Nothing
#
# Copyright (c) 2014, Stephen B. Weston
#
# This is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as published
# by the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
# USA
imerge <- function(...) {
heapify <- function(node, max) {
if (max > 0) {
repeat {
lchild <- 2L * node
rchild <- 2L * node + 1L
i <- if (lchild <= max && h[[lchild]]$val < h[[node]]$val)
lchild
else
node
if (rchild <= max && h[[rchild]]$val < h[[i]]$val)
i <- rchild
if (i == node)
break
tmp <- h[[node]]
h[[node]] <<- h[[i]]
h[[i]] <<- tmp
node <- i
}
}
}
its <- lapply(list(...), iter)
h <- vector('list', length(its))
n <- 0L
for (it in its) {
tryCatch({
h[[n + 1L]] <- list(val=nextElem(it), it=it)
n <- n + 1L
},
error=function(e) {
# Skip any iterators that don't have any values
if (!identical(conditionMessage(e), 'StopIteration'))
stop(e)
})
}
# Convert "h" into a heap
i <- n %/% 2L
while (i > 0L) {
heapify(i, n)
i <- i - 1L
}
nextEl <- function() {
if (n == 0) {
stop('StopIteration', call.=FALSE)
} else {
val <- h[[1]]$val
tryCatch({
h[[1]]$val <<- nextElem(h[[1]]$it)
heapify(1L, n)
},
error=function(e) {
if (!identical(conditionMessage(e), 'StopIteration'))
stop(e)
h[[1]] <<- h[[n]]
n <<- n - 1L
heapify(1L, n)
})
val
}
}
object <- list(nextElem=nextEl)
class(object) <- c('abstractiter', 'iter')
object
}
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.