Errata

The parenthetical reads, "typical in a startup when its still building its product". That first "its" should be "it's".

There is a typo error in surname "Vendenberghe". The proper surname sounds: Vandenberghe.

Does the expression ((90210], user_5321} <- {1,1} is correct? What about the correctness of parentheses?

Note from the Author or Editor:
That expression should be rewritten as:

({90210,user_5321}, {1, 1})

Is the word "clean" mandatory in the sentence "The best practice is to start from scratch with clean, raw data"? Isn't "clean data"an antithesis of 'raw data" in the context of the book?

Note from the Author or Editor:
Please replace the word "clean" with the word "unfiltered".

The order of indexes concerning three "f" (user attributes) is inverted (cp. their order three lines above). Is it correct?

Note from the Author or Editor:
Yes the last line on page 204 should read

p_i = \beta_1 f_{i, 1} + \beta_2 f_{i,2}+ \beta_3 f_{i, 3}.

right now we see "f_{1, i}" instead of "f_{i, 1}" for example.

What does it mean: "to shave off nanoseconds 10^-9"? That
nanosecond equals 10^-9 of a second? (It is). 10^-9 of [one] nanosecond?? Something else?

Note from the Author or Editor:
This sentence should read:

Once you get into the optimization process, you find yourself tuning MapReduce jobs to shave off nanoseconds from repetitive processes because you're dealing with petabytes
of data.

There is a typo error in surname "Kolazcyk". The proper surname sounds: Kolaczyk.

In the sentence: "the age vectors of all the
users will be a row in V" is the plural of '"vector" correct?
Why "age vector"? Isn't age a scalar value?

Note from the Author or Editor:
The parenthetical phrase at the bottom of the page should read:

so the vector of ages of all the users will be a row in V

Delete the equal sign and right side of the equation in the first sentence. It should read, "... values theta_j is the answer...". Otherwise the question following makes no sense: the lead in has answered it.

Note from the Author or Editor:
Agreed!

That sentence should start:

In other words, the vector of values θ_j is the answer...

The notation for the number of occurances of the jth word in all emails would not be ambiguous if it were n_j ("n subscript j"), rather than n_c.

Otherwise the ratios of counts used to compute probabilities theta_j and theta_k for two words, j and k, in spam would seem to have the same denominator. Thus, it is better to write,
p(word_j,spam) = theta_j = n_jc/n_j
and
p(word_k,spam) = theta_k = n_kc/n_k

n_c seems more likely to represent the number of spam emails.

Note from the Author or Editor:
This is terrible notation! Please change all the n_{j c} to n_{j s} and please also change all the n_{c} to n_{j c}.

This is for the entire section called "Fancy It Up: Laplace Smoothing"

So it should read "where n_js denotes the number of times that word appears in a spam email and n_jc denotes the number of times that word appears in any email"

Introduction to Machine Learning (Adaptive Computation
and Machine Learning) by Ethem Alpaydim (MIT Press)

It is not Alpayd&#305;m, it's Alpayd&#305;n.

"Thinking back to the previous chapter, in order to use liner regression,..."

should be 'linear'

Page Error Note
p.207 star-up should be "start-up"
p.359 want achieve should be "want to achieve"
p.162-163 section headers are different sizes "Exercise: GetGlue and Timestamped Event Data" and "Exercise: Financial Data" should be same size font
p.68 dgree In figure 3-6, should be "degree"
p.32-33 inconsistent capitalization of random variables: x vs X
p.21-22 indentation is odd and seems arbitrary
index curse of dimensionality missing
p.282 "That experimental infrastructure" strange phrasing

This errata was submitted by Philipp Marek via email.

Errata for Doing data science

I mark /deletions/, and *changes*.
This is in UTF8 -- so eg. a CRLF is shown as down-left pointing arrow: &#8629;


xvii: move 3 words: there is more breath // than depth *in some cases*

xxi: Forgot to mention "Visual Display of Quantitative Information" ... although listed on p37

2: statis/i/tican

14: 1-4 use different shades of gray, or dashes or something like that

30: observed real-world phenomen*a* (or *a* phenomenon)

32: x in seconds? Don't integrate over minutes

38: http://stat.columbia.edu - everything else on github

43: hypo-thesis, not th-esis (?)
2-3 Huma*n* behavi*or* (nouns)
Trying to read associations fails; put Olympics beneath Olympic records?

