which

Let's make a small example first, that computes in R: x<- c(1,3,1,4,2) max(which(x<2)) [1] 3 Now, I would like to do this not just for one value 2, but for many values simultaneously. It should give me something like that: max(which(x<c(1,2,3,4,5,6))) [1] NA 3 5 5 5 5 Of course I could run a for loop, but that is very slow: for(i in c(1,2,3,4,5,6)){ test[i]<-max(which(x<i)) } Is there a fast way to do this? Find the max index of each value seen in x : xvals <- unique(x) xmaxindx <- length(x) - match(xvals,rev(x)) + 1L Rearrange xvals <- xvals[order(xmaxindx,decreasing=TRUE)] xmaxindx <-

This question already has an answer here: How to check if a program exists from a Bash script? 35 answers I've read in some bash FAQ a while ago (that I don't remember), that which should be avoided and command -v preferred. Why is that so? What are the advantages, disadvantages of either one? Well... command is likely built in to your shell, and with the -v option will tell you how your shell will invoke the command specified as its option. which is an external binary, located at /usr/bin/which which steps through the $PATH environment variable and checks for the existence of a file. A reason

Ideally, I would be able to use a program like find [file or directory name] to report the paths with matching filenames/directories. Unfortunately this seems to only check the current directory, not the entire folder. I've also tried locate and which, but none find the file, even though I know its on the computer somewhere. "Unfortunately this seems to only check the current directory, not the entire folder". Presumably you mean it doesn't look in subdirectories. To fix this, use find -name "filename" If the file in question is not in the current working directory, you can search your entire