Week 18

Elements of Machine Learning III: Words, Vectors and Code

Word vectors are a key concept in the application of Machine Learning techniques to textual analysis. A word vector is a multidimensional representation or ‘embedding‘ of a word in a vector space.   The simplest possible embedding is called 1-of-N encoding where each word in a vocabulary of size V is uniquely identified by assigning 1 in a single dimension of a vector of length V with all the other V-1 dimensions of the vector set to 0.  All V words in the vocabulary can be uniquely assigned this way.  It is then possible to use this concept to encode sentences of length C as vectors with corresponding C dimensions combined and normalised to yield a vector of total length 1 with all other dimensions set to 0.  In the last few years, Google’s word2vec has emerged as a de facto standard architecture which builds upon 1-of-N encoding with a neural network language model in which the overall ‘context’ (ie. nearest neighbours) of each word in the text are used as input to train the weights of a hidden layer in the neural net.  Concretely word2vec builds a internal distributed representation where each word is spread across all inputs which effectively serves as a numerical proxy for the word ‘meaning’.  The word2vec architecture is comprised of two models which are mirror images of each other and together constitute an auto-encoder mechanism:

  • Continuous Bag of Words (CBOW): allows the prediction of a single word given its context words.
  • Skip-gram: allows the prediction of context words given a single input word.

To get a better feel for what this actually means, below is some basic example code that demonstrates how a corpus consisting of four sentences can be represented first as a simple bag of words (BOW) using scikit-learn’s CountVectorizer and secondly as a normalized BOW representation using TfidfVectorizer.  The latter stands for “Term Frequency, Inverse Document Frequency” and is a way to score the importance of words (or “terms”) based on how frequently they appear across the corpus.  The TfidfVectorizer is initialised to process both single words and bigrams (adjacent words) which allows it to pick out specific uses of the interrogative ‘is the’  albeit at the cost of a bigger vocabulary:

import numpy as np
from sklearn.feature_extraction.text import CountVectorizer
from sklearn.feature_extraction.text import TfidfVectorizer

corpus = ['The sun is shining',
 'The weather is sweet',
 'Is the sun shining?',
 'The sun is shining and the weather is sweet']

def dumpVocab(vocab):
 arr = []
 for k,v in vocab.items():
 arr.append((v,k))
 arr.sort()
 print(' '.join([(str(v[0]) + ':"' + v[1] + '"') for v in arr]))

print("---- Corpus ----")
print(corpus)
sentences = np.array(corpus)

# 1-gram (individual words)
print("---- 1-gram BOW model ----")
vectorizer = CountVectorizer()
bag = vectorizer.fit_transform(sentences)
print(bag.toarray())
dumpVocab(vectorizer.vocabulary_)
isthe = 'is the'
theis = 'the is'
print("Can we disambiguate '%s' from '%s'? Expect no." % (isthe,theis))
print(vectorizer.transform([isthe]).toarray())
print(vectorizer.transform([theis]).toarray())

# tfidf with ngram_range (1,2) which allows us to 
# extract 2-grams of words in addition to 
# 1-grams (individual words)
print("---- (1,2) ngram tfidf model ----")
vectorizer = TfidfVectorizer(ngram_range=(1,2))
bag = vectorizer.fit_transform(sentences)
print(bag.toarray())
dumpVocab(vectorizer.vocabulary_)
print("Can we disambiguate '%s' from '%s'? Expect yes." % (isthe,theis))
print(vectorizer.transform([isthe]).toarray())
print(vectorizer.transform([theis]).toarray())

Running the above code yields this output:

---- Corpus ----
['The sun is shining', 'The weather is sweet', 'Is the sun shining?', 'The sun is shining and the weather is sweet']
---- 1-gram BOW model ----
[[0 1 1 1 0 1 0]
 [0 1 0 0 1 1 1]
 [0 1 1 1 0 1 0]
 [1 2 1 1 1 2 1]]
0:"and" 1:"is" 2:"shining" 3:"sun" 4:"sweet" 5:"the" 6:"weather"
Can we disambiguate 'is the' from 'the is'? Expect no.
[[0 1 0 0 0 1 0]]
[[0 1 0 0 0 1 0]]
---- (1,2) ngram tfidf model ----
[[ 0. 0. 0.30078176 0.45442879 0. 0.
 0.36789927 0. 0.36789927 0.45442879 0. 0.
 0.30078176 0.36789927 0. 0. 0. ]
 [ 0. 0. 0.27304707 0. 0.41252651 0. 0.
 0. 0. 0. 0. 0.41252651 0.27304707
 0. 0.41252651 0.41252651 0.41252651]
 [ 0. 0. 0.26887374 0. 0. 0.51524026
 0.32887118 0. 0.32887118 0. 0.51524026 0.
 0.26887374 0.32887118 0. 0. 0. ]
 [ 0.30496979 0.30496979 0.31829178 0.24044169 0.24044169 0.
 0.19465827 0.30496979 0.19465827 0.24044169 0. 0.24044169
 0.31829178 0.19465827 0.24044169 0.24044169 0.24044169]]
0:"and" 1:"and the" 2:"is" 3:"is shining" 4:"is sweet" 5:"is the" 6:"shining" 7:"shining and" 8:"sun" 9:"sun is" 10:"sun shining" 11:"sweet" 12:"the" 13:"the
 sun" 14:"the weather" 15:"weather" 16:"weather is"
Can we disambiguate 'is the' from 'the is'? Expect yes.
[[ 0. 0. 0.41988018 0. 0. 0.8046125
 0. 0. 0. 0. 0. 0.
 0.41988018 0. 0. 0. 0. ]]
[[ 0. 0. 0.70710678 0. 0. 0. 0.
 0. 0. 0. 0. 0. 0.70710678
 0. 0. 0. 0. ]]

