Since the diagnostics often make use of the observation names of the data frame, you may find it helpful to specify observation names for the data input. Use the row.names command to achieve this. For example, to assign the names ``Dan'', ``Kosuke'', ``Liz'' and ``Gary'' to a data frame with the first four observations in the Lalonde data, type:
> test <- lalonde[1:4, ]
> row.names(test) <- c("Dan", "Kosuke", "Liz", "Gary")
> print(test)
age educ black hisp married nodegr re74 re75 re78 u74 u75 treat
Dan 37 11 1 0 1 1 0 0 9930 1 1 1
Kosuke 22 9 0 1 0 1 0 0 3596 1 1 1
Liz 30 12 1 0 0 0 0 0 24910 1 1 1
Gary 27 11 1 0 0 1 0 0 7506 1 1 1