ff package - Error selecting 0 rows.

Hi Ivan,

Thanks for reporting this bug.

Error in as.integer.hi(x, ...) : object 'ret' not found

debug(as.integer.hi) and calling again shows that the return value 'integer()' was not assigned to 'ret'. This is fixed now in subversion on r-forge and will find its way to CRAN during the next week.

Also, there doesn't seem to be a consistent way to return a data.frame with zero rows i.e. d[0,] returns a ffdf whereas d[1,] returns a data.frame

The documentation says "ff index expressions do not allow zeros and NAs" and trying to use a zero integer subscript?reminds you

c[0,]

Fehler in as.hi.integer(as.integer(x), ...) :
? 0s and mixed positive/negative subscripts not allowed

ff allows to use 'integer()' as an integer representation of an empty subscript, look at

c[integer(),]

[1] a b
<0 Zeilen> (oder row.names mit L?nge 0)

str(c[integer(),])

'data.frame':?? 0 obs. of? 2 variables:
?$ a: int
?$ b: int


Kind regards


Jens Oehlschl?gel?