Message-ID: <631112356.1529590.1311438317240.JavaMail.fmail@mwmweb024>
Date: 2011-07-23T16:25:17Z
From: Jens Oehlschlägel
Subject: 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?