[R] warning message

[Shi, Tao]

Hi list,

Can somebody explain why there are these warning messages?  I just don't get it.  I'm using R 2.15.1 on WinXP.

Thanks!

Tao


> x
[1] -2.143510 -1.157450 -1.315581  1.033562 -1.225440 -1.179909

>  ifelse(x>0, log2(x), -log2(-x))
[1] -1.099975 -0.210950 -0.395700  0.047625 -0.293300 -0.238675
Warning messages:
1: In ifelse(x > 0, log2(x), -log2(-x)) : NaNs produced
2: In ifelse(x > 0, log2(x), -log2(-x)) : NaNs produced