[Rd] [R] lattice: levelplot: error: min not meaningful for factor (PR#6005)

[wolfram at fischer-zim.ch]

R 1.8.1:

___COMMAND____________________________________________

levelplot( yield ~ year * variety | site, barley )


___ERROR_MESSAGE______________________________________

Error in Summary.factor(..., na.rm = na.rm) : 
        "min" not meaningful for factors

___COMMENT____________________________________________

levelplot( yield ~ as.numeric(year) * as.numeric(variety) | site, barley )
is working but the labels are nasty.

Best regards
Wolfram