Thorsten Raff <t.raff <at> med2.uni-kiel.de> writes: > I have the problem that I want to transform a dataframe as generated by > > diagnosis <- rep(diagnosis[1:3], 3) > marker <- gl(3,3) > values <- rnorm(9) > dataframe <- cbind(diagnosis, marker, values) > dataframe <- dataframe[c(1:5, 7:9), ] > > into a matrix where levels(diagnosis) is indicating the rows of the matrix, > levels(marker) the columns and values are the actual content of the matrix. > However, as can been seen in the dataframe, some observations are missing and > should result in <NAs> in the resulting matrix, giving a result like this: > > marker 1 2 3 > diagnosis1 value value value > diagnosis2 value value value > diagnosis3 value NA value >
You can make your examples self-running by providing fake data for diagnosis, e.g. using letters[] instead of diagnosis. In addition, note that your cbind has an awkward side effect by converting everything to character as the least common denominator for the variables in a matrix. For real work, use reshape with its frightening number of parameters. If you don't understand that function at the seventh reading, stay cool: it's not your fault. You might also try package reshape, but it is not much easier for occasional use. Dieter # diagnosis <- as.factor(rep(letters[1:3], 3)) marker <- as.factor(gl(3,3)) values <- rnorm(9) dataframe <- data.frame(diagnosis=diagnosis, marker=marker, values=values) dataframe <- dataframe[c(1:5, 7:9), ] reshape(dataframe,idvar="diagnosis",direction="wide",timevar="marker") ______________________________________________ R-help@r-project.org mailing list 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.
