Constructing zenpaths and tools for extracting,
connecting and displaying pairs, as well as
grouping and indexing data structures.
zenpath(x, pairs = NULL,
method = c("front.loaded", "back.loaded",
"balanced", "eulerian.cross",
"greedy.weighted", "strictly.weighted"),
decreasing = TRUE)
Arguments
x 
method

pairs 
a twocolumn matrix containing (rowwise)
the pairs of connected variables to be sorted according to the
weights. The pairs argument is only used for the method s
greedy.weighted and strictly.weighted and can be
NULL (in which case a default is constructed in lexicographical order). 
method 
character string indicating the sorting
method to be used. Available methods are:
"front.loaded" :Sort all pairs such that the first variables appear
the most frequently early in the sequence;
an Eulerian path; note that it might be slightly
longer than the number of pairs because, first, an even
graph has to be made.
"back.loaded" :Sort all pairs such that the later variables appear
the most frequently later in the sequence;
an Eulerian path (+ see front.loaded concerning length)
"balanced" :Sort all pairs such that all variables appear in
balanced blocks throughout the sequence
(a Hamiltonian Decomposition; Eulerian, too).
"eulerian.cross" :Generate a sequence of pairs such that
each is formed with one variable from each group.
"greedy.weighted" :Sort all pairs according to a greedy (heuristic)
Euler path with x as weights visiting each
edge precisely once.
"strictly.weighted" :Strictly respect the order of the weights  so the first, second,
third, and so on, adjacent pair of numbers of the output of
zenpath() corresponds to the pair with largest,
secondlargest, thirdlargest, and so on, weight.

decreasing 
A logical indicating whether the
sorting is done according to increasing or decreasing weights. 
Value
Returns a sequence of variables (indices or names,
possibly a list of such), which can then be used to index the data
(via groupData()
for plotting via zenplot()
.
See also
Examples
## Some calls of zenpath()
zenpath(10) # integer argument
#> [1] 1 2 3 1 4 2 5 1 6 2 7 1 8 2 9 1 10 2 3 4 5 3 6 4 7
#> [26] 3 8 4 9 3 10 4 5 6 7 5 8 6 9 5 10 6 7 8 9 7 10 8 9 10
#> [1] 1 4 2 5 1 6 2 7 1 8 3 4 3 6 7 3 5 8 2