# Radhe Radhe
library(randomForest);library(dplyr);library(caTools)
## randomForest 4.6-14
## Type rfNews() to see new features/changes/bug fixes.
## 
## Attaching package: 'dplyr'
## The following object is masked from 'package:randomForest':
## 
##     combine
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
# Importing the dataset and converting the dataset attribute class into o and 1

dataset = read.csv('diab_1.csv',stringsAsFactors=FALSE)

df <- dataset$class
df[df == "tested_positive"] <-"1"
df[df == "tested_negative"] <-"0"
dataset$class <- df
dataset$class = as.numeric(as.character(dataset$class))

# Splitting the dataset into the Training set and Test set
#install.packages('caTools')

set.seed(789) #for fixing the referance
split = sample.split(dataset$class, SplitRatio = 0.76)
tran_set = subset(dataset, split == TRUE)
test_set = subset(dataset, split == FALSE)

#Fitting the random forest
rf_pima <- randomForest(class ~., data = tran_set, mtry = 8, ntree=171, importance = TRUE)
## Warning in randomForest.default(m, y, ...): The response has five or fewer
## unique values. Are you sure you want to do regression?
# Testing the Model
#install.packages("caret")
library(caret)
## Loading required package: lattice
## Loading required package: ggplot2
## 
## Attaching package: 'ggplot2'
## The following object is masked from 'package:randomForest':
## 
##     margin
rf_probs <- predict(rf_pima, newdata = test_set)
rf_pred <- ifelse(rf_probs > 0.5, 1, 0)
confusionMatrix(as.factor(rf_pred), as.factor(test_set$class))
## Confusion Matrix and Statistics
## 
##           Reference
## Prediction  0  1
##          0 99 23
##          1 21 41
##                                           
##                Accuracy : 0.7609          
##                  95% CI : (0.6926, 0.8206)
##     No Information Rate : 0.6522          
##     P-Value [Acc > NIR] : 0.0009686       
##                                           
##                   Kappa : 0.469           
##                                           
##  Mcnemar's Test P-Value : 0.8801685       
##                                           
##             Sensitivity : 0.8250          
##             Specificity : 0.6406          
##          Pos Pred Value : 0.8115          
##          Neg Pred Value : 0.6613          
##              Prevalence : 0.6522          
##          Detection Rate : 0.5380          
##    Detection Prevalence : 0.6630          
##       Balanced Accuracy : 0.7328          
##                                           
##        'Positive' Class : 0               
## 
ACC_RandomForest <- confusionMatrix(as.factor(rf_pred), as.factor(test_set$class))$overall['Accuracy']

# Random forest graphs
par(mfrow = c(1, 2))
varImpPlot(rf_pima, type = 2, main = "Variable Importance",col = 'black')
plot(rf_pima, main = "Error vs no. of trees grown")

# MODEL lOGISTIC REGRESSION
set.seed(123)
split = sample.split(dataset$class, SplitRatio = 0.75)
Traindata = subset(dataset, split == TRUE)
Testdata = subset(dataset, split == FALSE)
dataset$class <- as.factor(dataset$class)

# Training The Model

glm_Model1 <- glm(class ~., data = Traindata, family = binomial)
summary(glm_Model1)
## 
## Call:
## glm(formula = class ~ ., family = binomial, data = Traindata)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -2.5786  -0.7009  -0.4046   0.6694   2.8366  
## 
## Coefficients:
##              Estimate Std. Error z value Pr(>|z|)    
## (Intercept) -8.597820   0.836126 -10.283  < 2e-16 ***
## preg         0.107268   0.038914   2.756  0.00584 ** 
## plas         0.040055   0.004599   8.709  < 2e-16 ***
## pres        -0.018938   0.006538  -2.897  0.00377 ** 
## skin         0.008982   0.008373   1.073  0.28342    
## insu        -0.003051   0.001179  -2.588  0.00966 ** 
## mass         0.088903   0.017876   4.973 6.58e-07 ***
## pedi         0.794833   0.364194   2.182  0.02908 *  
## age          0.020087   0.011341   1.771  0.07652 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 745.11  on 575  degrees of freedom
## Residual deviance: 527.03  on 567  degrees of freedom
## AIC: 545.03
## 
## Number of Fisher Scoring iterations: 5
# Variables with the p_values greather than 0.01 are insignificant

glm_Model2 <- update(glm_Model1, ~. - skin - insu - age )
summary(glm_Model2)
## 
## Call:
## glm(formula = class ~ preg + plas + pres + mass + pedi, family = binomial, 
##     data = Traindata)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -2.7239  -0.7192  -0.4141   0.6964   2.8894  
## 
## Coefficients:
##              Estimate Std. Error z value Pr(>|z|)    
## (Intercept) -7.821602   0.770056 -10.157  < 2e-16 ***
## preg         0.151722   0.033154   4.576 4.73e-06 ***
## plas         0.036884   0.004024   9.165  < 2e-16 ***
## pres        -0.015398   0.006118  -2.517   0.0118 *  
## mass         0.084551   0.016569   5.103 3.35e-07 ***
## pedi         0.690636   0.354260   1.950   0.0512 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 745.11  on 575  degrees of freedom
## Residual deviance: 538.28  on 570  degrees of freedom
## AIC: 550.28
## 
## Number of Fisher Scoring iterations: 5
# Testing the Model
glm_probs <- predict(glm_Model2, newdata = Testdata, type = "response")
glm_pred <- ifelse(glm_probs > 0.5, 1, 0)
#print("Confusion Matrix for logistic regression"); 
table(Predicted = glm_pred, Actual = Testdata$class)
##          Actual
## Predicted   0   1
##         0 102  29
##         1  23  38
confusionMatrix(as.factor(glm_pred), as.factor(Testdata$class) ) # Confusion Matrix for logistic regression
## Confusion Matrix and Statistics
## 
##           Reference
## Prediction   0   1
##          0 102  29
##          1  23  38
##                                           
##                Accuracy : 0.7292          
##                  95% CI : (0.6605, 0.7906)
##     No Information Rate : 0.651           
##     P-Value [Acc > NIR] : 0.01287         
##                                           
##                   Kappa : 0.3913          
##                                           
##  Mcnemar's Test P-Value : 0.48807         
##                                           
##             Sensitivity : 0.8160          
##             Specificity : 0.5672          
##          Pos Pred Value : 0.7786          
##          Neg Pred Value : 0.6230          
##              Prevalence : 0.6510          
##          Detection Rate : 0.5312          
##    Detection Prevalence : 0.6823          
##       Balanced Accuracy : 0.6916          
##                                           
##        'Positive' Class : 0               
## 
#Accuracy of the GLM
Accur_GLM <- confusionMatrix(as.factor(glm_pred), as.factor(Testdata$class) )$overall['Accuracy']
Accur_GLM
##  Accuracy 
## 0.7291667