uniform <- runif(1000)
pop1 <- rnorm(10000, mean=100, sd=10)
pop2 <- rnorm(10000, mean=120, sd=10)


sample1 <- sample(pop1, 30, replace=F)
sample2 <- sample(pop2, 30, replace=F)
mean(sample1)
mean(sample2)
t.test(sample1,sample2,var.equal=T)




#pop1 <- rnorm(10000, mean=100, sd=10)
pop1 <- c(rnorm(5000, mean=60, sd=10), rnorm(5000, mean=120, sd=20))

n1 <- 2 # sample size for exp1
n2 <- 10 # sample size for exp2
sam1 <- mean(sample(pop1, n1))
sam2 <- mean(sample(pop1, n2))

for (i in 1:10000) {
 x1 <- sample(pop1, n1)
 x2 <- sample(pop1, n2)
 sam1 <- c(sam1, mean(x1))
 sam2 <- c(sam2, mean(x2))
}

pmean <- hist(pop1, breaks=50)
s1mean <- hist(sam1, breaks=pmean$breaks)
s2mean <- hist(sam2, breaks=pmean$breaks)


plot(pmean$mids, pmean$counts, ylim=c(0,max(c(pmean$counts,s1mean$counts,s2mean$counts))), xlab='values', ylab='frequency', type='l', col='green', lwd=6)
lines(s1mean$mids, s1mean$counts, col='grey', lwd=6)
lines(s2mean$mids, s2mean$counts, col='blue', lwd=6)


x1 <- sample(pop1, n1)
x2 <- sample(pop1, n2)

mean(x1)
sd(x1)
sd(x1)/sqrt(n1)

mean(x2)
sd(x2)
sd(x2)/sqrt(n2)

mean(sam1)
sd(sam1)

mean(sam2)
sd(sam2)



df <- n2-1

tcrit <- qt(0.975,df)
ci <- (sd(x2)/sqrt(n2))*tcrit

c(mean(x2)-ci, mean(x2)+ci)






samp1<-sample(pop1, 1)
samp2<-sample(pop1, 1)
pval<-1

for (i in 1:200) {
 x1 <- sample(pop1, 1)
 x2 <- sample(pop1, 1)
 samp1 <- c(samp1, x1)
 samp2 <- c(samp2, x2)
 pval <- c(pval, t.test(samp1,samp2)$p.value)
}

pval<.05
mean(pval<.05)







sample.data <- read.table("/Users/yasu/Desktop/exampledata.txt", sep=",", header=TRUE)

attach(sample.data)

oncampus.a <- A[Mode=='OnCampus'|Mode=='Trimester']
oncampus.b <- B[Mode=='OnCampus'|Mode=='Trimester']
oncampus.c <- C[Mode=='OnCampus'|Mode=='Trimester']
oncampus.f <- F[Mode=='OnCampus'|Mode=='Trimester']

oncampus.grade <- cbind(oncampus.a, oncampus.b, oncampus.c, oncampus.f)
oncampus.grade <- oncampus.grade/apply(oncampus.grade,1,sum)
on.grade.summary <- apply(oncampus.grade,2,mean)

offcampus.a <- A[Mode=='OffCampus']
offcampus.b <- B[Mode=='OffCampus']
offcampus.c <- C[Mode=='OffCampus']
offcampus.f <- F[Mode=='OffCampus']

offcampus.grade <- cbind(offcampus.a, offcampus.b, offcampus.c, offcampus.f)
offcampus.grade <- offcampus.grade/apply(offcampus.grade,1,sum)
off.grade.summary <- apply(offcampus.grade,2,mean)


webcampus.a <- A[Mode=='WebCampus']
webcampus.b <- B[Mode=='WebCampus']
webcampus.c <- C[Mode=='WebCampus']
webcampus.f <- F[Mode=='WebCampus']

webcampus.grade <- cbind(webcampus.a, webcampus.b, webcampus.c, webcampus.f)
webcampus.grade <- webcampus.grade/apply(webcampus.grade,1,sum)
web.grade.summary <- apply(webcampus.grade,2,mean)

barplot(rbind(on.grade.summary, off.grade.summary, web.grade.summary), names.arg=c('A','B','C','F'), legend.text=c('On Campus','Off Campus', 'Web Campus'), beside=T, xlab='grade', ylab='%')





webcampus.q14sa <- q14SAgree[Mode=='WebCampus']
webcampus.q14a <- q14Agree[Mode=='WebCampus']
webcampus.q14n <- q14Neutral[Mode=='WebCampus']
webcampus.q14d <- q14SDisagree[Mode=='WebCampus']
webcampus.q14sd <- q14SDisagree[Mode=='WebCampus']

webcampus.q14 <- cbind(webcampus.q14sa, webcampus.q14a, webcampus.q14n, webcampus.q14d, webcampus.q14sd)
webcampus.q14 <- webcampus.q14/apply(webcampus.q14,1,sum)
web.q14.summary <- apply(webcampus.q14,2,mean)


offcampus.q14sa <- q14SAgree[Mode=='OffCampus']
offcampus.q14a <- q14Agree[Mode=='OffCampus']
offcampus.q14n <- q14Neutral[Mode=='OffCampus']
offcampus.q14d <- q14SDisagree[Mode=='OffCampus']
offcampus.q14sd <- q14SDisagree[Mode=='OffCampus']

offcampus.q14 <- cbind(offcampus.q14sa, offcampus.q14a, offcampus.q14n, offcampus.q14d, offcampus.q14sd)
offcampus.q14 <- offcampus.q14/apply(offcampus.q14,1,sum)
off.q14.summary <- apply(offcampus.q14,2,mean)


oncampus.q14sa <- q14SAgree[Mode =='OnCampus'|Mode=='Trimester']
oncampus.q14a <- q14Agree[Mode =='OnCampus'|Mode=='Trimester']
oncampus.q14n <- q14Neutral[Mode =='OnCampus'|Mode=='Trimester']
oncampus.q14d <- q14SDisagree[Mode =='OnCampus'|Mode=='Trimester']
oncampus.q14sd <- q14SDisagree[Mode =='OnCampus'|Mode=='Trimester']

oncampus.q14 <- cbind(oncampus.q14sa, oncampus.q14a, oncampus.q14n, oncampus.q14d, oncampus.q14sd)
oncampus.q14 <- oncampus.q14/apply(oncampus.q14,1,sum)
on.q14.summary <- apply(oncampus.q14,2,mean)


barplot(rbind(on.q14.summary, off.q14.summary, web.q14.summary), names.arg=c('s agree','agree','neutral','disagree', 's disagree'), legend.text=c('On Campus','Off Campus', 'Web Campus'), beside=T, xlab='Q type', ylab='%')


oncampus.q14[,1]
offcampus.q14[,1]
webcampus.q14[,1]