Rのデータフレーム(data.frame)について ref: http://qiita.com/14021939/items/3436a153119bb88d49df

file0.txt

$ R
> name <- c('suzuki','sato','yamada')
> height  <- c('172','165','184')
> weight <- c('60','58','75')
> users_table <- data.frame(name,height,weight)
> users_table
    name height weight
1 suzuki    172     60
2   sato    165     58
3 yamada    184     75

file1.txt

> users_table[c('name')]
    name
1 suzuki
2   sato
3 yamada

> users_table[c('height')]
  height
1    172
2    165
3    184

> users_table[c('height','weight')]
  height weight
1    172     60
2    165     58
3    184     75

file2.txt

> users_table$name
[1] suzuki sato   yamada
Levels: sato suzuki yamada

file3.txt

> with(users_table, height[ name == "yamada"])
[1] 184
Levels: 165 172 184

file4.txt

> users_table
    name height weight
1 suzuki    172     60
2   sato    165     58
3 yamada    184     75

> point <- c(100,30,40)
> users_table <- data.frame(users_table, point)

> users_table
    name height weight point
1 suzuki    172     60   100
2   sato    165     58    30
3 yamada    184     75    40