It’s important to realise that CBOW and Skip-gram are unsupervised methods which do not require labelled data to work as illustrated above. Having said that, CBOW can be combined with a classifier for example in the case of sentiment analysis where separate individual sentences in the corpus are ascribed a rating of 1 for positive sentiment and 0 for negative sentiment.   Training in that scenario results in certain word contexts being more strongly associated with positive or negative.  Spam filtering works in a similar way.  This combination of unsupervised and supervised learning to derive sentiment is an exercise I hope to return to in a later post.

The inverse process of supplying likely context from word input using a skip-gram model can be employed (albeit after ingesting a lot of training material) to ‘generate’ realistic output like the AI poetry that Wired refer to here:

i went to the store to buy some groceries.
i store to buy some groceries.
i were to buy any groceries.
horses are to buy any groceries.
horses are to buy any animal.
horses the favorite any animal.
horses the favorite favorite animal.
horses are my favorite animal.

For now, it’s worth taking a step back and reflecting on the bigger picture implications of this exercise.  Namely that it is possible using Machine Learning concepts like word2vec to derive insight and predictive capability from a corpus purely by training a model on its raw text content alone.  You coach not code.  This is the profound insight at the core of Wired’s dramatically titled “End of Code” June edition:

In traditional programming, an engineer writes explicit, step-by-step instructions for the computer to follow. With machine learning, programmers don’t encode computers with instructions. They train them. If you want to teach a neural network to recognize a cat, for instance, you don’t tell it to look for whiskers, ears, fur, and eyes. You simply show it thousands and thousands of photos of cats, and eventually it works things out. If it keeps misclassifying foxes as cats, you don’t rewrite the code. You just keep coaching it.

The first public outing of Viv’s much-anticipated AI this week takes things a stage further still.  Viv’s creators are Dag Kittlaus and Adam Cheyer who “created the artificial intelligence behind Siri“.  They claim Viv is a conceptual leap ahead of Siri in its ability to generate unique code on the fly to handle specific requests:

Onstage it showed off what it claims is a breakthrough: “dynamic program generation.” With every verbal request Viv dynamically spit out code showing off how it understood and handled the request. That would hypothetically allow developers to build out a robust conversational UI for their services simply by speaking to Viv and tweaking the code she generates in return.

The combinatorial advances with the data structures and algorithms and compute power that can be applied to them are happening at an accelerating pace which will profoundly change society in the coming years.  It’s hard to be sure that anyone is fully in control or sure of where we’ll end up. Disquiet around that realisation likely underlies Salon’s concern that we need to “fear our robot overlords” and “take artificial intelligence seriously”:

While it’s conceptually possible that an AGI really does have malevolent goals — for example, someone could intentionally design an AGI to be malicious — the more likely scenario is one in which the AGI kills us because doing so happens to be useful. By analogy, when a developer wants to build a house, does he or she consider the plants, insects, and other critters that happen to live on the plot of land? No. Their death is merely incidental to a goal that has nothing to do with them.

Fear our new robot overlords: This is why you need to take artificial intelligence seriously

Chatbots and HAAI

How will they explain how they came up with product recommendations, including whether they’re based on data collected about consumer habits or are the result of arrangements with companies? Without an explanation, consumers might not trust the recommendations and therefore be less willing to use the services.

