heineman/python-algorithms

This repository contains the code associated with the "Working With Algorithms In Python" Safari Video. http://shop.oreilly.com/product/110000667.do

python-algorithms's Issues

KDNode and nearest

I'm watching your video on Safari. I read your README regarding the KDNode and nearest. Would you give an example of points where lines 99 to 118 is necessary? I tried the following as a test between your code and the revised version of nearest below. Both gave the same output.

kd = KDTree()
kd.add([2,3])
kd.add([3,4])
kd.add([5,5])
kd.add([9,6])
kd.add([4,7])
kd.add([8,1])
kd.add([7,2])
v = kd.nearest((4,4))
print(v.point)

And simplify the function to

  def nearest(self, min_distance, p):
        """Return closest node from given subtree to point."""

        d = self.distance(p)
        result = None
        if (d < min_distance):
            result = self
            min_distance = d

        pt = None
        if self.isAbove(p) and self.above:
            pt = self.above.nearest(min_distance, p)
        elif self.isBelow(p) and self.below:
            pt = self.below.nearest(min_distance, p)
        if pt:
            return pt

        return result