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The latest version of the book is P1.0, released almost 5 years ago. If you've bought a PDF of the book and would like to update it to this version (for free), visit your home page.

By default this page displays the errata for the latest version of the book. If you have a previous version, select it here:

If you've found a new error, please submit it.

  • Typo
  • Tech. error
  • Suggestion
  • Maybe next edition
  • Not a problem
  • Reported in: P1.0 (04-Jul-15)
PDF page: 18
Spent a lot of time getting the sample code to run with Ruby. It seems that the require statement has changed since Ruby 1.9 to not include the local...more...
  • Reported in: P1.0 (24-Dec-15)
Paper page: 22
The rationale for the column value in the random_cell method would be useful to explain. It took me awhile to realize it was for non-rectangular grids...more...
  • Reported in: B7.0 (27-Jun-15)
PDF page: 24
Code examples with line numbers would read more nicely in the kindle version if you label the first line "1" instead of "Line 1". As it is currentl...more...
  • Reported in: P1.0 (24-Nov-18)
Paper page: 26

The code of `to_s` contains `\n` twice. In the current font, that backslash is wuiteclose to a pipe character, `|`.--Jochem

  • Reported in: P1.0 (11-Mar-16)
Paper page: 30

Parameters use the equal sign to assign default values.
So the method declaration should read:
def to_png( cell_size = 10 )--Holger

  • Reported in: P1.0 (16-Aug-15)
PDF page: 43
Quoting from the text: Each iteration of that loop examines all of the linked neighbors of the current cell (line 8), looking for one that is clos...more...
  • Reported in: P1.0 (20-Jul-15)
PDF page: 71

Text "(for example, binary_tree_demo.rb or wilsons.rb)". It should read wilsons_demo.rb.--Carl

  • Reported in: P1.0 (13-Nov-18)
Paper page: 134

Dijkstra's name is misspelled in the header on this page. "Dikstra"

  • Reported in: P1.0 (14-Feb-17)
Paper page: 200
The vertical bias in attributed to the recursive subdivision algorithm is consequence of the implementation rather than the nature of the algorithm it...more...