The errata list is a list of errors and their corrections that were found after the product was released.
The following errata were submitted by our customers and have not yet been approved or disproved by the author or editor. They solely represent the opinion of the customer.
Color Key: Serious technical mistake Minor technical mistake Language or formatting error Typo Question Note Update
| Version |
Location |
Description |
Submitted by |
Date submitted |
| Printed |
Page 17
15th line from the top |
"42 = RaDio" should be "41 = RaDio"
|
John Tyo |
Jul 20, 2009 |
| Printed |
Page 91
See also - 1st bullet point |
http://www.ideagenerationmethods.com/methods/card-decks.html is a dead link - leads to a domain placeholder
page.
|
Anonymous |
|
| Printed |
Page 167
3rd paragraph |
When finding the century-item for any Gregorian date, the algorithm given starts with integer-dividing the
first two digits of the year by 4, followed by getting the "mod 7" of this intermediate result.
However, this does not correspond to the numbers given in the example, and does not give the results that
are found in table 4-11.
The algorithm should instead start with getting the "modulo 4" (rather than integer division) of the first
two digits of the year, and the example should be altered to correspond to this.
|
Anonymous |
|
| Printed |
Page 167
3rd paragraph |
The method for calculating the century-item adjustment for Gregorian dates is
incorrect, since 5 mod 7 = 5, not 0. If we had used the proposed method and
calculated 5 mod 7 correctly, then we would actually get:
20 / 4 = 5
5 mod 7 = 5
3 - 5 = -2
2 * -2 = -4?
Obviously this does not yield the result in Table 4-11, p. 166. If we omit the
modulo operation and replace the division with a modulo 4 operation, then we do get
the results in Table 4-11:
1700s:
17 mod 4 = 1
3 - 1 = 2
2 * 2 = 4
1800s:
18 mod 4 = 2
3 - 2 = 1
2 * 1 = 2
1900s:
19 mod 4 = 3
3 - 3 = 0
2 * 0 = 0
2000s:
20 mod 4 = 0
3 - 0 = 3
2 * 3 = 6
2100s:
21 mod 4 = 1
3 - 1 = 2
2 * 2 = 4
2200s:
22 mod 4 = 2
3 - 2 = 1
2 * 1 = 2
2300s:
23 mod 4 = 3
3 - 3 = 0
2 * 0 = 0
In general, perhaps the author meant, "To get the century-item for any Gregorian
date, cast out fours, subtract the result from 3, and multiply the difference by 2."
Or, in rough mathematical terms:
2 * (3 - (C mod 4))
where C is the century, such that C = 20 for the year 2005.
Note from the Author or Editor:
(This was submitted originally by a user to "Mind Hacks") |
Anonymous |
Feb 05, 2009 |