# HG changeset patch
# User Robert McIntyre <rlm@mit.edu>
# Date 1329065798 25200
# Node ID be78d7bd6920fa73c2de4107a6a934f7443d05af
# Parent  712bd7e5b148a368ce1224af4e858b3ea68e8527
fixed major bug in collapse

diff -r 712bd7e5b148 -r be78d7bd6920 org/ideas.org
--- a/org/ideas.org	Sun Feb 12 09:05:47 2012 -0700
+++ b/org/ideas.org	Sun Feb 12 09:56:38 2012 -0700
@@ -72,11 +72,12 @@
        -- day
  - [ ] create video showing all the senses for Winston -- 2 days
  - [ ] send package to friends for critiques -- 2 days
+ - [ ] fix videos that were encoded wrong, test on InterNet Explorer.
+ - [ ] redo videos vision with new collapse code
  - [ ] write summary of project for Winston            \
  - [ ] project proposals for Winston                    \
  - [ ] additional senses to be implemented for Winston   |  -- 2 days 
  - [ ] send Winston package                             /
- - [ ] fix videos that were encoded wrong, test on InterNet Explorer.
 
 ** would be cool to get done before winston
  - [X] enable greyscale bitmaps for touch -- 2 hours 
diff -r 712bd7e5b148 -r be78d7bd6920 org/sense.org
--- a/org/sense.org	Sun Feb 12 09:05:47 2012 -0700
+++ b/org/sense.org	Sun Feb 12 09:56:38 2012 -0700
@@ -165,11 +165,13 @@
 
 #+name: topology-2
 #+begin_src clojure
+(in-ns 'cortex.sense)
+
 (defn average [coll]
   (/ (reduce + coll) (count coll)))
 
-(defn collapse-1d
-  "One dimensional analogue of collapse."
+(defn- collapse-1d
+  "One dimensional helper for collapse."
   [center line]
   (let [length (count line)
         num-above (count (filter (partial < center) line))
@@ -178,8 +180,17 @@
            (+ center num-above))))
 
 (defn collapse
-  "Take a set of pairs of integers and collapse them into a
-   contigous bitmap with no \"holes\"."
+  "Take a sequence of pairs of integers and collapse them into a
+   contigous bitmap with no \"holes\" or negative entries, as close to
+   the origin [0 0] as the shape permits. The order of the points is
+   preserved.
+
+   eg.
+   (collapse [[-5  5] [5  5]    -->  [[0 1] [1 1] 
+              [-5 -5] [5 -5]])  -->   [0 0] [1 0]]
+
+   (collapse [[-5  5] [-5 -5]    -->  [[0 1] [0 0] 
+              [ 5 -5] [ 5  5]])  -->   [1 0] [1 1]]"
   [points]
   (if (empty? points) []
       (let
@@ -213,8 +224,13 @@
              (map (fn [[x y]]
                     [(- x min-x)
                      (- y min-y)])
-                  squeezed))]
-        relocated)))
+                  squeezed))
+           point-correspondance
+           (zipmap  (sort points) (sort relocated))
+
+           original-order
+           (vec (map point-correspondance points))]
+        original-order)))
 #+end_src
 * Viewing Sense Data