I'm new to R. I'm looking to remove duplicate rows in a data frame where df$x = "string" AND the next row = the same string
so say I have this column
1. String - remove
2. String
3. A
4. A
5. A
6. String - remove
7. String - remove
8. String
9. A
10. A
The result I want would be
2. String
3. A
4. A
5. A
8. String
9. A
10. A
We can use lead from dplyr and remove rows where the current and next row is "String".
library(dplyr)
df %>%
filter(!(V1 == "String" & lead(V1) == "String"))
# V1
#1 String
#2 A
#3 A
#4 String
#5 A
Using base R, we can do
df[!((df$V1 == "String") & c(df$V1[-1], NA) == "String"),,drop = FALSE]
# V1
#2 String
#3 A
#4 A
#7 String
#8 A
data
df <- structure(list(V1 = c("String", "String", "A", "A", "String",
"String", "String", "A")), .Names = "V1", row.names = c(NA, -8L
), class = "data.frame")
We could create a logical index with duplicated and rleid for subsetting the rows
library(data.table)
setDT(df)[!(duplicated(rleid(V1)) & V1 == 'String')]
# V1
#1: String
#2: A
#3: A
#4: String
#5: A
df <- structure(list(V1 = c("String", "String", "A", "A", "String",
"String", "String", "A")), row.names = c(NA, -8L), class = "data.frame")
