CODEWITHSUNDEEP
rdataframe
ANmike
ANmike

Reputation: 267

Calculate New Mean() and Max() value for each row in a particular column in R

I need to do segmentation of a dataframe based on some conditions, say mean() and max().

here is my dataframe df with one variable A. 

    A
    0
    0
    3
    2
    4
    3  
   ...

I need to create two more columns mean and max for each row of this column,
Expected Output 

    A      mean                                      max
    0       0                                         0
    0       0(mean(A[1], A[2]))                       0(max(A[1], A[2]))
    3       1(mean(A[1],A[2],A[3]))                   3(max(A[1],A[2],A[3]))
    2       1.25(mean(A[1],A[2],A[3],A[4]))           3(max(A[1],A[2],A[3],A[4]))
    4       1.8(mean(A[1],A[2],A[3],A[4],A[5]))       4(max(A[1],A[2],A[3],A[4],A[5]))
    3       2(mean(A[1],A[2],A[3],A[4],A[5],A[6]))    4(max(A[1],A[2],A[3],A[4],A[5],A[6]))
   ...       ...                                      ...

What could be the optimal way to perform this in R?

Upvotes: 1

Views: 46

Answers (1)

Brandon
Brandon

Reputation: 1904

dplyr package has many cumulative functions built in. Here's an example. 

> library(dplyr)
> btest <- data.frame(a = c(0,0,3,4,2,3), b = rnorm(6))
> btest %>% mutate(mean = cummean(a), max = cummax(a))
  a          b mean max
1 0 -1.6028412 0.00   0
2 0  0.1953723 0.00   0
3 3  0.2022246 1.00   3
4 4 -0.2744182 1.75   4
5 2  0.3343044 1.80   4
6 3  0.2081762 2.00   4

Upvotes: 3

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