Jimmy,
I tried to perform your steps on the day 6 part a sample data, but must be
doing something wrong because I get 23 vectors in the final step, which
means that 23 areas can be eliminated, but according to my other analysis,
that eliminates too many (infinite) areas. According to my work, the 10th
area of 3890 was largest corresponding to 149,172 .
_50]\5!:5 <'data6a'
50 2$81 157 209 355 111 78 179 211 224 268 93 268
237 120 345 203 72 189 298 265 190 67 319 233 328
40 323 292 125 187 343 186 46 331 106 350 247 332
349 145 217 329 48 177 105 170 257 166 225 113 44
98 358 92 251 209 206 215 115 283 206 195 144 157
246 302 306 157 185 353 117 344 251 155 160 48 119
131 343 349 223 291 256 89 133 96 240 271 322 73
324 56 149 272 161 107 172 171 301 291
coordinates=. (4 $. $.)@:$&1
notborder =. ,/(<({.each@{.}.each i.each@{:)@(<./,:>./) data6a){
($coordinates) 359 359
border =. notborder -.~ coordinates 359 359
$distance =: +/"1|data6a-"1"1 2 border
50 29971
$min=:(<./distance) ="1 distance
50 29971
$I. +./"1 (1=+/min)#"1 min
23
I. +./"1 (1=+/min)#"1 min
1 2 5 7 9 10 11 12 13 15 16 17 18 19 21 25 26 34 35 37 39 41 45
On Sun, Dec 9, 2018 at 7:59 PM Jimmy Gauvin <[email protected]> wrote:
> Hi,
>
> The method I used to determine the infinite vertices is very close to
> David's approach.
> The main difference is to drop the border points that are equidistant to 2
> or more input points.
>
> - calculate the coordinates of all border points (all points just
> outside the minimum and maximum of input coordinates)
>
> - calculate the distance between all border points and input coordinates
> input and border are n by 2 matrices
> distance =: +/"1|input-"1"1 2 border
>
> - tag the input points that are a minimum distance to each border
> coordinate
> min=:(<./distance) ="1 distance
>
> - keep border points that correspond to only one input point
> min=: (1=+/min)#"1 min
>
> - list infinite vertices
> I. +./"1 min
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
--
(B=) <-----my sig
Brian Schott
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
