CODEWITHSUNDEEP
rdataframe
Barnaby
Barnaby

Reputation: 1480

frequency of elements in a data frame

I have the following data frame (this is an example and the dataframe can contain more columns) 

SelectVar 
     a    b    c    l    p    v   aa   ff
1 Dxa2 Dxa2 Dxa2 Dxa2 Dxa2 Dxb2 Dxb2 Dxb2
2 Dxb2 Dxb2 Dxb2 Dxd2 Dxi2 Dxc2 Dxd2 Dxi2
3 Dxc2 Dxd2 Dxi2 Dxi2 tneg Dxd2 Dxi2 tneg

I would like to count the frequency of the elements without convert it into a vector and using table or by indicating the element like in 

length(SelectVar[SelectVar=="Dxa2"])

Is there any other way as to count the frequencies of the elements than the two mentioned in the above paragraph for the sample dataframe.

Upvotes: 0

Views: 1451

Answers (1)

Ananta
Ananta

Reputation: 3711

I think you asked the same question yesterday, Counting the frequency of an element in a data frame

answer modified from, dickoa's answer to previous question instead of data.frame, if you make it matrix, table() does not need vectorization and it should work. 

df <- read.table(text = "   b    c    e    f    g    h    j 
1 Dxa2 Dxa2 Dxa2 Dxa2 Dxa2 Dxa2 Dxa2
2 Dxb2 Dxb2 Dxb2 Dxb2 Dxc2 Dxc2 Dxc2
3 Dxd2 Dxi2 tneg tpos Dxd2 Dxi2 tneg", header = TRUE, row.names = 1)

ll<-data.frame(table(as.matrix(df)))

now, you can sort by freq and select top 3

head(ll[order(ll$Freq, decreasing=T),],3)

Upvotes: 2

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