+par(mfrow = c(1,K),oma = c(0,0,3,0))
+mtext("Regression matrices in each cluster", side=3, line=4, font=2, cex=2, col='red')
+
+par(mfrow = c(1,2), oma=c(0,0,3,0))
+for (i in 1:4)
+ plot(runif(20), runif(20),
+ main=paste("random plot (",i,")",sep=''))
+par(op)
+mtext("Four plots",
+ side=3, line=4, font=2, cex=2, col='red')