computepair.R

system("ls -1F | grep '/$' > studentnames.txt");
folders = read.table('studentnames.txt');
folders = folders[[1]];
folders = as.character(folders);

randomize = sample(1:18,18,replace=FALSE)
folders = folders[randomize]

nfolders = length(folders)
for(itr.i in 1:(nfolders-1)) {
    for(itr.j in (itr.i+1):nfolders) {
        folder1 = folders[itr.i]
        folder2 = folders[itr.j]
        #sout = paste(folder1,'_vs_',folder2,'\n',sep='')
        #cat('\n$', sout,'')
        filename1 = paste(folder1,'my1rpack/R/problem1.R',sep='')
        filename2 = paste(folder2,'my1rpack/R/problem1.R',sep='')
        bashcmd = paste('diff ',filename1,' ',filename2,' ',sep='')
        output = system(bashcmd)
        cat('\n')
        bashcmd = paste('diff ',filename1,' ',filename2,' | wc -l >> result.txt',sep='')
        output = system(bashcmd)
        bashcmd = paste('wc -l ',filename1,sep='')
        output = system(bashcmd)
        bashcmd = paste('wc -l ',filename2,sep='')
        output = system(bashcmd)
        scan() #use CTRL-C to break out
    }
}

output = read.table('result.txt')
output = output[[1]]
result = matrix(0,nrow=nfolders,ncol=nfolders)

count = 0
for(itr.i in 1:(nfolders-1)) {
    for(itr.j in (itr.i+1):nfolders) {
        count = count + 1
        result[itr.i,itr.j] = output[count]
    }
}
result = result + t(result)

require(lattice)
graphics.off()
dev.new()
levelplot(result,main='Dissimilarity Matrix')
dev.new()
reduced = cmdscale(result)
plot(reduced)
xval = reduced[,1]+runif(18,-5,5)
yval = reduced[,2]+runif(18,-5,5)
text(xval.j,yval,1:18,cex=.5)