df_poisson <- structure(list(V1 = c(131L, 38L, 19L, 96L, 13L, 34L),
    V2 = c(1L, 1L, 1L, 1L, 0L, 1L), V3 = c(104L,
    30L, 20L, 72L, 21L, 62L), V4 = c(20L, 12L, 7L,
    14L, 7L, 18L), V5 = c(38L, 9L, 12L, 31L, 10L, 18L), V6 = c(2L,
    0L, 1L, 2L, 0L, 7L), V7 = c(293L, 87L, 44L, 217L,
    46L, 156L), V8 = c(1L, 0L, 0L, 0L, 0L, 0L), V9 = c(0L,
    1L, 0L, 0L, 0L, 0L), V10 = c(1L, 1L, 1L, 0L, 0L,
    1L), V11 = c(1L, 1L, 1L, 1L, 1L, 1L), V11 = c(1L,
    1L, 1L, 1L, 0L, 1L), V13 = c(4L, 1L, 1L, 0L, 0L, 2L),
    V14 = c(0L, 0L, 0L, 0L, 0L, 0L), V15 = c(0L,
    0L, 0L, 0L, 0L, 0L), V16 = c(0L, 0L, 0L, 0L, 0L, 0L),
    V17 = c(0L, 0L, 0L, 0L, 0L, 0L)), .Names = c("V1",
"V2", "V3", "V4", "V5", "V6",
"V7", "V8", "V9", "V10", "V11",
"V12", "V13", "V14", "V15", "V16",
"V17"), row.names = c(NA, 6L), class = "data.frame")