Practical Machine Learning week3

data(iris)
library(ggplot2)
library(caret)

## Loading required package: lattice

names(iris)

## [1] "Sepal.Length" "Sepal.Width"  "Petal.Length" "Petal.Width" 
## [5] "Species"

table(iris$Species)

## 
##     setosa versicolor  virginica 
##         50         50         50

inTrain<-createDataPartition(y=iris$Species,p=0.7,list=FALSE)
training<-iris[inTrain,]
testing<-iris[-inTrain,]
#dim(training);dim(testing)
qplot(Petal.Length, Sepal.Length, colour=Species, data=training)

modFit<-train(Species ~., method="rpart", data=training)

## Loading required package: rpart

print(modFit$finalModel)

## n= 105 
## 
## node), split, n, loss, yval, (yprob)
##       * denotes terminal node
## 
## 1) root 105 70 setosa (0.33333333 0.33333333 0.33333333)  
##   2) Petal.Length< 2.45 35  0 setosa (1.00000000 0.00000000 0.00000000) *
##   3) Petal.Length>=2.45 70 35 versicolor (0.00000000 0.50000000 0.50000000)  
##     6) Petal.Length< 4.75 31  1 versicolor (0.00000000 0.96774194 0.03225806) *
##     7) Petal.Length>=4.75 39  5 virginica (0.00000000 0.12820513 0.87179487) *

plot(modFit$finalModel, uniform=TRUE, main="Classification Tree")
text(modFit$finalModel, use.n=TRUE, all=TRUE, cex=.8)

library(rattle)

## Rattle: A free graphical interface for data science with R.
## Version 5.1.0 Copyright (c) 2006-2017 Togaware Pty Ltd.
## Type 'rattle()' to shake, rattle, and roll your data.

fancyRpartPlot(modFit$finalModel)

predict(modFit, newdata=testing)

##  [1] setosa     setosa     setosa     setosa     setosa     setosa    
##  [7] setosa     setosa     setosa     setosa     setosa     setosa    
## [13] setosa     setosa     setosa     versicolor versicolor versicolor
## [19] versicolor versicolor versicolor versicolor virginica  versicolor
## [25] versicolor versicolor versicolor versicolor versicolor versicolor
## [31] virginica  virginica  virginica  virginica  virginica  virginica 
## [37] virginica  virginica  virginica  virginica  virginica  virginica 
## [43] virginica  virginica  virginica 
## Levels: setosa versicolor virginica