Hi
Gabor Grothendieck wrote:
Thanks. Yet one other comment to consider when thinking
about this. Even if its not possible
or advisable to guarantee order, even without the hash=
idea, it may be possible to guarantee that default names
are generated in some order that can be used by
getChildren to ensure that it returns the children in
the same order they are created or perhaps even some sort
of timestamp can be attached to objects to facilitate
later traversal.
Thanks Gabor. I will look at a way to ensure that childNames(vpTree)
returns the names in the order that they were pushed. This may be as
simple as porting the mechanism used for grobs and gTrees, where
(drawing) order is very important.
Paul
On 6/7/05, Paul Murrell <[EMAIL PROTECTED]> wrote:
Hi
Gabor Grothendieck wrote:
Here is the code once again. This time I have supplied two
names methods and a getChildren.viewport function to
encapsulate the corresponding grid internals. It would
be easiest if grid provided these itself but in the absence
of that this does encapsulate dependencies on grid
internals to a well defined set of functions. Note that
names is only used in 'with' and 'with' will be eliminated
once Deepayan adds the use.viewport= (or whatever
its called) to print. I am not sure from your response
whether or not you intend to add these items to the grid
API but in any case this provides an intermediate
level of safety.
Yep, I've made a note to look at adding these to the grid API.
Thanks.
Paul
library(grid)
library(lattice)
pushLayout <- function(nr, nc, name="layout") {
pushViewport(viewport(layout=grid.layout(nr, nc), name=name))
for (i in 1:nr) {
for (j in 1:nc) {
pushViewport(viewport(layout.pos.row=i, layout.pos.col=j))
upViewport()
}
}
upViewport()
}
names.vpPath <- names.viewport <- function(x) x$name
with.vpPath <- with.viewport <- function(data, expr, ...) {
# if data is a vpPath it cannot be ROOT since
# NULL will never dispatch here
depth <- if (data$name == "ROOT") 0 else downViewport(names(data))
result <- eval.parent(substitute(expr))
upViewport(depth)
invisible(result)
}
getChildren.viewport <- function(x) x$children
grid.newpage()
# specify number of cells to fill and number of rows
n <- 5; nr <- 3
nc <- ceiling(n/nr)
downViewport(pushLayout(nr, nc))
vpt <- current.vpTree(all = FALSE)
for(k in 1:n) with(getChildren.viewport(vpt)[[k]],
print( xyplot(v ~ v, list(v = 1:k)), newpage = FALSE )
)
--
Dr Paul Murrell
Department of Statistics
The University of Auckland
Private Bag 92019
Auckland
New Zealand
64 9 3737599 x85392
[EMAIL PROTECTED]
http://www.stat.auckland.ac.nz/~paul/
--
Dr Paul Murrell
Department of Statistics
The University of Auckland
Private Bag 92019
Auckland
New Zealand
64 9 3737599 x85392
[EMAIL PROTECTED]
http://www.stat.auckland.ac.nz/~paul/
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