Noah Silverman a écrit :
Hi,
I'm trying to find an easy way to do this.
I want to select the top three values of a specific column in a subset
of rows in a data.frame. I'll demonstrate.
Hi,
did you try this?
data[data$A=='x'& data$C<2,]$B # data = your data frame
A B C
x 2 1
x 4 1
x 3 2
y 1 5
y 2 6
y 3 8
I want the top 3 values of B from the data.frame where A=X and C <2
I could extract all the rows where C<2, then sort by B, then take the
first 3. But that seems like the wrong way around, and it also will
get messy with real data of over 100 columns.
Any suggestions?
regards
ML
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