44: an extension /of/ or variation of

48: an-swered?

49: Did Doug use ... (... "CPC") -- aren't used in text, no need to explain

50: plot(log(), log()): see http://spacecraft.ssl.umd.edu/akins_laws.html, twice.
"6. (Mar's Law) Everything is linear if plotted log-log with a fat magic marker."
bk.homes[which ...] -- indentation of 3rd line wrong
log() <= 5 ... better use <= 1e5 or 100e3 and remove log()

68: 3-6 truth = d*e*gree 2 (top right)

69: x*_2* * x_3

71: x&#8321;�, not x�&#8321;

72: you'd have establish*ed* the bins (or have *to* establish)

73: 3-7 doesn't include the points listed above

74: 3-8 use "x" for new guy, this point is already in 3-7

76: Hamming: shoe +s-s => hose, distance is 2
we start with a Google search ... *which to use*.

77: n.points = length(data)
Why not simply use a boolean vector of some length on data?
swap lines: train <- and #define

78: swap cl <- and #
swap true.labels and #

79: # We're using ... comment not helpful

85: http://abt.cm -- why a different link shortener?
we showed how *to* explore and clean

87: remove line setwd()

90: U of Edinb*o*rough?

101: parallel/-/ly

108: WWW::Mechanize, and generally Perl for text extraction

111,112: script could use a few functions

117: *An Empirical...* format different from other book references or titles

129: "non discrete)" is still a comment, wrong format used
c[, 2] - space before "," missing

131: vlist <- use less space to avoid line break, twice

132: "use holdout group" join to previous line
"vars" within for loop?

137: prop/o/agates

140: 6-3 no colors visible. use distinguisable grays?

141: 6-4 no counts visible

147: what does 6-7 show?

151: 6-8 label both axes with text

155: 6-12 factors not distinguishable

156: this_E is unused

176: "Director of Research..." in one line

177: the modeling part isn't *what* we want

183: AIC Info*r*mation

184: a college studen ... spend *her* time

191: "column which is our response" is still a comment, has wrong format

194: "Google's Hybrid Approach" title => italic

201: simple but comp*l*ete

215: vr = indentation wrong

236: to a*c*cept

241: the Predicted=False row should have FN, TN

246: 2nd mouse/keyboard is not needed, other person should read and think, not type simultaneously

247: discrep*a*ncy

251: partic-ipate ?

254: digital media at&#9251;Columbia (space missing)

281: "Overlapping..." title => italic

287: people that take/s/ some drug -- people take, not the population

293: "Oral..." title => italic

304: (hers is shown ... *)*

341: line 44 is hard to read, code doesn't match other formatting

349: Map*R*educe

351ff: Index:
"Amazon Mechanical Turk" in Amazon
bunch together "causal ..."
bunch together "chaos ..."
"Protocol buffers" instead of "prtobuf"
and probably some more.

Note from the Author or Editor:
32: x in seconds? Don't integrate over minutes

Cathy: change the "measured in seconds" to "measured in minutes" in the above paragraph.

50: plot(log(), log()): see http://spacecraft.ssl.umd.edu/akins_laws.html, twice.
"6. (Mar's Law) Everything is linear if plotted log-log with a fat magic marker."
bk.homes[which ...] -- indentation of 3rd line wrong
log() <= 5 ... better use <= 1e5 or 100e3 and remove log()

Cathy: please indent after the "bk.homes" line as the above lines are indented. Otherwise fine to ignore these suggestions.

73: 3-7 doesn't include the points listed above

Cathy: That's true. We might wanna change it to be more reasonable. I don't have the original data that was plotted here.

74: 3-8 use "x" for new guy, this point is already in 3-7

Cathy: Can erase the "?" point in 3-7 for clarity.

76: Hamming: shoe +s-s => hose, distance is 2

Cathy: this is false. Ignore.

77: n.points = length(data)
Why not simply use a boolean vector of some length on data?

Cathy: ignore

108: WWW::Mechanize, and generally Perl for text extraction

Cathy: ignore.

111,112: script could use a few functions

Cathy: please write your own book with a few functions.

141: 6-4 no counts visible

Cathy: that's ok.

147: what does 6-7 show?

Cathy: X-axis should be labeled "time in seconds"

246: 2nd mouse/keyboard is not needed, other person should read and think, not type simultaneously

Cathy: ludicrous comment. Ignore. Also this is on page 245.