Well, no matter how many times you slice it, a pizza is always (mostly)
planar :-). The problem with map coloring occurs when you can't draw a
line on a plane from a fixed point on all features to a fixed point on
their adjacent features without the lines crossing. You have to lift the
lines off the plane to connect adjacent features, so the adjacency graph
becomes non-planar.
I've got a fix for it now, one that doesn't count features touching on a
point as adjacent. Give it a try -
https://sourceforge.net/projects/ojmapcoloring/files/0.5/
-lreeder
On Mon, Sep 22, 2014 at 4:09 AM, Rahkonen Jukka (Tike) <
jukka.rahko...@mmmtike.fi> wrote:
> Hi Larry,
>
>
>
> I should have actually guessed what happened. There used to be 8
> municipalies sharing a common landmark but because of some fusions there
> are only 6 left now.
>
> I tried to find a document that says that pizza is no more planar when it
> is sliced into 6 pieces. However, I found some documents which define the
> four or five color theorem so that polygons are considered to be adjacent
> if they share an edge, not only a point. This is one of those
> http://www.mathpages.com/home/kmath266/kmath266.htm.
>
>
>
>
>
> -Jukka-
>
>
>
>
>
> Larry Reeder wrote:
>
>
>
> Hey Jukka,
>
>
>
> Just got a chance to look at this. The region that is not coloring is
> interesting.
>
>
>
>
>
>
> It's like a pizza sliced into six pieces, each touching at the point.
> You can't color this portion of the map with only five colors without two
> adjacent (maybe just adjacent at one point in the enter) regions having the
> same color. In graph-theory terms, the graph is "non-planar" and can't be
> colored correctly with the five-color theorem. The map coloring plugin
> detects this and refuses to color this portion of the map.
>
>
>
> From a practical standpoint, you probably don't care that regions touching
> at a single point have the same color, as long as they don't share a color
> along a long edge. I'll look at updating the plugin to detect this and
> continue coloring.
>
>
>
> -lreeder
>
>
>
>
>
>
>
> On Mon, Sep 15, 2014 at 7:15 AM, Rahkonen Jukka (Tike) <
> jukka.rahko...@mmmtike.fi> wrote:
>
> Hi,
>
> I found a shapefile from which some polygons are not colored with the Map
> coloring plugin v. 0.4. Shapefile does not have topology errors but some
> multipolygons have quite a many parts because of archipelago. However,
> exploding multipolygons into polygons does not change the behaviour. The
> problematic shapefile can be found from
> http://latuviitta.org/downloads/ojmapcolor_error.zip
>
> Error appears always in the same place in South-West. For example features
> with OGR_FID=180 or 234 stays without color.
>
> -Jukka Rahkonen-
>
>
> ------------------------------------------------------------------------------
> Want excitement?
> Manually upgrade your production database.
> When you want reliability, choose Perforce
> Perforce version control. Predictably reliable.
>
> http://pubads.g.doubleclick.net/gampad/clk?id=157508191&iu=/4140/ostg.clktrk
> _______________________________________________
> Jump-pilot-devel mailing list
> Jump-pilot-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
>
>
>
>
> ------------------------------------------------------------------------------
> Meet PCI DSS 3.0 Compliance Requirements with EventLog Analyzer
> Achieve PCI DSS 3.0 Compliant Status with Out-of-the-box PCI DSS Reports
> Are you Audit-Ready for PCI DSS 3.0 Compliance? Download White paper
> Comply to PCI DSS 3.0 Requirement 10 and 11.5 with EventLog Analyzer
>
> http://pubads.g.doubleclick.net/gampad/clk?id=154622311&iu=/4140/ostg.clktrk
> _______________________________________________
> Jump-pilot-devel mailing list
> Jump-pilot-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
>
>
------------------------------------------------------------------------------
Meet PCI DSS 3.0 Compliance Requirements with EventLog Analyzer
Achieve PCI DSS 3.0 Compliant Status with Out-of-the-box PCI DSS Reports
Are you Audit-Ready for PCI DSS 3.0 Compliance? Download White paper
Comply to PCI DSS 3.0 Requirement 10 and 11.5 with EventLog Analyzer
http://pubads.g.doubleclick.net/gampad/clk?id=154622311&iu=/4140/ostg.clktrk
_______________________________________________
Jump-pilot-devel mailing list
Jump-pilot-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
