So a quick question jumping off of this one....
Fast replacing values in dataframe in R
If I want to do this replace but only for certain rows of my data frame, is there a way to add a row specification to:
df [df<0] =0
Something like applying this to rows 40-52 (Doesn't work):
df[df[40:52,] < 0] = 0
Any suggestions? Much appreciated.
Or simply:
df[40:52,][df[40:52,] < 0] <- 0
Here is a test:
test = data.frame(A = c(1,2,-1), B = c(4,-8,5), C = c(1,2,3), D = c(7,8,-9))
#> test
# A B C D
#1 1 4 1 7
#2 2 -8 2 8
#3 -1 5 3 -9
To replace the negative values with 0 for only rows 2 and 3, you can do:
test[2:3,][test[2:3,] < 0] <- 0
and you get
#> test
# A B C D
#1 1 4 1 7
#2 2 0 2 8
#3 0 5 3 0
This is another way, utilizing R's recycling behavior.
df[df < 0 & 1:nrow(df) %in% 40:52] <- 0
