Data Structure (con’t)

data.frame(_data) → two dimension, multiple datatype

data.frame(
  string=c("zero","one"),
  number=c(0,1),
  boolean=c(FALSE,TRUE)
)

---

Add data

rbind(variable_name, variable_name)

df = data.frame(
  column_one=c(1,2,3),
  column_two=c(4,5,6))

rbind( df, c(7,8) )

---

cbind(variable_name, variable_name)

df = data.frame(
  column_one=c(1,2,3),
  column_two=c(4,5,6))

cbind( df, c(9,10,11) )

---

Import data

read.csv(file_path, header=TRUE/FALSE)

df = read.csv("C:/folder/file.csv", header=TRUE)

---

Access column

df = data.frame(
  column_one=c(1,2,3),
  column_two=c(4,5,6))

df["column_one"]
df$column_one
df[,2]

---

Delete column

df = data.frame(
  column_one=c(1,2,3),
  column_two=c(4,5,6))

df$column_one = NULL

---

Data frame function

nrow(variable_name)

nrow(
  data.frame(
    string=c("zero","one","two","three")
  )
)

Result: 4

---

ncol(variable_name)

ncol(
  data.frame(
    one=c("one"),
    two=c("two"),
    three=c("three")
  )
)

Result: 3

---

dim(variable_name)

dim(
  data.frame(one=c("one","two","three"),two=c(1,2,3))
)

---

names(variable_name)

names(
  data.frame(
    name_one=c(1),
    name_two=c(2)
  )
)

---

head(variable_name, quantity)

head(
  data.frame(column=c(1,2,3,4,5)),
  2
)

---

tail(variable_name, quantity)

tail(
  data.frame(column=c(1,2,3,4,5)),
  2
)

---

list(_data) → multi dimension, multiple datatype

a = c(FALSE)
b = c(1,2)
c = c("Three","Four")
list(a, b, c, 5)