How to get a list of all the different values within a variable

Question

I've always wondered if there's a command in R that gives you the entire domain of values within a variable.

For example, let's say I have the following data.table:

dt
Household Number_of_children
1         0
2         3
3         3

Is there a command along the lines of summary() or str() that would return the list 0, 3?

I believe summary and str only do that when your variable is a character string. I don't know how to do this when your variable is an integer, numeric, etc.

Are you trying to get unique values of a variable? Try unique(dt$Number_of_children) — Katia, Jun 17 '18 at 03:31
List is a special data structure in R. So you should be bit careful about names of data-structures in R. — tired and bored dev, Jun 17 '18 at 03:31

score 3 · Accepted Answer · answered Jun 17 '18 at 03:30

3

You can use unique() function, with column/vector as input.

unique(dt[,'Number_of_children'])

answered Jun 17 '18 at 03:30

tired and bored dev

655
10
30

This is exactly the function I've been looking for. Thanks! – Arturo Sbr Jun 17 '18 at 03:50
1

Also often useful is to replace `unique` here with `table` to show the number of occurrences of each unique value. – rosscova Jun 17 '18 at 03:56

How to get a list of all the different values within a variable

1 Answers1