Hello All, I'm trying to create a matrix from a dataframe (let's call it df): ......a......b.....c.....d a inputs output b inputs output c inputs output d inputs output e inputs output
The inputs are represented by columns a and b The outputs are represented by columns c and d, but the only outputs are those from column d - some values from column d are NA - column d was created with the code: df$d=rank(df$c, na.last="keep") #----------R Code---------# item=unique(df$a) n=length(list) r=matrix(data=NA,nrow=n, ncol=n, dimnames=list(PRR1=item, PRR2=item)) for(j in 2:ln) { for(i in 1:(j-1)) { input1=rownames(r)[i] input2=colnames(r)[j] q=df[(df$a==input1 & df$b==input2), "d"] if(length(q)==0) { q=df[(df$a==input2 & df$b==input1), "d"] } if(length(q)==0) { q=NA } r[j,i]=q r[i,j]=q r[j,j]=q } } The result is a matrix with the appropriate dimensions, but everything is filled with NA instead of the rankings of the various combinations. I'd like for the matrix to be filled with the ranking values--what have I done wrong? -- Best, Dat Mai PhD Rotation Student Albert Einstein College of Medicine [[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.