Basu_Urvi_Project2_Part2

Read and prep file

# load and read the file 
d <- read.csv('/Users/Urvi.Basu/Desktop/project2.data.csv')

# rename the variable 
x <- d$ChatUsage

# check numeric type 
if(!is.numeric(x)){ stop("ChatUsage is not numeric")}

Calculate descriptives with outliers

mean(x); median(x); sd(x); var(x); range(x); IQR(x)

## [1] 3.86

## [1] 3

## [1] 2.364793

## [1] 5.592245

## [1]  0 10

## [1] 3

summary(x)

##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##    0.00    2.00    3.00    3.86    5.00   10.00

Outliers

# identify and remove outliers 
z_max <- (max(x) - mean(x)) / sd(x)
Q1 <- quantile(x, 0.25); Q3 <- quantile(x, 0.75)
I <- IQR(x); LF <- Q1 - 1.5*I; UF <- Q3 + 1.5*I
Outliers <- which(x < LF | x > UF)

chat_nooutliers <- x[x>= LF & x <= UF]

Outliers 

## [1] 13

cat("Z-score of maximum value:", round(z_max, 3), "\n\n")

## Z-score of maximum value: 2.596

cat("Q1:", round(Q1, 3), "\n")

## Q1: 2

cat("Q3:", round(Q3, 3), "\n")

## Q3: 5

cat("IQR:", round(I, 3), "\n\n")

## IQR: 3

cat("Lower Fence:", round(LF, 3), "\n")

## Lower Fence: -2.5

cat("Upper Fence:", round(UF, 3), "\n\n")

## Upper Fence: 9.5

Calculate descriptives without outliers

mean(chat_nooutliers); median(chat_nooutliers); sd(chat_nooutliers); var(chat_nooutliers); range(chat_nooutliers); IQR(chat_nooutliers)

## [1] 3.734694

## [1] 3

## [1] 2.215246

## [1] 4.907313

## [1] 0 9

## [1] 3

summary(chat_nooutliers)

##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   0.000   2.000   3.000   3.735   5.000   9.000

Plots

# Plots (ggplot2)
# histogram 
library(ggplot2)
ggplot(data.frame(chat_nooutliers), aes(chat_nooutliers)) +
geom_histogram(aes(y= after_stat(density)), bins=30) +
geom_density()

# box plot 
ggplot(data.frame(chat_nooutliers), aes(chat_nooutliers="", y=chat_nooutliers)) + geom_boxplot()

# violin plot 
ggplot(data.frame(x), aes(x="", y=x)) +
geom_violin() +
geom_dotplot(binaxis="y", stackdir="center")

## Bin width defaults to 1/30 of the range of the data. Pick better value with
## `binwidth`.