oracle.dmt.odm
Class PriorProbabilities
java.lang.Object
|
+--oracle.dmt.odm.MiningObject
|
+--oracle.dmt.odm.PriorProbabilities
- All Implemented Interfaces:
- java.io.Serializable
- public class PriorProbabilities
- extends MiningObject
An instance of PriorProbabilities
contains prior probabilities
corresponding to target values. Priors are an optional input for building classification
models. A prior probability is assigned to each target class and used to
overcome a known bias in the sampling procedure that was used to collect the
data presented to the model.
For example, consider two target classes,
responders and non-responders. Suppose that responders make up only
1% of population. For reasons of cost, convenience, or because of the rarity
of the responders, the data might be collected such that it consists of 50%
responders and 50% non-responders, thereby over-sampling the responder
population. To correct this condition, the user may specify prior probabilities
for each class when no known sampling bias exists, the user may
specify the priors as NULL, indicating to the algorithm that the priors are
to be constructed internally from the training table data.
- Since:
- 9.2.0
- See Also:
- Serialized Form
Type | Method |
void |
addEntry(Category target,
float probability)
Adds a new prior probability for the target value. |
float |
getValue(Category target)
Returns the prior probability value associated with the given target Category. |
Category[] |
listTargetValues()
Lists all target Categories present in the PriorProbabilities instance. |
void |
validate()
Validates the set of priors entries to ensure all probability values are between 0 and 1
and the total of all values is less than or equal to 1. |
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
PriorProbabilities
public PriorProbabilities()
- Creates an empty
PriorProbabilities
instance.
addEntry
public void addEntry(Category target,
float probability)
throws ODMException
- Adds a new prior probability for the target value.
- Parameters:
target
- target Category
probability
- prior probability value of the given target- Throws:
ODMException
- target is null
- probability < 0 or probability > 1
- All targets do not have the same data type
- A duplicated entry is being added
- sum of all probabilities > 1
getValue
public float getValue(Category target)
throws ODMException
- Returns the prior probability value associated with the given target Category.
- Parameters:
target
- target Category- Returns:
- prior probability value of the given target
- Throws:
ODMException
- no entry was found in the prior of the given target
validate
public void validate()
throws ODMException
- Validates the set of priors entries to ensure all probability values are between 0 and 1
and the total of all values is less than or equal to 1.
- Throws:
ODMException
- prior probability value is null
- prior probability value < 0 or prior probability value > 1
- sum of all prior probability values > 1
listTargetValues
public Category[] listTargetValues()
- Lists all target Categories present in the
PriorProbabilities
instance.
- Returns:
- an array of target
Category
in the prior