Re: Where is ShowGraph?

*To*: mathgroup at smc.vnet.net*Subject*: [mg125970] Re: Where is ShowGraph?*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Tue, 10 Apr 2012 02:30:13 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201204090932.FAA28441@smc.vnet.net>*Reply-to*: murray at math.umass.edu

First, you have the wrong syntax to obtain a Knight's tour graph. What you've obtained as result of GraphData["KnightsTour"] is not a single graph, but rather a list of all those Knight's Tour graphs that Mathematica has available. To get a particular one of these, use e.g., GraphData[{"KnightsTour", {2, 5}}] The output will be a visual representation of the graph. Second, not all of the Combinatorica add-on package functionality has been subsumed by built-in (i.e., Kernel-implemented) functions. If you want to use, e.g., ShowGraph -- which is strictly a Combinatorica package function and not a built-in kernel function, you have to load the package. Thus: <<Combinatorica` ShowGraph[CompleteGraph[5]] Unfortunately, the Mathematica developers seem not to have completely ported over from Combinatorica to the kernel _all_ the functionality in the former. So at times we're left with this awkward combination of using both the newer kernel functions and the older Combinatorica functions. And that can lead to a lot of confusion, not least the General::compat message you get when you load Combinatorica. On 4/9/12 5:32 AM, James Stein wrote: > I assume Combinatorica comes preloaded with Mathematica 8, because my > attempt to load Combinatorica gives an error message "Combinatorica Graph > and Permutations functionality has been superseded by preloaded > functionaliy[sic]." > > And indeed, so it seems, as this code works fine: > g = GraphData["KnightsTour"] > resulting in an apparently sensible list structure for g. > > However, online documentation for Combinatorica describes a routine > ShowGraph, giving this example: > ShowGraph[CompleteGraph[5]] > But ShowGraph is not defined (apparently not preloaded). Indeed, > 'ShowGraph' appears in blue text (undefined) in the aforementioned > documentation page. > > I visited www.combinatorica.com, as suggested by the documentation, without > edification. > > What am I missing? How do I display the graph 'g'? > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Where is ShowGraph?***From:*James Stein <mathgroup@stein.org>