CODEWITHSUNDEEP
rdataframecountrow
Alex Germain
Alex Germain

Reputation: 441

Is there an R function for counting same value on a row?

I'm looking for a function which could gives me the number of times the same string is present on a line by returning this number in a new column with this character string as name. Let's take an example: 

 df <- data.frame(
   Year = rnorm(3), 
   hour = rnorm(3), 
   LOT = rnorm(3), 
   S123_AA = c('ABF4576','AG4633','AWW07954'), 
   S135_AA = c('ABF5403','ABF4576','A64ED56'), 
   S1763_BB = c('BF50343','BGF4761','B76WW56'),  
   S173_BB = c('BF50343','BDZ4641','B917656') 
 )

So, on the first line we observe twice `BF50343 and I'm looking to build new columns in order to get:

 df <- data.frame(
   Year = rnorm(3), 
   hour = rnorm(3), 
   LOT = rnorm(3), 
   S123_AA = c('ABF4576','AG4633','AWW07954'), 
   S135_AA = c('ABF5403','ABF4576','A64ED56'), 
   S1763_BB = c('BF50343','BGF4761','B76WW56'),  
   S173_BB = c('BF50343','BDZ4641','B917656'),
   ABF4576 = c(1,1,0),
   AG4633 = c(0,1,0),
   AWW07954 = c(0,0,1),
   ABF5403 = c(1,0,0),
   A64ED56 = c(0,0,1),
   BF50343 = c(2,0,0),
   BGF4761 = c(0,1,0),
   B76WW56 = c(0,0,1),
   BDZ4641 = c(0,1,0),
   B917656 = c(0,0,1)
)

If you have any idea to develop, thanks for your time

Upvotes: 0

Views: 87

Answers (1)

tamaba
tamaba

Reputation: 51

You can use lapply to loop over the unique values of your character variables:

cols <- !(colnames(df) %in% c("Year", "hour", "LOT")) ## variables of interest
vals <- as.character(unique(unlist(df[cols]))) ## unique values
res <- do.call("cbind", lapply(vals, function(x) rowSums(df[cols] == x)))
colnames(res) <- vals
df <- cbind(df, res)

Upvotes: 1

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