New landing page

If you visit you will now see a new design which conforms to the standard “book product webpage” format. I am very pleased with the result, which was an attempt to mimic other good book product pages.

The design process took me about three weeks. Most of the time was spent on the copy editing. The ability to “put stuff on the page” you have with html + css is much more powerful that LaTeX. And with webfonts becoming the norm now, one cam make very beautiful sites very quickly.

Check it out:

The web we still have

The facebookification of the Internet brings with it a stupidification of the content that people produce and share.
The old web was about blog posts (long, though-out pieces of writing) which automatically form links to each other (through trackback) so that a conversation can emerge without the need for a centralized service.

Trackbacks are awesome! For example, I can make this post appear on quora if I embed some javascript (their embed code) which will ping the quora server:
Read Quote of Ivan Savov’s answer to Machine Learning: Does Topic Modeling need a training stage when using Gibbs sampling? And why does it work? on Quora

We need to cherish this kind of distributed technology, because it is the way out of the walled gardens. They are the living proof that you can have social without central.

LDA, BTW, is short for Latent Dirichlet Allocation which is a powerful way to classify documents according to the topics they contain.

Strang lectures on linear algebra

Professor Gilbert Strang’s video lectures on Linear Algebra have been recommended to me several times. I am very impressed with the first lecture. He presents all the important problems and concepts of LA in the first lecture and in a completely as-a-matter-of-fact way.

The lecture presents the problem of solving n equations in n unknowns in three different ways: the row picture, the column picture and the matrix picture.

In the row picture, each equation represents a line in the xy plane. When “solving” these equations simultaneously, we are looking for the point (x,y) which lies on both lines. In the case of the two lines he has on the board (2x-y=0 and -x+2y=3) the solution is the point x=1, y=2.

The second way to look the system of equations is to think of the column of x coefficients as a vector and to think of the column of y coefficients as another vector. In the column picture, solving the system of equations requires us to find the linear combination of the columns (i.e., $x$ times the first column plus $y$ times the second column) gives us the vector on the right hand side.

If students start off with this picture, they will be much less mystified (as I was) by the time they start to learn about the column space of matrices.

As a side benefit of this initial brush with linear algebra in the “column picture”, Prof. Strang is also able to present an intuitive picture for the formula for the product between a matrix and a vector. He says “Ax is the combination of the columns of A.”  This way of explaining the matrix product is much more intuitive than the standard dot-product-of-row-times-column approach. Who has seen them dot products? What? Why? WTF?

I will definitely include the “column picture” in the introductory chapter on linear algebra in the book. In fact, I have been wondering for some time how I can explain what the matrix product Ax. I want to talk about A as the linear transformation TA so that I can talk about the parallels between $x$, $f:R \to R$, $f^{-1}$ and $\vec{v}$, $A$, $A^{-1}$. Now I know how to fix the intro section!

Clearly you are the master of the subject. It is funny that what started as a procrastination activity (watching a youtube video to which I just wanted to link to) led to an elegant solution to an old-standing problem which was blocking my writing. Sometimes watching can be productive 😉  Thank you Prof. Strang!

Target revenue

I did a little calculation regarding what kind of sales figures I would need to make it to the 100k income range (which is my current standard for “success” in a technical field). If I can make deals with 100 Universities, and ship ship 100 copies of the book to each of them, then I am done:

I think it is totally doable with the MATH and PHYSICS title alone within the next couple of years. So fuck the job world. I am doing my own thing!

Showing off with python

2:57AM on a Monday. I have to be up at 8AM. The faster I get the job done the more sleep I get. Sounds like the kind of thing to motivate a person.

TASK: Parse an access.log file and produce page visit trace for each visitor. Ex: on Monday at 3pm   (Montreal, Firefox 4, on Mac OS X):
  /contents          (stayed for 3 secs)
  /derivatives       (stayed for 2m20sec)
  /contents          (6 secs)
  /derivative_rules  (1min)
  /derivative_formulas  (2min)

I had already found some access.log parsing code,  and setup a processing pipeline from last time I wanted to work on this. Here is what we have so far.

3:45AM. Here is the plan. All the log entries are in a list called entries, which I will now sort and split by IP.

4:15AM. Done. Though I have to cleanup the output some more.

Available on

We are proud to announce that the Concise MATH & PHYSICS Minireference is now available on the book store. After five years of low intensity work and two years of high intensity work, the book has reached a sufficiently quality in the writing, content and narrative flow so that we are ready to show it to the world.

Freshman-level math and physics in 300 pages.

We at Minireference Co. are here to fix the textbook industry.

December launch

I have been promoting and selling the book for the past two weeks art McGill and I have received a lot of good feedback from students. There is no point in thinking about business ideas — you have to go out and talk to clients. In just two weeks, I now have a title (thanks to my friend Adriano), a product line (I made a mechanics only version too) and a good idea of which pitches work and which do not.


NO BULLSHIT guide to MATH & PHYSICS. In just 300 pages, this book covers Precalculus, Mechanics, Calculus I (derivatives) and Calculus II (integrals). All the material is explained in a clear conversational tone. 100% Math and Physics, No filler.

We sold out today. Let’s see what happens tomorrow.