Hi,
?qt says:
ncp: non-centrality parameter delta; currently for 'pt()' and
'dt()', only for 'ncp <= 37.62'.
'pt' doesn't complain when I give ncp > 37.62 (pnt.c seems to have a
workaround), but there is a discontinuity:
cbind(30:40, dt(10, df = 10, ncp = 30:40, log = T))
[,1] [,2] [1,] 30 -27.74986 [2,] 31 -30.98710 [3,] 32 -35.62105 [4,] 33 -41.85932 [5,] 34 -49.76884 [6,] 35 -59.35573 [7,] 36 -70.60410 [8,] 37 -83.48987 [9,] 38 -65.33569 [10,] 39 -69.99854 [11,] 40 -74.82708 In my usage there are many values of 'ncp', a small but positive fraction of which are greater than 37.62. Any suggestions about how I should handle it? Deepayan -- http://www.stat.wisc.edu/~deepayan/