Oops, I mistakenly said the array I viewmat'ed contained minimum distances, but it contained numbers between 1 and 50 signaling the index of each grid point's minimum-distance given vertex.
On Sat, Dec 8, 2018 at 10:34 AM Brian Schott <[email protected]> wrote: > I had quite a time doing day6 because after I computed all of the > distances for all the areas for each given vertex, I could not eliminate > the infinite vertices mathematically. For the 6-vertex the removal of > infinite vertices was simply a matter of finding the convex hull using > transitive closure, and then removing those vertices. But in the real data > set, that was not enough. From reading a comment on reddit.com (link > below) I gathered that one way to have found the set of all infinite areas > would have been to give the total area a large border so that the infinite > areas seemed infinite because of their disproportionately large area. > > https://www.reddit.com/r/adventofcode/comments/a3kr4r/2018_day_6_solutions/ > > But I did not try that because I discovered how to use viewmat to see the > 50+ areas and to use j's Amend on the array of minimum distances to > superimpose selective vertices as dots on the viewmat. Then I could see > (most of the areas -- not all of them because the color differentials were > not very contrasty for my color-defective eyes) the areas and visually > chase down the largest area. > > The viewmat approach mesmerized me a little, to be honest, but I am > wondering if another more mathematical approach could be used? I would be > happy to share my existing code, if that would be a better place to start. > But perhaps my description of my and your approach would be adequate. > > > Thanks, > > -- > (B=) <-----my sig > Brian Schott > -- (B=) <-----my sig Brian Schott ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
