Neil Lawrence's opening course

Neil Lawrence is Professor at the University of Sheffield. He has worked on unsupervised learning for a long time, and has developed algorithms applicable to dimensionality reduction such as the Gaussian Process Latent Variable model (GP-LVM), see the JMLR paper here.

He has a superb inaugural lecture in which he talks about Machine Learning. The link to the starting page to see that video is here. It opens some embedded and annoying player but it is worth dealing with it.

Neil Lawrence's Inaugural Lecture

Title: Life, The Universe and Machine Learning

Time: 17:15 Thursday 6th September 2012

Venue: St George's Church Lecture Theatre, University of Sheffield

Abstract
What is Machine Learning? Why is it useful for us? Machine learning algorithms are the engines that are driving forward an intelligent internet. They are allowing us to uncover the causes of cancer and helping us understand the way the universe is put together. They are suggesting who your friends are on facebook, enabling driverless cars and causing flagging potentially fraudulent transactions on your credit card. To put it simply, machine learning is about understanding data.
In this lecture I will try and give a sense of the challenges we face in machine learning, with a particular focus on those that have inspired my research. We will look at applications of data modelling from the early 19th century to the present, and see how they relate to modern machine learning. There will be a particular focus on dealing with uncertainty: something humans are good at, but an area where computers have typically struggled. We will emphasize the role of uncertainty in data modelling and hope to persuade the audience that correct handling of uncertainty may be one of the keys to intelligent systems.

I have no mouth but I must scream

Some years ago I was having insomnia and I decided to surf the Internet. I don't know whether I was looking for some Matrix/Level 13-related topic, or some weird science fiction. But I came across a nice short tale, called "I have no mouth but I must scream", which kept me amazed through the night. I remember that I looked for information about it since it left me chilled.

I post here a couple of nice videos that popped up in a later search in autumn.

Kaggle

Reading mathbabe's blog, I learnt about Kaggle. This is a site that provides data so that data analysts can put their techniques to work. This data is provided by institutions who are interested in having their data analyzed. Then, the data is analyzed in the form of a contest, and he who gets the best results by the time the competition ends, wins a prized paid by the data owner. This is best summarized by its Wikipedia's page:

1. The competition host prepares the data and a description of the problem. Kaggle offers a consulting service which can help the host do this, as well as frame the competition, anonymize the data, and integrate the winning model into their operations.
2. Participants experiment with different techniques and compete against each other to produce the best models. For most competitions, submissions are scored immediately (based on their predictive accuracy relative to a hidden solution file) and summarized on a live leaderboard.
3. After the deadline passes, the competition host pays the prize money in exchange for "a worldwide, perpetual, irrevocable and royalty free license [...] to use the winning Entry", i.e. the algorithm, software and related intellectual property developed, which is "non-exclusive unless otherwise specifies

I have seen interesting designs and topics. It is, no doubt, a very interesting source and might even provide a good topic for a thesis, from the practical point of view. I have yet to study it more deeply.

Hitler suffers from C++!

Paper submitted!

At last!!!

It is very hard to make up a novel theory and write the most you can about it, the best you can, and build a manuscript that conforms to the journal's standards.

I have survived!

43 pages in total. I am happy with the result, though I reckon I could have told things differently. In any case, this allows me to move on. I am back writing on the blogs!

The paper contains a machine learning technique that exploits statistical properties of the data. I might later submit the paper to the arXiv. Today, I am officially on vacation, after having invested all summer working on the paper.

In the course of my research I have come across interesting things. I will comment on them starting tomorrow.

Using Whatsapp on your PC

I have never been a huge fan of cell phones. I am one of those people who think that a phone is just a phone, you use it to speak to others and keep in touch, but not to carry Youtube with you all around.

However, my buddies have started to go into silent mode from me and the reason is that they only use Whatsapp now, so no matter where they are they agree to meet or to do anything on short notice. This leaves me in a very miserable position.

