Description Usage Arguments Value Note Author(s) See Also Examples
Yet another assignment interface in order to allow to formulate x[index,...,add=TRUE]<-value
in a way which works transparently, not only for ff, but also for ram objects: add(x, value, index, ...)
.
1 2 3 4 5 |
x |
an ff or ram object |
value |
the amount to increment, possibly recylcled |
... |
further arguments – especially index information – passed to |
invisible()
Note that add.default
changes the object in its parent frame and thus violates R's usual functional programming logic.
Duplicated index positions should be avoided, because ff and ram objects behave differently:
1 2 3 4 5 | add.ff(x, 1, c(3,3))
# will increment x at position 3 TWICE by 1, while
add.default(x, 1, c(3,3))
# will increment x at position 3 just ONCE by 1
|
Jens Oehlschl<c3><a4>gel
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | message("incrementing parts of a vector")
x <- ff(0, length=12)
y <- rep(0, 12)
add(x, 1, 1:6)
add(y, 1, 1:6)
x
y
message("incrementing parts of a matrix")
x <- ff(0, dim=3:4)
y <- array(0, dim=3:4)
add(x, 1, 1:2, 1:2)
add(y, 1, 1:2, 1:2)
x
y
message("BEWARE that ff and ram methods differ in treatment of duplicated index positions")
add(x, 1, c(3,3))
add(y, 1, c(3,3))
x
y
rm(x); gc()
|
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