local average
Hi, cut() and tapply() are your friends: tapply(Y, cut(X, 0:100, include.lowest=TRUE), mean) To compute medians, just pass median to tapply(). You will get NAs where no data is found in any bin. Cheers, Rich
On 4/21/05, Jens Hainmueller <jens_hainmueller at ksg05.harvard.edu> wrote:
Hello, probably this isn't hard, but I can't get R to do this. Thanks for your help! Assume I have a matrix of two covariates: n <- 1000 Y <- runif(n) X <- runif(n,min=0,max=100) data <- cbind(Y,X) Now, I would like to compute the local average of Y for each X interval 0-1, 1-2, 2-3, ... 99-100. In other words, I would like to obtain 100 (local) Ybars, one for each X interval with width 1. Also, I would like to do the same but instead of local means of Y obtain local medians of Y for each X interval. Best, Jens
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Rich FitzJohn rich.fitzjohn <at> gmail.com | http://homepages.paradise.net.nz/richa183 You are in a maze of twisty little functions, all alike