how to display a simplified graph of commits ?

Hi list,

I'd like to know if the following is possible and, if not, I'd like to suggest it as a possible useful addition to the git frontend/graphical tools: display a simplified graph of "interesting" commits showing the relationship between a specified set of commits.

In other words, I have a set of revisions that I'm interested in, and I'd like to graphically display the relationships (merges, branches) between them, omitting the cruft of intervening irrelevant commits.

A possible mathematical definition of what I'd like would be this: given a finite set S of commits, consider the subgraph G (of the full commit graph) consisting of the union of all possible paths leading from a latest-common-ancestor of any subset of S to an earliest-common-descendant; define a commit to be "interesting" (wrt S) when it has more than one ancestor or more than one child _in the subraph G_ (i.e., it is either a branch or a merge point in the subgraph), or, of course, when it itself in S; I'd like to display the subgraph G by displaying all its interesting commits and the sequences of edges between them (but not all the intermediate commits).

(The above, of course, is just one example of a rigorous definition of what an "interesting" commit might be. There may be others, and obviously I don't care about using exactly that one.)

The point is that I want to understand the code flow among branches containing certain revisions in a git tree, and who merged what--and there are too many intermediate commits to make anything useful of the standard display of gitk. Restricting a view to a certain subset of the files helps a lot, but it is still not sufficient as it is neither true that every commit I'm interested in touches this or that subset of the files, nor the converse.

Is there another way I can restrict the set of commits to display, with any kind of graphical tool like gitk?