def createInputVector(self, instance: Instance):
"""
The createInputVector method takes an Instance as an input. It converts given Instance to the Vector
and insert 1.0 to the first element.
PARAMETERS
----------
instance : Instance
Instance to insert 1.0.
"""
self.x = instance.toVector()
self.x.insert(0, 1.0)
def distance(self, instance1: Instance, instance2: Instance) -> float:
"""
Calculates Mahalanobis distance between two instances. (x^(1) - x^(2)) S (x^(1) - x^(2))^T
PARAMETERS
----------
instance1 : Instance
First instance.
instance2 : Instance
Second instance.
RETURNS
-------
float
Mahalanobis distance between two instances.
"""
v1 = instance1.toVector()
v2 = instance2.toVector()
v1.subtract(v2)
v3 = self.__covarianceInverse.multiplyWithVectorFromLeft(v1)
return v3.dotProduct(v1)
def calculateMetric(self, instance: Instance, Ci: str) -> float:
"""
The calculateMetric method takes an Instance and a String as inputs. It returns the dot product of given
Instance and wi plus w0i.
PARAMETERS
----------
instance : Instance
Instance input.
Ci : str
String input.
RETURNS
-------
float
The dot product of given Instance and wi plus w0i.
"""
xi = instance.toVector()
wi = self.w[Ci]
w0i = self.w0[Ci]
return wi.dotProduct(xi) + w0i
def calculateMetric(self, instance: Instance, Ci: str) -> float:
"""
The calculateMetric method takes an Instance and a String as inputs. It multiplies Matrix Wi with Vector xi
then calculates the dot product of it with xi. Then, again it finds the dot product of wi and xi and returns the
summation with w0i.
PARAMETERS
----------
instance : Instance
Instance input.
Ci : str
String input.
RETURNS
-------
float
The result of Wi.multiplyWithVectorFromLeft(xi).dotProduct(xi) + wi.dotProduct(xi) + w0i.
"""
xi = instance.toVector()
Wi = self.__W[Ci]
wi = self.w[Ci]
w0i = self.w0[Ci]
return Wi.multiplyWithVectorFromLeft(xi).dotProduct(
xi) + wi.dotProduct(xi) + w0i