Advanced Data Analytics Using Python_ With Machine Learning, Deep Learning and NLP Examples ( 2023)

Chapter 3
Supervised Learning Using Python
model.fit(X, y)
model.score(X, y)
print model.predict(x_test)
Nearest Neighbor Classifier
The nearest neighbor classifier is a simple distance-based classifier. It
calculates the distance of test data from the training data and groups
the distances according to the target class. The target class, which has a
minimum average distance from the test instance, is selected as the class
of the test data. A Python example is shown here:
def Distance(point1, point2, length):
distance = 0
for x in range(length):
distance += pow((point1[x] -point2[x]), 2)
return math.sqrt(distance)
def getClosePoints(trainingData, testData, k):
distances = []
length = len(testInstance)-1
for x in range(len(trainingData)):
dist = Distance(testData, trainingDatat[x], length)
distances.append((trainingData[x], dist))
distances.sort(key=operator.itemgetter(1))
close= []
for x in range(k):
close.append(distances[x][0])
return close
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