CODEWITHSUNDEEP
r
Panos Kalatzantonakis
Panos Kalatzantonakis

Reputation: 12683

Merge columns based on value

I have a data frame with 3 columns,
I would like to merge the 2 columns with the bigger value into one with the sum.
Function should throw an error whenever a merge is not possible. (e.g: when there's a tie on smaller value 0.3,0.3,0.4)

E.g

|A|     |B|     |C|
0.5     0.3     0.2
0.1     0.7     0.2
0.4     0.4     0.2

resulting data frame:

|X|     |Y|
0.8     0.2  #(x=0.5 + 0.3)
0.9     0.1  #(x=0.7 + 0.2)
0.8     0.2  #(x=0.4 + 0.4)

Thanks in advance for your help

Update:
In case someone has the same problem, I used:

apply(dt, 1, function(x) which(x==min(x)))

to find if there are 2 same minimum values in the data frame

Upvotes: 1

Views: 171

Answers (2)

TheComeOnMan
TheComeOnMan

Reputation: 12875

dt$something <- dt$A + dt$B + dt$C - pmin(dt$A,dt$B,dt$C)

Your extra condition is easier to handle with a data.table

dt <- data.table(dt)
dt[,something := A + B + C - pmin(A,B,C) ]
dt[A==B | B ==C | C==A,something := NA]

Upvotes: 3

A5C1D2H2I1M1N2O1R2T1
A5C1D2H2I1M1N2O1R2T1

Reputation: 193517

Perhaps something like this will get you off to a start:

t(apply(mydf, 1, function(x) {a <- sort(x); c(sum(a[2:3]), a[1])}))
#      [,1] [,2]
# [1,]  0.8  0.2
# [2,]  0.9  0.1
# [3,]  0.8  0.2

You'll need to add your other conditions in though.

Upvotes: 1

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