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k Fold Cross Validation R.R
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k Fold Cross Validation R.R
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#k-Fold Cross Validation
# Importing the dataset
dataset = read.csv('Social_Network_Ads.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$Purchased, SplitRatio = 0.75)
training_set = subset(dataset, split == TRUE)
test_set = subset(dataset, split == FALSE)
# Feature Scaling
training_set[-3] = scale(training_set[-3])
test_set[-3] = scale(test_set[-3])
# Fitting Kernel SVM to the Training set
# install.packages('e1071')
library(e1071)
classifier = svm(formula = Purchased~.,
data = training_set,
type = 'C-classification',
kernel = 'radial')
# Predicting the Test set results
y_pred = predict(classifier, newdata = test_set[-3])
# Making the Confusion Matrix
cm = table(test_set[, 3], y_pred)
#Applying k-fold cross validation
#install.packages('caret')
library(caret)
folds = createFolds(training_set$Purchased, k = 10)
cv=lapply(folds, function(x) {
training_fold = training_set[-x,]
test_fold = training_set[x,]
classifier = svm(formula = Purchased ~ .,
data = training_fold,
type = 'C-classification',
kernel = 'radial')
y_pred = predict(classifier, newdata = test_fold[-3])
cm = table(test_fold[, 3], y_pred)
accuracy = (cm[1,1]+ cm[2,2])/(cm[1,1]+cm[1,2]+cm[2,1]+cm[2,2])
return(accuracy)
})
accuracy = mean(as.numeric(cv))
#Apply Grid Search to find the best parameters
classifier = train(form = Purchased~., data=training_set, method ='svmRadial')
classifier
classifier$bestTune
# Visualising the Training set results
library(ElemStatLearn)
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 = 'Kernel 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, 'springgreen3', 'tomato'))
points(set, pch = 21, bg = ifelse(set[, 3] == 1, 'green4', 'red3'))
# Visualising the Test set results
library(ElemStatLearn)
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 = 'Kernel 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, 'springgreen3', 'tomato'))
points(set, pch = 21, bg = ifelse(set[, 3] == 1, 'green4', 'red3'))