Categorical data and Numerical data

Level of measurements

Data never sleep

Table and Graphical methods

## Characterizing a set of measurements

Example

## Characterizing a set of measurements

Example

We can summarize their frequencies and relative frequencies in a frequency table

1. Input data

# Input computer data

com.stoppage <- c(1,3,1,1,0,1,0,1,1,0,2,2,0,0,0,1,2,1,2,0,0,1,6,4,3,3,1,2,4,0)

1. Summarize frequencies in a frequency table

#summary(com.stoppage)
com.freq <- table(factor(com.stoppage, levels = min(com.stoppage):max(com.stoppage)))
#hist(com.stoppage)

com.freq

## 
##  0  1  2  3  4  5  6 
##  9 10  5  3  2  0  1

1. Construct frequency histogram

• Base plot

barplot(com.freq)

• ggplot

df1 <- as.data.frame(com.freq)
library(ggplot2)
ggplot(data=df1,aes(x=Var1,y=Freq))+
  geom_bar(stat="identity", fill="steelblue")+
  geom_text(aes(label=Freq), vjust=-0.3, size=3.5)

vals <- factor(com.stoppage)
table(vals)

## vals
##  0  1  2  3  4  6 
##  9 10  5  3  2  1

typeof(vals)

## [1] "integer"

dim(table(vals))

## [1] 6

df <- as.data.frame(table(vals))
df

##   vals Freq
## 1    0    9
## 2    1   10
## 3    2    5
## 4    3    3
## 5    4    2
## 6    6    1

library(ggplot2)
ggplot(data=df,aes(x=vals,y=Freq))+
  geom_bar(stat="identity", fill="steelblue")+
  geom_text(aes(label=Freq), vjust=-0.3, size=3.5)

More options in barplot output link