Hi All, I am trying to apply MDS for 4 groups in my data. The groups are: groups = list( Day1C=c(9), Day1T=c(7,8,10), Day2C=c(1,2,3,6,11,13,14,15), Day2T=c(4,5,12,16,17,18) ) When I do the MDS plot the group1 member appears twice instead of one time in the plot. I don't know why this is happening. I would greatly appreciate your help in fixing this problem. Thanks in Advance. Ezhil