Re: [R] Data frame to Matrix by category

Thank you mate! -- View this message in context: http://r.789695.n4.nabble.com/Data-frame-to-Matrix-by-category-tp4669669p4669768.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/

Re: [R] Data frame to Matrix by category

Hello, Maybe something like the following. dat <- read.table(text = " isin dt 1 FR0109970386 2010-01-12 2 FR0109970386 2011-01-12 3 FR0109970386 2012-01-12 4 FR0116114978 2010-01-12 5 FR0116114978 2011-01-12 6 FR0116114978 2012-01-12 ", header = TRUE, stringsAsFactors = FALSE)

Re: [R] Data frame to matrix - revisited

Hi: Here are a couple of ways. Since your data frame does not contain a 'c' in ID2, we redefine the factor to give it all five levels rather than the observed four: > df <- read.table(textConnection(" + ID1 ID2 Value + a b 1 + b d 1 + c a 2 + c e 1 + d a 1 + e d 2"), header = TRUE) str(df) > str(

Re: [R] Data frame to matrix - revisited

Jagz, Assuming that your data frame is called df, try this ... tapply(df$Value, list(df$ID1, df$ID2), mean) Jean `·.,, ><(((º> `·.,, ><(((º> `·.,, ><(((º> Jean V. Adams Statistician U.S. Geological Survey Great Lakes Science Center 223 East Steinfest Road Antigo, WI 54409 USA 715-627-

Re: [R] data frame to matrix

My Coyne a écrit : > I have a data frame and would like to convert it into a matrix, how do I do > that? either use the df for the initialisation values mat = matrix(df, ...) or as.matrix() could do the trick. __ R-help@r-project.org mailing list https: