Errata

The Bloom Filter Summary on page 115 uses the wrong Boolean operator in the search() function. The psuedocode shows the following line:

if checkbit | bits = 0 then

This line should instead read:

if checkbit & bits = 0 then

The corresponding Python code shown on page 117 has the correct Boolean operator.

Note from the Author or Editor:
The summary code has the typo, and the actual Python code is correct.

The function "contains" in example 5-12 returns true no matter what.

"True" should be within the while loop as a condition of node == node.value (instead of outside). It should also be uppercase.

The function should explicity return False if it exits the while loop.

Minor typo "ielif" instead of elif in the same section.

Note from the Author or Editor:
The code in the repository is correct, and wasn't printed properly in the book. It should be:

def __contains__(self, target):
"""Check whether BST contains target value."""
node = self.root
while node:
if target < node.value:
node = node.left
elif target > node.value:
node = node.right
else:
return True
return False

At location 1899 in the MOBI version of the book, in the Grahamscan implementation, the code computes polar angles using the formula Math.atan2( pts[ n-2]. getY() - lowest, pts[ n-2]. getX() - pts[ n-1]. getX());. However, the variable lowest indexes the pts array. The variable used here should be lowestY or the code should instead use pts[lowest].getY().

Note from the Author or Editor:
Yes, change code so it reads:

double firstAngle = Math.atan2(pts[0].getY() - lowestY, pts[0].getX() - pts[n-1].getX());
double lastAngle = Math.atan2(pts[n-2].getY() - lowestY, pts[n-2].getX() - pts[n-1].getX());