I have recently started working with microarray datasets and am trying to get my hands on R. I wish to make some plots out of my result data, but however I am stuck at the following. I have the following data (myData), cpg samp1 samp2 samp3 cpg1 0.43 0.32 0.21 cpg2 0.43 0.22 1.00 cpg3 0.11 0.99 0.78 cpg4 0.65 0.32 0.12 cpg5 0.11 0.43 0.89 And I wish to obtain a density plot for this, I did the following, plot (density(MyData$samp1), col="red") lines (density(MyData$samp2), col="green") lines (density(MyData$samp3), col="blue") But doing this does not give me correct plots, because not all sample curves fit within the plot limits. I did try looking for answers, but honestly i am still not able to work this out. Can you help me know how do i set my scale for the above? Or what additional should I do to the above code, so that all the curves are in range?? I have got many samples, so i need a something that could also automatically assign a different colour curve for each of my sample, after scaling it right. Thanks in advance..