# Options
# Surpress scientific notations, digits and lines
options(scipen = 999, digits = 10, max.print = 99999999)
 # Assignment 1
attach(DELL_DATA_cleaned)
library(psych)

summary(DELL_DATA_cleaned)
describe(DELL_DATA_cleaned)

library(naniar)
vis_miss(DELL_DATA_cleaned)

# Chisquare Tests
prop.table(table(q14))

chisq.test(table(q14)p=c(0.55,0.45))

chisq.test(table(q14), p=c(0.55,0.45))

chisq.test(q13, SAMPLE, correct = FALSE)
E<-chisq.test(q13, SAMPLE, correct = FALSE)
str(E)
E$expected
E$expected<5
E$expected<1

chisq.test(q13, SAMPLE, correct = FALSE, simulate.p.value=TRUE, B=10000)

fisher.test(table(q13, SAMPLE), workspace = 2000000)

library(vcd)
assocstats(table(q13, SAMPLE))


# Paired t test
t.test(q5, q4, paired = TRUE, alternative = "greater")

# Nonpair: wilsoxon
wilcox.test(q5, q4, paired = TRUE, exact = FALSE, correct = FALSE)

library(coin)
wilcoxsign_test(q5 - q4, zero.method="wilcoxon", distribution="asymptotic")

# Oneway ANOVA

options(contrasts = c("contr.sum","contr.poly"))
FIT.02<- aov(q6~ factor(q11), data = DELL_DATA_cleaned)


# DELL experiment
attach(DELL_EXP)

FIT.02<- aov(ATT ~ OL + factor(BRAND)*factor(PRODUCT), data = DELL_EXP)
summary(FIT.02)
Anova(FIT.02, type=3)

# Plots
plot(FIT.02)
attach(DELL_EXP)
interaction.plot(factor(BRAND),factor(PRODUCT), ATT)

FIT.03<- lm(ATT ~ OL + factor(BRAND)*factor(PRODUCT), data = DELL_EXP)
summary(FIT.03)