  • The question seems all the more relevant in light of evidence that many of us seem to be comfortable conversing with bots, sometimes more so than with humans.  We may end up sharing our most intimate thoughts with them to be stored and mined for eternity.  There is a certain horrible inevitability about the direction of travel given the underlying commercial imperative is a ‘race to data’:

“Artificial Intelligence algorithms are continuing to improve, however although the algorithms may be open source, the benefits seem to accrue to those with the most data on which to train those algorithms. So the core competency needs not only to be applying the right algorithms to the right problems, but being the primary source for a unique data set.” — Matt Hartman, Director of Seed Investments at Betaworks

“Business Insider and Socialbakers just published data at the Engage conference in Prague on communications between customers and companies in Messenger which shows that there are five times as many private messages occurring as there are public wall posts being made on Facebook. Yet company employees on average take 10 hours to respond to a direct message. That suggests there is a huge opportunity for bots to deal quickly with simple questions from customers, freeing up the humans to address the more complicated problems.”

  • Another day, another AI messaging proposition backed by millions in VC funding.  They can’t possibly all make it can they? This one is called Lola, it’s iOS only and focussed on a single vertical, namely travel bookings, the same space GoButler are targetting.  This VentureBeat article covering Lola is interesting mainly for providing some genuine insight into the organisational structure required to support an AI messaging startup:

“What we’re doing now with Lola is we’re not bringing back the old school travel agent, ” he explained “We’re trying to reinvent the travel agency. I have engineers, twenty people on the product team, fifteen travel agents, and ten overhead people like me and the designers. I have five people on the AI team.”

3_WeAreOnIt

Machine Learning and Artificial Intelligence

  • Client-side Deep Learning is becoming a realistic prospect thanks to the latest hardware advances from the likes of Nvidia and Movidius:

Both Nvidia and Movidius see that deep learning is the “next big thing” in computation, which is why Nvidia is optimizing its GPUs for it with each new generation, and why Movidius created a specialized platform dedicated to deep learning and other vision-oriented tasks.

  • AI will “definitely kill jobs but that’s ok” because they’re mostly the boring ones according to import.io Chief Scientist Louis Monier. Maybe they are to him but some of the affected individuals will have a great deal of attachment to their work nonetheless:

In Monier’s AI world, then, the future involves “delegat[ing] to robots/AI the boring jobs, and we keep the good ones for ourselves.” This, he insists, is “just like we have always done, from farm animals pulling the plow to steam power and so on.”

  • This video covers similar territory albeit showing how advanced robots are already making irrevocable inroads into Japanese culture and society where in many instances work is already being partitioned between robot and human.  It makes for uncomfortable viewing that especially when considered in the light of Monier’s dismissal. Arguably robots are being pushed hardest in the societies where individualism is least valued in some ways:

Google and Apple

Be careful what you say in your work email account, or in your company Slack channel, or anywhere a record is kept. You never know when and where it’ll come back to haunt you.

Digital Transformation (DX)

  • This related McKinsey DX post is also worth checking out.  It goes into the specifics of a digital transformation rather than cover the generic high-level non-specific fare you typically encounter on this topic. Interestingly, organisational structure is again at the heart of the machine.  McKinsey suggest you need behaviour change instituted top down and a ‘performance infrastructure’ to back it.

  • The last word on DX must go to the inimitable Simon Wardley. This talk entitled “Situation Normal, Everything Must Change” from OSCON 2015 is excellent:

Security

The FBI wants us to believe that strong encryption in consumer products will enable terrorists, but they already have access to encryption. It’s the rest of us that don’t.

  • China’s top hackers compete for Geek-Pwn:

may-12-rtr2w766-e1463041017213

They discovered they could pull off disturbing tricks over the internet, from triggering a smoke detector at will to planting a “backdoor” PIN code in a digital lock that offers silent access to your home

Blockchain and Bitcoin

  • Blockchain and Wall Street:

“All day we mine 50 bitcoins.  24 hours this machine never sleeps.”

The Internet of Things, 3D-Printing and Hardware

The reduced cost of personal manufacturing tools is enabling makers to develop hardware faster than established companies and deliver that hardware directly into the hands of customers even faster.

Bring that "Sweet Tube Sound" to the Raspberry Pi!

fhg2dagf8nnqdrtfysff

“For example, you can click the button to unlock or start a car, open your garage door, call a cab, call your spouse or a customer service representative, track the use of common household chores, medications or products, or remotely control your home appliances.”

