How do I Divide Values in a Column by the Value in the Last Cell?-CodePudding

So I am working in R, and I am trying to write a function. But I reached a roadblock.

I have the following df:

Number	Freq	CumFreq
00.1	2	2
00.5	1	3

...so on and so forth.

I'd like to have it so the numbers in df$CumFreq are divided by the last cell in the df$CumFreq, and create a new column. For instance:

Number	Freq	CumFreq	CF/n
00.1	2	2	0.667
00.5	1	3	1

Any advice on how to write this out?

CodePudding user response：

You can try

df$CFn <- with(df,CumFreq/sum(Freq))

df$CFn <- with(df,CumFreq/tail(CumFreq,1))

CodePudding user response：

Here's a dplyr approach using mutate:

df %>% mutate("CF/n" = CumFreq/sum(Freq))

  Number Freq CumFreq      CF/n
1   00.1    2       2 0.6666667
2   00.5    1       3 1.0000000