Test whether an ff or ffdf object or a ff_pointer is opened.
Usage
is.open(x, ...)
## S3 method for class 'ff'
is.open(x, ...)
## S3 method for class 'ffdf'
is.open(x, ...)
## S3 method for class 'ff_pointer'
is.open(x, ...)
Arguments
x
an ff or ffdf object
...
further arguments (not used)
Details
ff objects open automatically if accessed while closed.
For ffdf objects we test all of their physical components including their row.names if they are is.ff
Value
TRUE or FALSE (or NA if not all components of an ffdf object are opened or closed)
Author(s)
Jens Oehlschl<c3><a4>gel
See Also
is.readonly, open.ff, close.ff
Examples
x <- ff(1:12)
is.open(x)
close(x)
is.open(x)
rm(x); gc()