AWS_IoT_button_short

Science

  • Regular readers of the blog will know the Fermi Paradox is often namechecked.  This Quartz post provides more reasons to worry by highlighting that while the number of exoplanets we have found as a species is increasing exponentially, we face the enormous reality that:

in decades of searching for aliens, we’ve never found any signs. No radio signals. No odd objects arounds stars. No fly-bys of spaceships. Nada. This apparent contradiction is the Fermi Paradox: “Where is everyone?”

atlas_rJblS1Wz@2x

Software

def logFunction(*args,**kwargs):
 log = args[0] # True or False
 def fwrapper(fn):
   def foriginal(*args,**kwargs):
     if log:
       print("ENTER: %s(%s)" % (fn.__name__,args))
     resp = fn(*args,**kwargs)
     if log:
        print("EXIT: %s" % (fn.__name__))
     return resp
   return foriginal
 return fwrapper

@logFunction(True)
def doSomething(s):
  print("Something: %s" % s)

doSomething('something')

The truth is, it simply isn’t easy to slide into a development gig, even if it’s an apprenticeship. You need connections, people to vouch for you, a GitHub account maintained over time and more. Despite advances in equal opportunity, if you’re an underrepresented minority, you’re going to have to be twice as good as everyone else. And that’s simply to demonstrate competence.

  • Besides, it means you won’t have to face the potential consequences of your mistakes. If you ever had a poor smartphone software update experience, it pales in comparison to the one inflicted on this Japanese satellite:

The cause is still under investigation but early analysis points to bad data in a software package pushed shortly after an instrument probe was extended from the rear of the satellite. JAXA, the Japanese space agency, lost $286 million, three years of planned observations, and a possible additional 10 years of science research.

the Prince symbol is not eligible for inclusion in Unicode, which “does not encode personal characters, nor does it encode logos.” Still, though, the Unicode geeks on mailing lists have talked about it, charmingly using the shorthand TAFKAP (for The Artist Formerly Known As Prince).

Prince_logo.svg_

Leadership and Work

I hope that you live your life — each precious day of it — with joy and meaning. I hope that you walk without pain — and that you are grateful for each step.

 Estimated impacts of working hours on cognitive skills

At a time when the world’s biggest election campaign is being driven by fear, isolation and intolerance, it is great to see Londoners ignore those ugly forces. Congratulations to Sadiq Khan for becoming the first directly elected Muslim mayor of a major western city.

Trump

Hitler’s enablers in 1933—yes, we should go there, instantly and often, not to blacken our political opponents but as a reminder that evil happens insidiously, and most often with people on the same side telling each other, Well, he’s not so bad, not as bad as they are. We can control him. (Or, on the opposite side, I’d rather have a radical who will make the establishment miserable than a moderate who will make people think it can all be worked out.) Trump is not Hitler. (Though replace “Muslim” with “Jew” in many of Trump’s diktats and you will feel a little less complacent.) But the worst sometimes happens. If people of good will fail to act, and soon, it can happen here.

  • Peter Thiel, co-founder of PayPal “a company co-founded by an immigrant (Max Levchin), backed by an immigrant (Mike Moritz) and sold to a company founded by an immigrant (Pierre Omidyar)” may be a notorious Silicon Valley libertarian but he “can’t intellectualize his way out of supporting Donald Trump:

Donald Trump wants to ban Muslims, and most other immigrants, from entering the United States and talks about women as if they’re his personal sex toys. He wants to cut America off from the world and sees no reason to rule out dropping a nuclear bomb on Europe. Oh, and his own ex-wife has accused him of rape. … These are not the policies of a libertarian, or even of a creationist (which Thiel also claims to be). These are the policies of a fucking asshole. … I can’t speak for anyone else here at Pando, but I’m utterly ashamed that we have him as an investor.

What he’s hinting at is that he would use the anti-trust division of the Justice Department to go after a newspaper publisher who writes stories that he doesn’t like. … In an ordinary democracy, comments like these would practically be disqualifying for a presidential candidate. In America 2016, they barely garner notice. If anything, Trump is using it as a campaign selling point. Perhaps he should create a new tab on his campaign website titled “Planned Abuses of Power.”

Society

  • This article about the world of gold cars and binary trading is an eye-opener:

ak47lamps Three gold cars from Saudi Arabia (back-front) a 6x6 Mercedes G 63, Rolls-Royce Phantom Coupe and Lamborghini Aventador have received parking tickets on Cadogan Place in Knightsbridge, London. PRESS ASSOCIATION Photo. Picture date: Wednesday March 30, 2016. See PA story TRANSPORT Knightsbridge. Photo credit should read: Stefan Rousseau/PA Wire

The Mayo Clinic says that if you are planning to use a device in bed that you hold it 14 inches away from your face and dim the brightness which further reduces the blue wavelength light from reaching your retina. The National Sleep Foundation goes one giant step further and recommends that you not use any device within an hour of attempting to fall asleep. Given their research showing that 90% of American adults use their electronic devices within an hour of bedtime at least a few nights a week, this may be difficult.

Age is an even more fraught subject when tangled up with gender. The older gentleman is distinguished. The older woman is . . . haggard. Why do we talk about Hillary Clinton’s age but not Donald Trump’s, although he is a year older?