Data i have
id <- c(1,1,2,2,3,3,4,4,5,5)
amt <- c(250,NA,750,NA,750,NA,500,NA,750,NA)
dv <- c(NA,1,NA,2,NA,1,NA,5,NA,4)
df <- data.frame(id,amt,dv)
now i want to select ids who have amt of 750
output i need
id <- c(2,2,3,3,5,5)
amt <- c(750,NA,750,NA,750,NA)
dv <- c(NA,2,NA,1,NA,4)
df <- data.frame(id,amt,dv)
please help me to do this .
thanks