Hi James, Try
mat[, apply(mat, 2, function(x) any(diff(x) == 1))] HTH, Jorge.- On Fri, Aug 22, 2014 at 10:18 PM, James Wei <zwei0...@hotmail.com> wrote: > > > Hi all, > > I have a matrix with consecutive and non-consecutive numbers > in columns. For example, the first 2 columns have consecutive numbers. I > want R > to print only columns with consecutive numbers. Here is the matrix and how > I > did using conditional statement: > > ## > > mat=matrix(data=c(9,2,3,4,5,6,10,13,15,17,19,22, > 25,27,29,31,34,37,39,41),ncol=5) > > mat > > difference = diff(mat)==1 > > difference > > y1=difference[1,] > > y2=difference[2,] > > y3=difference[3,] > > y=(y1|y2|y3) > > y > > > > if (y=="TRUE") mat else 0 > > ## > > However, R still print all 5 columns, not the first 2 > columns I wanted. I got the Warning message: > > In if (y == "TRUE") mat else 0 : > > the condition has > length > 1 and only the first element will be used > > How can I change the code to get only the first 2 columns > with consecutive numbers printed? I am new to R. > > Thanks in advance for your help. James > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.