Is it possible in R to subset a dataframe by more than one factor, all at
once?
For instance, I have the dataframe:
>data
p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 pred
1 0 1 0 0 0 0 0 0 0 0 0.5862069
4 0 0 0 0 0 0 0 0 0 1 0.5862069
5 0 0 0 0 0 0 1 0 0 0 0.5862069
6 0 0 0 0 0 0 0 1 0 0 0.5862069
7 0 0 1 0 0 0 0 0 0 0 0.5862069
9 0 0 0 0 1 0 0 0 0 0 0.5862069
20 0 1 1 0 0 0 0 0 0 0 0.5862069
22 0 1 0 0 1 0 0 0 0 0 0.5862069
24 0 1 0 0 0 0 1 0 0 0 0.5862069
25 0 1 0 0 0 0 0 1 0 0 0.5862069
27 0 1 0 0 0 0 0 0 0 1 0.5862069
If I want to subset only those points that have p4 = 1, I do:
> subset(data,p4 == 1)
And that's fine. Now suppose I want to subset those that not only have p4
= 1, but also p6 = 1.
I tried subset(data,p4 == 1 && p6 == 1) or subset(data,p4==1 & p6==1).
But it didn't work.
Then I found a clumsy way to do it :
subset(subset(data,p4==1),p6==1)
Which works. But it soon gets very clumsy as the number of conditions
increase (I end up with a really large number of nested subsets). Is there a
simpler way to do that?
--
Subseting by more than one factor...
3 messages · Fernando Henrique Ferraz P. da Rosa, Sundar Dorai-Raj, Douglas Bates
Fernando Henrique Ferraz Pereira da Rosa wrote:
Is it possible in R to subset a dataframe by more than one factor, all at
once?
For instance, I have the dataframe:
>data
p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 pred 1 0 1 0 0 0 0 0 0 0 0 0.5862069 4 0 0 0 0 0 0 0 0 0 1 0.5862069 5 0 0 0 0 0 0 1 0 0 0 0.5862069 6 0 0 0 0 0 0 0 1 0 0 0.5862069 7 0 0 1 0 0 0 0 0 0 0 0.5862069 9 0 0 0 0 1 0 0 0 0 0 0.5862069 20 0 1 1 0 0 0 0 0 0 0 0.5862069 22 0 1 0 0 1 0 0 0 0 0 0.5862069 24 0 1 0 0 0 0 1 0 0 0 0.5862069 25 0 1 0 0 0 0 0 1 0 0 0.5862069 27 0 1 0 0 0 0 0 0 0 1 0.5862069 If I want to subset only those points that have p4 = 1, I do:
> subset(data,p4 == 1)
And that's fine. Now suppose I want to subset those that not only have p4 = 1, but also p6 = 1. I tried subset(data,p4 == 1 && p6 == 1) or subset(data,p4==1 & p6==1). But it didn't work.
It didn't? It does for me:
R> subset(z, p4 == 1 & p6 == 1)
[1] p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 pred
<0 rows> (or 0-length row.names)
R> subset(z, p2 == 1 & p8 == 1)
p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 pred
10 0 1 0 0 0 0 0 1 0 0 0.5862069
R> subset(z, (p2 == 1 & p3 == 0) | p5 == 1)
p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 pred
1 0 1 0 0 0 0 0 0 0 0 0.5862069
6 0 0 0 0 1 0 0 0 0 0 0.5862069
8 0 1 0 0 1 0 0 0 0 0 0.5862069
9 0 1 0 0 0 0 1 0 0 0 0.5862069
10 0 1 0 0 0 0 0 1 0 0 0.5862069
11 0 1 0 0 0 0 0 0 0 1 0.5862069
R> version
_
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status
major 1
minor 7.0
year 2003
month 04
day 16
language R
R>
[snip]
Regards,
Sundar
Fernando Henrique Ferraz Pereira da Rosa <mentus at gmx.de> writes:
Is it possible in R to subset a dataframe by more than one factor, all at
once?
For instance, I have the dataframe:
>data
p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 pred 1 0 1 0 0 0 0 0 0 0 0 0.5862069 4 0 0 0 0 0 0 0 0 0 1 0.5862069 5 0 0 0 0 0 0 1 0 0 0 0.5862069 6 0 0 0 0 0 0 0 1 0 0 0.5862069 7 0 0 1 0 0 0 0 0 0 0 0.5862069 9 0 0 0 0 1 0 0 0 0 0 0.5862069 20 0 1 1 0 0 0 0 0 0 0 0.5862069 22 0 1 0 0 1 0 0 0 0 0 0.5862069 24 0 1 0 0 0 0 1 0 0 0 0.5862069 25 0 1 0 0 0 0 0 1 0 0 0.5862069 27 0 1 0 0 0 0 0 0 0 1 0.5862069 If I want to subset only those points that have p4 = 1, I do:
> subset(data,p4 == 1)
And that's fine. Now suppose I want to subset those that not only have p4 = 1, but also p6 = 1. I tried subset(data,p4 == 1 && p6 == 1) or subset(data,p4==1 & p6==1).
As Sundar pointed out it is the second form that you want. When intersecting conditions in subset() use &, not &&. The way that you pasted the output in your message the column names did not align with the columns. I changed this in the part that I quoted above. This shows that you chose the wrong example, I think, because that intersection is empty. Try subset(data, p2 == 1 & p3 == 1) instead.