exampleDataScatter <- function(){
  data.frame(
    subj = c(rep('subj1', 20), rep('subj2', 20)),
    time = rep( 1:20 , 2 ),
    response =  c(1:20, 50:31) + c(0.44, -1.99, -1.43, -1.95, -0.51,  0.66, -1.18,
                                   -2.01,  1.92,  2.86,  2.48, -2.41, 1.78, -2.54,
                                   2.11, -0.29,  0.67, -1.22,  1.31, 0.92, -0.40,
                                   -0.93, -0.62,  0.12, -0.08, -2.19,  1.74,  2.61,
                                   2.37,  1.70,  2.88,  1.32, -1.00,  0.66,
                                   1.26,  0.00,  2.77,  0.89, 0.54,  2.49),
    treat =  rep(c('trA', 'trB'), 20),
    stringsAsFactors = FALSE
  )
}