eda.shape <- function(x)
  {
    par(mfrow = c(2, 2))
    hist(x)
    boxplot(x)
    iqd <- summary(x)[5] - summary(x)[2]
    plot(density(x,width=2*iqd), xlab = "x",ylab = "", type = "l")
    qqnorm(x)
    qqline(x)
  }

eda.ts <- function(x)
 {
    par(mfrow=c(2,1))
    ts.plot(x)
    acf(x)
    invisible()
 }

x <- rnorm(100)
eda.shape(x)
eda.ts(x)

library(MASS)
cats
male   <-  cats[cats$Sex=="M",]$Hwt
female <-  cats[cats$Sex=="F",]$Hwt
eda.shape(male)

t.test(male, mu=10)
t.test(male, mu=10, conf.level=0.99)

wilcox.test(male, mu=10)

eda.shape(female)

var.test(male,female)

t.test(male,female,var.equal=T)

t.test(male,female,var.equal=F)

wilcox.test(male,female)

x <- runif(20)
y <- 2+3*x+rnorm(20)
plot(x,y,main="X versus Y")

cor.test(x,y)

cor.test(x,y, alt="l")

z1<-rnorm(50)
z2<-rnorm(50)
z3<-runif(50)
par(mfrow=c(2,1))
plot.ecdf(z1,verticals=TRUE, col.p="white",col.v="black", main="Empirical CDF of z1 and z2")
plot(ecdf(z2),add=TRUE,verticals=TRUE,col.p="white",col.v="black",lty="dotted")
plot.ecdf(z1,verticals=TRUE, col.p="white",col.v="black",main="Empirical CDF of z1 and z3")
plot(ecdf(z3),add=TRUE,verticals=TRUE,col.p="white",col.v="black",lty="dotted")

ks.test(z1,"pnorm")

ks.test(z1,z2)
ks.test(z1,z3)

binom.test(226,500,p=0.5)

binom.test(226,500,p=0.4)

prop.test(266,500)

x<-rnorm(100)
y<-sum(x>0)
binom.test(y,100)

z<-rnorm(100)
d<-x-z
binom.test(sum(d>0),length(d))

x<-c(80,100)
n<-c(200,150)
prop.test(x,n)

library("gmodels")
library("faraway")
attach(solder)
names(solder)
X<-table(Solder,Mask)
X
summary(X)
cross<-xtabs(~Solder+Mask)
cross

CrossTable(cross)

iqdata<-read.table("iqdata.txt")
attach(iqdata)
scorend <- iqdata$V2[V1=="nd"]
scored <- iqdata$V2[V1=="d"]
boxplot(scorend, scored, names=c("Non-depressed mothers","Depressed mothers"))
par(mfrow=c(2,1))
hist(scorend, xlab="IQ of children from Non-depressed mothers")
hist(scored, xlab="IQ of children from depressed mothers")
qqnorm(scorend,main="")
qqline(scorend)
title(main="Normal Probability plot for IQ of children from Non-depressed mothers")
qqnorm(scored,main="")
qqline(scored)
title(main="Normal Probability plot for IQ of children from depressed mothers")

t.test(scorend,scored,var.equal=T)

var.test(scorend,scored)

var.test(scorend[scorend>50],scored[scored>50])

t.test(scorend[scorend>50],scored[scored>50],var.equal=T)