On Jun 3, 2011, at 7:20 PM, lana wrote:
Hi,
I have tried numerous methods and packages, but thus far cannot
seem to
find a solution. I am looking to essentially draw a filled colored
shape
around subsets on my data points on a scatter plot where none of the
shapes
overlap but instead bend around each other if necessary. I finally
came up
with the following steps which approximate what I am looking for,
but I am
completely lost as to how to implement several of the steps. The
steps are
listed below, along with a pictorial representation of what I am
hoping they
will achieve. Any suggestions would be greatly appreciated.
Are you trying to reinvent the wheel? A typical test for clustering
algorithms that attempt to find non-convex clusters (ones that "bend
around") is the rFace function. Searching with the engine used to
support the RSiteSearch function finds 17 R functions in various
packages that use it in their examples:
http://search.r-project.org/cgi-bin/namazu.cgi?query=rFace&max=100&result=normal&sort=score&idxname=functions
--
David.
1. Draw a circle of a give radius around each data point
radius can be the same for each point, or can be determined by a
vector of
values either the same length of the number of points or is repeated
until
all points are assigned
2. Begin with the area of greatest overlap between two circles, draw
a line
segment between the two intersection points and assign either side
of that
line to its respective shape
3. Repeat with largest remaining area of overlap. If a previous
division has
left an intersection point within the new area of overlap, such that
there
are now two possible points to attach the line segment to, use the
one from
which a division has already been drawn (so that three shapes now come
together in a point)
4. Repeat with successively smaller areas of overlap until no remain
5. Fill each resulting shape with a color determined by an outside
vector
associated with the points
6. (if possible) calculate the area of each resultant shape
http://r.789695.n4.nabble.com/file/n3572306/diagram_circles_coloring_3.png
http://r.789695.n4.nabble.com/file/n3572306/circle_interactions_3.png
--
View this message in context:
http://r.789695.n4.nabble.com/outlining-data-points-tp3572306p3572306.html
Sent from the R help mailing list archive at Nabble.com.
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David Winsemius, MD
West Hartford, CT
______________________________________________
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and provide commented, minimal, self-contained, reproducible code.
