Errata for the 2nd Edition, prior to 10th printing (January 2013) and reflected in online version

19, l+5 T should be Tau
56, f(x) should be a vector
91, equation (3.81) changed
97, Ex 3.7, added some detail on prior
105, bullet - this is true whether or not the fitted values sum to 1 (Laurell Stell)
109, eq 4.11 changed to have the more traditional formula
133, the Wolfe dual (4.52) should also include equality constraint of Eq. (4.51).
135-136 ex 4.2 changed. There were mistakes before, and misleading def for Sigma_B
159, Fig 5.9 - the figure was incorrect- variances were plotted rather than SE
224, line 11 - the transpose needs to be an inverse for h(x_0)
236, (7.45) 2 missing in denom of third expression on right
"Huffmann coding" should have only one "n".
357, eq 10.32 should have a 1/2 on right hand side
358, below (10.34), extra ) and should be ^T
359, 6 lines into Section 10.2.2 - need a close brace and a transpose
386, Exercise 10.8(b): The denominator in the last line should be exponentiated.
439, Bullet point 4 from the top is erroneous. The truth is on page 111: LDA or QDA was among
the top three classifiers for 10 of the 22 datasets in the STATLOG project. LDA was among the
top three classifiers for 7 of the 22 datasets.

457, Expression (12.66) should read max \theta^T Y^T S Y\theta.
520, figure labels changed
541, Item 1 should needs a transpose on the right X_\ell
559, (14.78) change s_ to a_, make subscripts of S all ell
647, The first line of Exercise 17.5 should refer to Section 17.3.1, not Section 17.4.1.
648, The reference (17.28) should not be repeated in Exercise 17.11.
653, line 10 delete "absolute"
661, the methods of Section 18.3 ....
694, eq. (18.55): Left absolute value bracket for last term has to be lifted to the numerator.
698, line 6: Proofs of result (18.53), not (18.20)
717, last line - should be "Relaxed Lasso"


Thanks to

David Epstein
Andre Ferrari
Thomas Lengauer
Steven Lyuee
Edward Malthouse
Kajsa Mollersen
Scott Powers
Ludi Rehak
Laurell Stell
Jonathan Taylor
Can Yang
Peng Yu
Qin Zeng

Errata for the 2nd Edition, prior to 5th printing (December 2010) and reflected in online version

5, hyphenation changed
23, Curse picture - change d to p
61, lcweight -> lweight
71, changed first entry in table 3.4
72, missing parenthesis
74, f_k needs a hat
89, Dantzig selector change s to t
98, put 1/2 in exercise 3.27
126, l-6 "indentify"
127, Friedman reference changed
165, changed thin-plate spline def to simpler equivalent form
275, extra . in EM formula
279, word missing
297, "," after V
321, extra ","
339, punctuation
348, extra space removed
353, space included
360, missing "to"
426, missing period
428, \alpha_0 should be \beta_0
441, funny braces changed in line 5
489, greater "than"
541, A should be bold
544, grammar change
578, matrix L
579, Bibliography typset wrong near end
581, R_\ell the R should be bold
588, space added and Case change
601, "depends" line 7
612, Figure 16.2 added a parenthesis about relative to error of constant model
618, capital M
642, line 15 "maximization"
649, extra brace
657, 2 lines below 18.11 subscript wrong
661, put 1/2 in 18.18
661, reference changed
668-669, reference Leslie changed
679, (2) and (3) to (2a) and (2b)
684-685, "Treatment" vs "Sensitivity"; formula for se changed
688, punctuation in figure changed
708-709, reference fixed
716, reference Leslie et al corrected

These errors were found from January 2010 to December 2010 by

Moritz Gschwandtner
Iain Johnstone
Mehrdad Jafarr Mamaghani
Nelson Ray
Kinh Tieu
Enrique Tobis
Can Yang
Tian Zheng

A big thank you to Thomas Lengauer and Stephen Milborrow for their extensive errata reports.

Errata for the 2nd Edition, second printing (July, 2009),

page 68, equation (3.52): put a 1/2 in front of RSS
page 103, line -3: put a ^T on x
page 104, equation (4.5): as in line 103. Since y_i is a column vector (length K), care is needed in constructing the fitted values
page 215, last line: colors were incorrect
page 216, figure 6.17: the fitted mixture was plotted incorrectly, using the variances as standard deviations!
page 257, line 2 of "Bibliographic Notes": Allen reference changed from 1977 to 1974.
page 283. line -8: eleven trees are shown.
page 349, equation (10.23): error fixed in second line
page 504, 2 lines below (14.22): changed "variables" to "observations". In fact, the observation vectors are standardized as if they were variables.
page 570-571, lines -1 and +1: First edition had a square-root of S_M, which is removed here. Text still referred to this, so was altered.
page 584, line +1: since "it" is easy.
page 587, line+1: parens around (section 8.7).
page 588, line 2(a) in Algorithm 16.1: upside-down hat on \alpha.
page 649, line -1: Var(epsilon) is 1; needed sigma^2 instead.
page 658, fourth paragraph: Line 3 of Table 18.1, not Line 2.
page 661, equation (18.19): beta has two indices
page 716, Leslie reference: "protein", not "pretein"
page 686, line above (18.42): would like "to" test...
page 700: see page 257.


These errors were found from July 2009 to December 2009 by

Theodore Alexandrov
Jacob Bien
Francesco Dinuzzo
David Goldberg
Diego Kuonen
Yan Li
Phielipp Mariano
Stephen Milborrow
Changyi Park
Patrick Perry
Jason Rennie
Daniela Witten

Errata for the 2nd Edition, first printing (Feb, 2009),

page 2, line+17 "... focus of Chapter 14"
page 26, 27 " colors are orange and blue in figure 2.9
page 245, line -5 "left" -> "top"
page 509, section 14.3.6. There are errors in this subsection relating k-means clustering to the total distance measure 14.28. See the explanation here.
page 571, line +1 "that" -. "than"
page 687, line-2. Reference to figure should be "Figure 18.19 shows..."

These errors were found from February 2009 to July 2009 by
Dave DeBarr
Thomas Lengauer
Ilana Belitskaya-Levy
Kinh Tieu
Daniella Witten