
index
- the given positionuncovered
- the data not covered by rules before indexprevRuleStats
- the provided stats of previous rulespublic void addAndUpdate(Rule lastRule)
lastRule
- the rule to be addedpublic static double subsetDL(double t, double k, double p)
t
- the number of elements in a known setk
- the number of elements in a subsetp
- the expected proportion of subset known by recipientpublic double theoryDL(int index)
Details see Quilan: "MDL and categorical theories (Continued)",ML95
index
- the index of the given rule (assuming correct)public static double dataDL(double expFPOverErr, double cover, double uncover, double fp, double fn)
Details see Quinlan: "MDL and categorical theories (Continued)",ML95
expFPOverErr
- expected FP/(FP+FN)cover
- coverageuncover
- uncoveragefp
- False Positivefn
- False Negativepublic double potential(int index, double expFPOverErr, double[] rulesetStat, double[] ruleStat, boolean checkErr)
The way this procedure does is copied from original RIPPER implementation and is quite bizzare because it does not update the following rules' stats recursively any more when testing each rule, which means it assumes after deletion no data covered by the following rules (or regards the deleted rule as the last rule). Reasonable assumption?
index
- the index of the rule in m_Ruleset to be deletedexpFPOverErr
- expected FP/(FP+FN)rulesetStat
- the simple statistics of the ruleset, updated
if the rule should be deletedruleStat
- the simple statistics of the rule to be deletedcheckErr
- whether check if error rate >= 0.5public double minDataDLIfDeleted(int index, double expFPRate, boolean checkErr)
index
- the index of the rule in questionexpFPRate
- expected FP/(FP+FN), used in dataDL calculationcheckErr
- whether check if error rate >= 0.5public double minDataDLIfExists(int index, double expFPRate, boolean checkErr)
index
- the index of the rule in questionexpFPRate
- expected FP/(FP+FN), used in dataDL calculationcheckErr
- whether check if error rate >= 0.5public double relativeDL(int index, double expFPRate, boolean checkErr)
index
- the given position of the rule in question
(assuming correct)expFPRate
- expected FP/(FP+FN), used in dataDL calculationcheckErr
- whether check if error rate >= 0.5public void reduceDL(double expFPRate, boolean checkErr)
expFPRate
- expected FP/(FP+FN), used in dataDL calculationcheckErr
- whether check if error rate >= 0.5public void removeLast()
public static Instances rmCoveredBySuccessives(Instances data, FastVector rules, int index)
data
- the data to be processedrules
- the rulesetindex
- the given indexpublic static final Instances stratify(Instances data, int folds, java.util.Random rand)
Instances.stratify(int fold)
that before stratification it sorts the instances according to the
class order in the header file. It assumes no missing values in the class.data
- the given datafolds
- the given number of foldsrand
- the random object used to randomize the instancespublic double combinedDL(double expFPRate, double predicted)
expFPRate
- expected FP/(FP+FN), used in dataDL calculationpredicted
- the default classification if ruleset covers nullpublic static final Instances[] partition(Instances data, int numFolds)
data
- the given datanumFolds
- the given number of foldspublic java.lang.String getRevision()
getRevision
in interface RevisionHandler