I have a very basic R question but I am having a hard time trying to get the right answer. I have a data frame that looks like this:
ind<-rep(1:4,each=24)
hour<-rep(seq(0,23,by=1),4)
depth<-runif(length(ind),1,50)
df<-data.frame(cbind(species,ind,hour,depth))
df$depth<-as.numeric(df$depth)
What I would like it to select AND replace all the rows where depth < 10 (for example) with zero, but I want to keep all the information associated to those rows and the original dimensions of the data frame.
I have try the following but this does not work.
df[df$depth<10]<-0
Any suggestions?
2 Answers
# reassign depth values under 10 to zero
df$depth[df$depth<10] <- 0
(For the columns that are factors, you can only assign values that are factor levels. If you wanted to assign a value that wasn't currently a factor level, you would need to create the additional level first:
levels(df$species) <- c(levels(df$species), "unknown")
df$species[df$depth<10] <- "unknown"
I arrived here from a google search, since my other code is 'tidy' so leaving the 'tidy' way for anyone who else who may find it useful
library(dplyr)
iris %>%
mutate(Species = ifelse(as.character(Species) == "virginica", "newValue", as.character(Species)))
