--- a/python/moving.py	Tue Aug 12 15:33:03 2014 -0400
+++ b/python/moving.py	Tue Aug 12 17:47:16 2014 -0400
@@ -179,8 +179,12 @@
 
     def __neg__(self):
         return Point(-self.x, -self.y)
+    
+    def orthogonal(self):
+        return Point(self.y, -self.x)
 
     def multiply(self, alpha):
+        'Warning, returns a new Point'
         return Point(self.x*alpha, self.y*alpha)
 
     def plot(self, options = 'o', **kwargs):
@@ -244,6 +248,10 @@
         return (counter%2 == 1);
 
     @staticmethod
+    def fromList(p):
+        return Point(p[0], p[1])
+
+    @staticmethod
     def dot(p1, p2):
         'Scalar product'
         return p1.x*p2.x+p1.y*p2.y
@@ -362,7 +370,7 @@
         import pdb; pdb.set_trace()  
     return X,Y
 
-def getSYfromXY(qx, qy, splines, spline_assumption_threshold=0.5, mode=0):
+def getSYfromXY(qx, qy, splines, goodEnoughSplineDistance = 0.5):
     ''' Snap a point (coordinates qx, qy) to it's nearest subsegment of it's nearest spline (from the list splines).
         
         To force snapping to a single spline, pass the spline alone through splines (e.g. splines=[splines[splineNum]]).
@@ -381,48 +389,37 @@
     #(buckle in, it gets ugly from here on out)
     ss_spline_d = subsec_spline_dist(splines)
     
-    temp_dist_min = float('inf')
+    minOffsetY = float('inf')
     #For each spline
     for spline in range(len(splines)):
         #For each spline point
-        for spline_p in range(len(splines[spline])):
-            if(spline_p > (len(splines[spline]) - 2)):
-                break
-            #Get point-intersection distance 
+        for spline_p in range(len(splines[spline])-1):
+            #Get closest point on spline
             X,Y = ppldb2p(qx,qy,splines[spline][spline_p][0],splines[spline][spline_p][1],splines[spline][spline_p+1][0],splines[spline][spline_p+1][1])
-            if(X == False and Y == False):
+            if X == False and Y == False:
                 print('Error: Spline {0}, segment {1} has identical bounds and therefore is not a vector. Projection cannot continue.'.format(spline, spline_p))
-                return [False,False,False,False,False,False,False]
-            #Check to see if point is not contained by subspline
-            if ss_spline_d[spline][0][spline_p]*1.05 < max(utils.pointDistanceL2(splines[spline][spline_p][0],splines[spline][spline_p][1],X,Y),utils.pointDistanceL2(splines[spline][spline_p+1][0],splines[spline][spline_p+1][1],X,Y)): continue          
-            
-            #Ok
-            temp_dist = utils.pointDistanceL2(qx,qy,X,Y)
-            if(temp_dist < temp_dist_min):
-                temp_dist_min             = temp_dist
-                snappedSpline             = spline
-                snappedSplineLeadingPoint = spline_p
-                snapped_x                 = X
-                snapped_y                 = Y
-            #Jump loop if significantly close
-            if(temp_dist < spline_assumption_threshold): break
-
-    try:
-        #Get sub-segment distance
-        subsegmentDistance = utils.pointDistanceL2(splines[snappedSpline][snappedSplineLeadingPoint][0],splines[snappedSpline][snappedSplineLeadingPoint][1],snapped_x,snapped_y)
-        #Get total segment distance
-        splineDistanceS = ss_spline_d[snappedSpline][1][snappedSplineLeadingPoint] + subsegmentDistance
-        #Get offset distance    
-        offsetY = utils.pointDistanceL2(qx,qy, snapped_x,snapped_y) 
-        
-        if(mode):        
-            direction = getOrientation([splines[snappedSpline][snappedSplineLeadingPoint][0],splines[snappedSpline][snappedSplineLeadingPoint][1]] , [splines[snappedSpline][snappedSplineLeadingPoint+1][0],splines[snappedSpline][snappedSplineLeadingPoint+1][1]] , [qx,qy])       
-            if(direction == 'left'): offsetY = -offsetY       
-        
-        return [snappedSpline, snappedSplineLeadingPoint, snapped_x, snapped_y, subsegmentDistance, splineDistanceS, offsetY]
-    except:
-        return [False,False,False,False,False,False,False]
-    
+                return None
+            if utils.inBetween(splines[spline][spline_p][0], splines[spline][spline_p+1][0], X) and utils.inBetween(splines[spline][spline_p][1], splines[spline][spline_p+1][1], Y): 
+                offsetY = utils.pointDistanceL2(qx,qy,X,Y)
+                if offsetY < minOffsetY:
+                    minOffsetY = offsetY
+                    snappedSpline = spline
+                    snappedSplineLeadingPoint = spline_p
+                    snapped_x = X
+                    snapped_y = Y
+                #Jump loop if significantly close
+                if offsetY < goodEnoughSplineDistance: 
+                    break
+    #Get sub-segment distance
+    subsegmentDistance = utils.pointDistanceL2(splines[snappedSpline][snappedSplineLeadingPoint][0],splines[snappedSpline][snappedSplineLeadingPoint][1],snapped_x,snapped_y)
+    #Get total segment distance
+    splineDistanceS = ss_spline_d[snappedSpline][1][snappedSplineLeadingPoint] + subsegmentDistance
+    orthogonalSplineVector = Point(splines[snappedSpline][snappedSplineLeadingPoint+1][1]-splines[snappedSpline][snappedSplineLeadingPoint][1],
+                                   splines[snappedSpline][snappedSplineLeadingPoint][0]-splines[snappedSpline][snappedSplineLeadingPoint+1][0])#positive orthogonal vector of vector (x,y) is (y, -x)
+    offsetVector = Point(qx-snapped_x, qy-snapped_y)
+    if Point.dot(orthogonalSplineVector, offsetVector) < 0:
+        minOffsetY = -minOffsetY
+    return [snappedSpline, snappedSplineLeadingPoint, snapped_x, snapped_y, subsegmentDistance, splineDistanceS, minOffsetY]
     
 def getXYfromSY(s, y, splineNum, splines, mode = 0):
     ''' Find X,Y coordinate from S,Y data. 

--- a/python/tests/moving.txt	Tue Aug 12 15:33:03 2014 -0400
+++ b/python/tests/moving.txt	Tue Aug 12 17:47:16 2014 -0400
@@ -73,6 +73,8 @@
 >>> alignments = [left, middle, right]
 >>> getSYfromXY(73, 82, alignments)
 [1, 0, 73.81997726720346, 81.10617000672484, 18.172277808821125, 18.172277808821125, 1.2129694042343868]
+>>> getSYfromXY(78, 83, alignments, 0.5)
+[1, 0, 77.03318826883, 84.05388936710071, 13.811799123113715, 13.811799123113715, -1.4301775140225983]
 
 >>> Trajectory().length()
 0