Find mean of values in three-dimensional array
On 15 Jun 2016, at 19:37 , Nick Tulli <nick.tulli.95 at gmail.com> wrote: Hey R-Help, I've got a three dimensional array which I pulled from a netcdf file. The data in array are the humidity values of locations in the United States over a time period. The three dimensions are [longitude, latitude, days], 141x81x92. My goal is to find the mean value at each longitude/latitude over the 92 day period. I could probably accomplish my goal by running a loop, but I'm sure that there is a much easier and more efficient way to accomplish the goal in R. Any suggestions?
Dunno about fast, but the canonical way is apply(A, c(1,2), mean) E.g. (A <- array(1:24,c(2,3,4))) apply(A, c(1,2), mean) apply(A, c(1,3), mean) -pd
Thanks guys.
______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23 Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com