1.5 Identifying Variable Types
The str function is short for structure. This shows you the variable names, what data types R thinks each variable are, and some of the raw data.
str(depress)
## 'data.frame': 294 obs. of 37 variables:
## $ id : int 1 2 3 4 5 6 7 8 9 10 ...
## $ sex : int 2 1 2 2 2 1 2 1 2 1 ...
## $ age : int 68 58 45 50 33 24 58 22 47 30 ...
## $ marital : int 5 3 2 3 4 2 2 1 2 2 ...
## $ educat : int 2 4 3 3 3 3 2 3 3 2 ...
## $ employ : int 4 1 1 3 1 1 5 1 4 1 ...
## $ income : int 4 15 28 9 35 11 11 9 23 35 ...
## $ relig : int 1 1 1 1 1 1 1 1 2 4 ...
## $ c1 : int 0 0 0 0 0 0 2 0 0 0 ...
## $ c2 : int 0 0 0 0 0 0 1 1 1 0 ...
## $ c3 : int 0 1 0 0 0 0 1 2 1 0 ...
## $ c4 : int 0 0 0 0 0 0 2 0 0 0 ...
## $ c5 : int 0 0 1 1 0 0 1 2 0 0 ...
## $ c6 : int 0 0 0 1 0 0 0 1 3 0 ...
## $ c7 : int 0 0 0 0 0 0 0 0 0 0 ...
## $ c8 : int 0 0 0 3 3 0 2 0 0 0 ...
## $ c9 : int 0 0 0 0 3 1 2 0 0 0 ...
## $ c10 : int 0 0 0 0 0 0 0 0 0 0 ...
## $ c11 : int 0 0 0 0 0 0 0 0 0 0 ...
## $ c12 : int 0 1 0 0 0 1 0 0 3 0 ...
## $ c13 : int 0 0 0 0 0 2 0 0 0 0 ...
## $ c14 : int 0 0 1 0 0 0 0 0 3 0 ...
## $ c15 : int 0 1 1 0 0 0 3 0 2 0 ...
## $ c16 : int 0 0 1 0 0 2 0 1 3 0 ...
## $ c17 : int 0 1 0 0 0 1 0 1 0 0 ...
## $ c18 : int 0 0 0 0 0 0 0 1 0 0 ...
## $ c19 : int 0 0 0 0 0 0 0 1 0 0 ...
## $ c20 : int 0 0 0 0 0 0 1 0 0 0 ...
## $ cesd : int 0 4 4 5 6 7 15 10 16 0 ...
## $ cases : int 0 0 0 0 0 0 0 0 1 0 ...
## $ drink : int 2 1 1 2 1 1 2 2 1 1 ...
## $ health : int 2 1 2 1 1 1 3 1 4 1 ...
## $ regdoc : int 1 1 1 1 1 1 1 2 1 1 ...
## $ treat : int 1 1 1 2 1 1 1 2 1 2 ...
## $ beddays : int 0 0 0 0 1 0 0 0 1 0 ...
## $ acuteill: int 0 0 0 0 1 1 1 1 0 0 ...
## $ chronill: int 1 1 0 1 0 1 1 0 1 0 ...A tidyverse alternative is glimpse()
glimpse(depress)
## Rows: 294
## Columns: 37
## $ id <int> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18…
## $ sex <int> 2, 1, 2, 2, 2, 1, 2, 1, 2, 1, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1, 2…
## $ age <int> 68, 58, 45, 50, 33, 24, 58, 22, 47, 30, 20, 57, 39, 61, 23, 2…
## $ marital <int> 5, 3, 2, 3, 4, 2, 2, 1, 2, 2, 1, 2, 2, 5, 2, 1, 1, 4, 1, 5, 1…
## $ educat <int> 2, 4, 3, 3, 3, 3, 2, 3, 3, 2, 2, 3, 2, 3, 3, 2, 4, 2, 6, 2, 3…
## $ employ <int> 4, 1, 1, 3, 1, 1, 5, 1, 4, 1, 3, 2, 1, 4, 1, 1, 1, 3, 1, 4, 1…
## $ income <int> 4, 15, 28, 9, 35, 11, 11, 9, 23, 35, 25, 24, 28, 13, 15, 6, 8…
## $ relig <int> 1, 1, 1, 1, 1, 1, 1, 1, 2, 4, 4, 1, 1, 1, 2, 1, 1, 1, 1, 4, 2…
## $ c1 <int> 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 1, 3, 1, 0, 0, 0…
## $ c2 <int> 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 3, 0, 0, 0, 0…
## $ c3 <int> 0, 1, 0, 0, 0, 0, 1, 2, 1, 0, 1, 0, 0, 0, 0, 2, 2, 1, 0, 0, 0…
## $ c4 <int> 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 1, 0, 0, 0…
## $ c5 <int> 0, 0, 1, 1, 0, 0, 1, 2, 0, 0, 1, 0, 0, 1, 0, 1, 3, 1, 0, 0, 0…
## $ c6 <int> 0, 0, 0, 1, 0, 0, 0, 1, 3, 0, 2, 0, 0, 0, 0, 1, 3, 0, 0, 0, 0…
## $ c7 <int> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0…
## $ c8 <int> 0, 0, 0, 3, 3, 0, 2, 0, 0, 0, 0, 0, 0, 1, 0, 1, 2, 0, 0, 3, 0…
## $ c9 <int> 0, 0, 0, 0, 3, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 0, 0, 0, 3…
## $ c10 <int> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0…
## $ c11 <int> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0…
## $ c12 <int> 0, 1, 0, 0, 0, 1, 0, 0, 3, 0, 1, 0, 1, 1, 0, 1, 2, 0, 0, 0, 0…
## $ c13 <int> 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0…
## $ c14 <int> 0, 0, 1, 0, 0, 0, 0, 0, 3, 0, 2, 0, 2, 0, 0, 2, 2, 0, 0, 0, 0…
## $ c15 <int> 0, 1, 1, 0, 0, 0, 3, 0, 2, 0, 1, 2, 0, 0, 1, 1, 3, 0, 0, 0, 0…
## $ c16 <int> 0, 0, 1, 0, 0, 2, 0, 1, 3, 0, 1, 2, 1, 0, 3, 1, 2, 0, 0, 0, 0…
## $ c17 <int> 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 2, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0…
## $ c18 <int> 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 3, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0…
## $ c19 <int> 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0, 0, 0…
## $ c20 <int> 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 3, 0, 0, 0, 0…
## $ cesd <int> 0, 4, 4, 5, 6, 7, 15, 10, 16, 0, 18, 4, 8, 4, 8, 21, 42, 6, 0…
## $ cases <int> 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0…
## $ drink <int> 2, 1, 1, 2, 1, 1, 2, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 1, 1…
## $ health <int> 2, 1, 2, 1, 1, 1, 3, 1, 4, 1, 2, 2, 3, 1, 1, 3, 1, 3, 2, 2, 1…
## $ regdoc <int> 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1…
## $ treat <int> 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 2, 1, 1, 1, 2, 1, 2, 1, 2, 2, 1…
## $ beddays <int> 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0…
## $ acuteill <int> 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0…
## $ chronill <int> 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1…Right away this tells me that R thinks all variables are numeric integers, not categorical variables. Many of these will have to be changed. We’ll get to that in a moment.
Just check the data type of one variable