CODEWITHSUNDEEP
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oercim
oercim

Reputation: 1848

R-Subset of a data frame conditional to another data frame

Let I have two such data frames:

data frame1(df1):

col1 col2
x    x
x    x
x    y
y    y

data frame2(df2):

col1  col2
1.1   0.1
1.3   1.0
0.3   0.8
0.7   1.6

Desired output data frame(df) is:

col1  col2
0.7   0.8
NA    1.6

Namely, I want to produce a subset of df2, which mirrors df1="y". How can I do that using R? I will be very glad for any help? Thanks a lot.

Upvotes: 2

Views: 212

Answers (1)

Frank
Frank

Reputation: 66819

You can iterate over columns:

lapply(1:ncol(df1),function(i) df2[[i]][df1[[i]]=="y"])

Or similarly:

mapply(function(a,b) a[b=="y"], df2,df1)

The result is a list, not a data.frame, but this seems best (since rows have no meaning).

Upvotes: 3

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