What I did is the following:

1. I instaled the Android SDK that comes with an emulator.
2. In the AVG Manager, in the image I created to emulate a Smartphone, I added the property hw.keyboard with the value yes so I could use my PC keyboard to write into the virtual phone. You can also edit your confil.ini that is located under your user directory ~\.android\avd\device.avd\, and add hw.keyboard=yes .
3. I downloaded Whatsapp from the virtual device.
4. I installed the app (believe it or not it was the most difficult part for me, finding out how to reach the downloaded files, I downloaded it three times).
5. During the first execution, it asked me for my real phone number and they sent a regular SMS to my (physical) phone.
6. I then added my friends' phones to my contact in Android and it automatically marked them as using Whatsapp.
7. Then one of them added me to the groups they were using to meet.

Declaration of linear independence

I've been very busy (pinyin for beginners: Wo hen mang, simplified: 我很忙) so let's have some nerdy fun. Via mathbabe's blog, the declaration of linear independence:

IN EUCLIDEAN SPACE, JANUARY 28, 1988

When, in the course of a proof, it becomes necessary for a set to dissolve the argument which has connected it with a theorem, and to assume among the powers of mathematics a position above that of the mathematician, a decent respect for the axioms requires that a rigorous justification be given.
We hold these truths to be self-evident: that all nonzero vectors are created equal; that they are endowed by their definer with certain unalienable rights; that among these are the laws of logic and the pursuit of valid proofs; that to secure these rights, logical arguments are created, deriving their just powers from axioms; that whenever any argument becomes destructive of these ends, it is the right of the vectors to alter or to abolish it, and to institute a new argument, laying its foundation on such principles, and organizing its powers in such form, as to them shall seem most likely to reach the correct conclusion. Prudence, indeed, will dictate that theorems long established should not be changed for light and transient causes, and accordingly all experience hath shown that sets are more disposed to accept the conclusions of arguments than to right themselves by abolishing the arguments. But when a long train of abuses and usurpations, pursuing invariably the same object, evinces a design to reduce them to zero in a non-trivial way, it is their right, it is their duty to throw off such argument, and to provide new proofs for their future security. Such has been the patient sufferance of these vectors, and such is now the necessity which constrains them to alter these arguments. The history of Professor Eigen is a history of repeated injuries and usurpations, all having in direct object the establishment of dependence among these vectors. To prove this, let facts be submitted to a candid world.
He has refused to acknowledge that he obtained a zero matrix only by multiplying our coordinate matrix by a zero matrix.
He has restricted our freedom of movement by requiring us all to live in the same hyperplane, even though we cannot all fit in one.
He has attempted unsuccessfully to invert our coordinate matrix, and, having overlooked the inverse, has concluded that the coordinate matrix is singular.
He has changed bases repeatedly for opposing with manly firmness his attempts to place us in the span of fewer vectors than the dimension of the space.
He has erected a multitude of new formulas and sent hither swarms of new functions to force our directions into a proper subspace of the vector space.
He has kept among us vectors to be orthogonal to all of us without the consent of those of us whose dot product with them is nonzero.
He has abdicated the axioms here by committing mathematical errors in computing a zero determinant for our coordinate matrix.
In every stage of these oppressions we have petitioned for redress in the most humble terms; our repeated petitions have been answered only by repeated injuries.
A mathematician whose arguments are thus marked by every error is unfit to prove the theorem which he attempts to prove.
Nor have we been wanting in attentions to Professor Eigen. We have warned him from time to time of flaws in his arguments. We have reminded him of the circumstances of our definition, we have appealed to his knowledge of the axioms, and we have requested him to disavow these usurpations which would inevitably destroy the validity of his arguments. He has been deaf to the voice of logic. We must therefore acquiesce in the necessity which denounces our separation and hold him as we hold the rest of mathematicians, an enemy when he is wrong, a friend when he is right.
We, therefore, the members of set S in vector space V, appealing to the supreme judge of mathematics for the rectitude of our intentions, do solemnly publish and declare that these vectors are, and of every right ought to be, a free and independent basis; that they are absolved from all subjection to Professor Eigen's theorems, and that all restriction of them to a hyperplane is, and of right ought to be, totally dissolved; and that as a basis, they have full power to span the space, form invertible coordinate matrices, give unique linear combinations equal to a given vector, and to do all other acts and things which a basis may of right do.
And for the support of this declaration, with a firm reliance on the protection of the properties of a vector space, we mutually pledge to each other our magnitudes, our directions, and our sacred honor.
In witness whereof we have signed our coordinates with respect to an appropriate orthonormal basis, and found them to constitute a triangular matrix with nonzero diagonal elements.