Hi Gueyenono,
here are the data as suggested. thanks.
dput(bpdsample)
structure(list(bpd = structure(c(1L, 1L, 2L, 2L, 1L, 2L, 2L,
1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L,
1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 2L, 2L, 2L, 1L, 1L,
1L, 2L, 1L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 2L), .Label = c("0",
"1"), class = "factor"), birthwt = c(870, 1340, 850, 1420, 1250,
930, 1310, 1330, 1470, 1150, 1570, 1560, 700, 820, 1680, 1180,
520, 1650, 1170, 650, 1260, 1180, 1040, 1690, 1380, 1130, 730,
1400, 1670, 1530, 1550, 1350, 1520, 820, 1200, 820, 820, 1500,
1680, 990, 700, 1050, 1000, 870, 1320, 1380, 1550, 890, 1410,
1050), gestage = c(29, 30, 30, 30, 32, 28, 31, 30, 32, 32, 33,
36, 26, 28, 30, 32, 28, 33, 29, 26, 31, 30, 29, 33, 32, 30, 27,
29, 36, 31, 33, 31, 33, 29, 30, 26, 28, 30, 32, 30, 26, 28, 31,
28, 31, 33, 32, 27, 31, 29), toxemia = structure(c(1L, 2L, 1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L,
1L, 1L, 1L, 1L, 1L, 2L, 1L, 2L, 2L, 1L, 1L, 2L, 1L, 1L, 2L, 1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L), .Label = c("0",
"1"), class = "factor")), row.names = c("97", "155", "166", "99",
"148", "57", "45", "154", "24", "184", "76", "211", "10", "181",
"205", "199", "165", "158", "74", "81", "91", "70", "54", "32",
"147", "69", "35", "138", "84", "130", "159", "153", "168", "109",
"80", "163", "20", "95", "216", "221", "41", "144", "43", "161",
"92", "220", "68", "63", "12", "136"), class = "data.frame")