[R] logical(0) response from lrm

[Rob James]

What causes the error report:

logical(0)

to arise in the rms function lrm?

Here's my data:

But both the dependent and the independent variable seem fine...

 > str(AABB)
'data.frame':    1176425 obs. of  9 variables:
  $ sex     : int  1 1 0 1 1 0 0 0 0 0 ...
$ faint   : int  0 0 0 0 0 0 0 0 0 0 ...

Here's the simplified model and error

AABB$model1 < lrm (faint ~  sex)
logical(0)


But the data seem fine....

 > table(AABB$faint)

       0       1
1173475    2950
 > table(AABB$sex)

      0      1
502551 673874

Suggestions?