Thursday 23 May 2019

SVM R


# Importing the dataset

dataset = read.csv(‘social.csv')
dataset = dataset[3:5]

# Encoding the target feature as factor

dataset$Purchased = factor(dataset$Purchased, levels = c(0, 1))

###########################################

# Splitting the dataset into the Training set and Test set

install.packages('caTools')
library(caTools)

set.seed(123)
split = sample.split(dataset$Purchased, SplitRatio = 0.75)

training_set = subset(dataset, split == TRUE)
test_set = subset(dataset, split == FALSE)
View(training_set)
View(test_set)

# Feature Scaling

training_set[-3] = scale(training_set[-3])
test_set[-3] = scale(test_set[-3])

View(training_set)
View(test_set)
##############################################

# Fitting SVM to the Training set
install.packages('e1071')
library(e1071)

classifier = svm(formula = Purchased ~ .,
                 data = training_set,
                 type = 'C-classification',
                 kernel = 'linear')

print(classifier)

# Predicting the Test set results

y_pred = predict(classifier, newdata = test_set[-3])


# Making the Confusion Matrix

cm = table(test_set[, 3], y_pred)
print(cm)
################################################

#Visualizing the Training set results

# installing library ElemStatLearn
library(ElemStatLearn)

# Plotting the training data set results
set = training_set
X1 = seq(min(set[, 1]) - 1, max(set[, 1]) + 1, by = 0.01)
X2 = seq(min(set[, 2]) - 1, max(set[, 2]) + 1, by = 0.01)

grid_set = expand.grid(X1, X2)
colnames(grid_set) = c('Age', 'EstimatedSalary')
y_grid = predict(classifier, newdata = grid_set)

plot(set[, -3],
     main = 'SVM (Training set)',
     xlab = 'Age', ylab = 'Estimated Salary',
     xlim = range(X1), ylim = range(X2))

contour(X1, X2, matrix(as.numeric(y_grid), length(X1), length(X2)), add = TRUE)
points(grid_set, pch = '.', col = ifelse(y_grid == 1, 'coral1', 'aquamarine'))
points(set, pch = 21, bg = ifelse(set[, 3] == 1, 'green4', 'red3'))

##################################################

#Visualizing the Test set results
set = test_set
X1 = seq(min(set[, 1]) - 1, max(set[, 1]) + 1, by = 0.01)
X2 = seq(min(set[, 2]) - 1, max(set[, 2]) + 1, by = 0.01)

grid_set = expand.grid(X1, X2)
colnames(grid_set) = c('Age', 'EstimatedSalary')
y_grid = predict(classifier, newdata = grid_set)

plot(set[, -3], main = 'SVM (Test set)',
     xlab = 'Age', ylab = 'Estimated Salary',
     xlim = range(X1), ylim = range(X2))

contour(X1, X2, matrix(as.numeric(y_grid), length(X1), length(X2)), add = TRUE)

points(grid_set, pch = '.', col = ifelse(y_grid == 1, 'coral1', 'aquamarine'))

points(set, pch = 21, bg = ifelse(set[, 3] == 1, 'green4', 'red3'))

#############################################

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