Re: [R] Take the maximum of every 12 columns

Dear Henrik, This is great - thank you so much! Sincerely, Milu On Tue, Feb 20, 2018 at 10:12 PM, Henrik Bengtsson < henrik.bengts...@gmail.com> wrote: > It looks like OP uses a data.frame, so in order to use matrixStats > (I'm the author) one would have to pay the price to coerce to a matrix

Re: [R] Take the maximum of every 12 columns

It looks like OP uses a data.frame, so in order to use matrixStats (I'm the author) one would have to pay the price to coerce to a matrix before using matrixStats::rowMaxs(). However, if it is that the original data could equally well live in a matrix, then matrixStats should be computational effi

Re: [R] Take the maximum of every 12 columns

On Tue, Feb 20, 2018 at 11:58 AM, Bert Gunter wrote: > Ista, et. al: efficiency? > (Note: I needed to correct my previous post: do.call() is required for > pmax() over the data frame) > > > x <- data.frame(matrix(runif(12e6), ncol=12)) > > > system.time(r1 <- do.call(pmax,x)) >user system el

Re: [R] Take the maximum of every 12 columns

Sorry, previous code should be: > x <- data.frame(matrix(runif(12e6), ncol=12)) > system.time(r1 <- do.call(pmax,x)) user system elapsed 0.049 0.000 0.049 > system.time(r2 <- apply(x,1,max)) user system elapsed 2.162 0.045 2.207 > identical(r1,r2) [1] TRUE Bert Gunter "The

Re: [R] Take the maximum of every 12 columns

Ista, et. al: efficiency? (Note: I needed to correct my previous post: do.call() is required for pmax() over the data frame) > x <- data.frame(matrix(runif(12e6), ncol=12)) > system.time(r1 <- do.call(pmax,x)) user system elapsed 0.049 0.000 0.049 > identical(r1,r2) [1] FALSE > system.

Re: [R] Take the maximum of every 12 columns

This is what I was looking for. Thank you everyone! Sincerely, Milu Mail priva di virus. www.avast.com

Re: [R] Take the maximum of every 12 columns

Do you want the max of all the data in all 12 columns -- 1 number -- or the parallel max of the 12 columns -- a vector of length the number of rows. In the first case, max(df[,1:12]) will do (R uses 1-based indexing,not 0-based) ; in the second case, pmax(df[, 1:12]) will do. If either of these

Re: [R] Take the maximum of every 12 columns

Hi Milu, byapply(df, 12, function(x) apply(x, 1, max)) You might also be interested in the matrixStats package. Best, Ista On Tue, Feb 20, 2018 at 9:55 AM, Miluji Sb wrote: > Dear all, > > I have monthly data in wide format, I am only providing data (at the bottom > of the email) for the firs

Re: [R] Take the maximum of every 12 columns

Thank you for your kind replies. Maybe I was not clear with my question (I apologize) or I did not understand... I would like to take the max for X0...X11 and X12...X24 in my dataset. When I use pmax with the function byapply as in byapply(df, 12, pmax) I get back a list which I cannot convert t

Re: [R] Take the maximum of every 12 columns

Don't do this (sorry Thierry)! max() already does this -- see ?max > x <- data.frame(a =rnorm(10), b = rnorm(10)) > max(x) [1] 1.799644 > max(sapply(x,max)) [1] 1.799644 Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into i

Re: [R] Take the maximum of every 12 columns

The maximum over twelve columns is the maximum of the twelve maxima of each of the columns. single_col_max <- apply(x, 2, max) twelve_col_max <- apply( matrix(single_col_max, nrow = 12), 2, max ) ir. Thierry Onkelinx Statisticus / Statistician Vlaamse Overheid / Government of Flanders INST

Re: [R] Take the maximum of every 12 columns

?pmax Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Tue, Feb 20, 2018 at 6:55 AM, Miluji Sb wrote: > Dear all, > > I have monthly data in wide

[R] Take the maximum of every 12 columns

Dear all, I have monthly data in wide format, I am only providing data (at the bottom of the email) for the first 24 columns but I have 2880 columns in total. I would like to take max of every 12 columns. I have taken the mean of every 12 columns with the following code: byapply <- function(x,