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Ask HN: How can I learn to read mathematical notation?

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Re: Ask HN: How can I learn to read mathematical notation?

#51
1. Try to get a mentor.

During my time as a PhD student in philosophy, I had the luck of having a mathematician and physicist turned philosopher as my supervisor. He helped me a lot in understanding notation and improving my own mathematical writing style (~ getting silly notation ideas playing around with LaTeX out of my head).

Notation heavily relied on conventions and these differ from field to field. Mathematicians are usually very clear and define everything. They have to be easy to understand, because what they are talking about gets very complicated very fast. Unfortunately, in other areas like logic-oriented theoretical CS there is an unhealthy focus on 'notational precision' (plus shortcuts, making things worse) rather than being understood that can make papers rather incomprehensible at first.

2. Look for textbooks with good mathematical prose.

Get some recommendations. Some good introductory books are relatively short, self-contained, define everything, and avoid symbols in favor of English in many places. Try to get one of those in the area you're interested in.

3. Check your reading style. (kind of obvious advice that is often given, but maybe still helpful)

You may be reading the texts in the wrong way. I did that very often and occasionally still do. Reading a mathematical text takes way more time than any other text and requires active participation. Do the exercises and stop every so often to check your understanding. Constantly use pen and paper and check everything. Draw diagrams.

Re: Ask HN: How can I learn to read mathematical notation?

#52

I love how there are these two parallel threads going in HNville: (1) COLLEGE SUCKS BURN IT DOWN and (2) "I'd like to learn complex things like machine learning and math that take more than reading 5 blog posts to master, how do I do it"? Sometimes this place just cracks me up. I honestly think the answer is pretty simple: go to college. It doesn't have to be expensive. Take a community college course in calculus or…

Just because you choose to believe you need to be fed your information doesn't mean others do. I've tutored people carrying the thoughts you're expressing ("I need someone to teach me this because I'm not smart enough to learn it on my own"). The quickest way to success with them was shattering that myth. I did it by talking to them about their feelings/beliefs and helping them figure out practices for changing their…

It's not about being "fed information". It's the reality that being around a motivated group of peers confers real advantage.

I look at the history of art (e.g. Impressionists), YC, winning athletics programs, Silicon Valley, or just about any well-regarded academic department as evidence. These places don't do well just because they select the best, they also MAKE the best by creating an environment that fosters it.

Re: Ask HN: How can I learn to read mathematical notation?

#53

I love how there are these two parallel threads going in HNville: (1) COLLEGE SUCKS BURN IT DOWN and (2) "I'd like to learn complex things like machine learning and math that take more than reading 5 blog posts to master, how do I do it"? Sometimes this place just cracks me up. I honestly think the answer is pretty simple: go to college. It doesn't have to be expensive. Take a community college course in calculus or…

> I don't know any way I'd have learned all the complex topics in math, stats, probability, etc., I did without attending a big 10 engineering school

This is something the MOOC crowd often overlook. It's based on a misunderstanding of what a university gives you: university entry doesn't grant you access to some members-only club where they hide away the knowledge to keep it from the plebs (ignoring the open access movement, at least). Instead it grants you access to an environment in which you can learn effectively.

The idea that MOOCs will threaten the existence of universities is absurd. It's already possible to get access to the sum of human knowledge without being enrolled at a university. It's always been possible. They're called books.

But this stuff is hard, and attending a high-quality institution gives you a huge advantage in learning the material, compared to being self-taught. MOOCs may grant everyone access to lectures, but just as important is learning with high-quality peers. A MOOC is not the equivalent of being in a class with other smart and well-motivated students.

Again, it's always been possible to learn this stuff independently, but your odds of succeeding are far lower that way. It's great that we have lots of freely available learning material online, but I really don't see that MOOCs are going to turn the world on its head the way some people seem to think.

I'm ignoring accreditation here, of course. If you want to be a surgeon, you obviously do not have the option of teaching yourself, but in terms of learning maths/technology (and assuming knowledge - and not a certificate - is your goal), books have always been there. MOOCs are books++, not universities--. (With apologies to the pedants who might prefer the pre-positional operators.)

Re: Ask HN: How can I learn to read mathematical notation?

#54
post #50

Other people have listed great books and resources. What I don't see, however, is to ask a friend. Find someone who is familiar with the notation, if not the material, and ask questions. You'll likely get a more clear answer.

You say:

> What I don't see, however, is to ask a friend.

From https://news.ycombinator.com/item?id=18510564 :

> ... get a few examples, and ask some friends, colleagues, or on-line forums ...

Re: Ask HN: How can I learn to read mathematical notation?

#56
I think you've got this backwards. You don't need to understand the notation, you need to understand the math. If you don't understand the notation then you probably don't understand the math in the first place so learning notation won't help. Learning how a matrix is written is useless without understanding what a matrix is.

You need to find out exactly what type of math is used in the paper and learn that. Learning notation will come along with that. If you're interested in machine learning then you should probably start with:

* Proofs and logic (a general requirement to understanding math) * Linear algebra * Statistics * Some multi-variable calculus

Re: Ask HN: How can I learn to read mathematical notation?

#57

here's a dirty seceret: we (people that have mathematical training) don't read the notation very closely either. it's very much like reading code: i don't look very closely unless there's a pattern i don't recognize or one that's broken. so ironically reading notation is about ignoring notation :) the problem for you is that you simply haven't had enough exposure to know what the "patterns" are and hence don't have t…

I was a college math major, and I can't read math the way I can read text or even sheet music. I familiarized myself sufficiently by writing out my own derivations and treating the textbook as a reference while working the problems. The act of writing the stuff out and manipulating it with my hands is how I learned it.

I think that’s how everybody does it with stuff that’s new to them.

After enough slow progress (“one page per day” can easily be speed reading), parts of what you are reading become what mathematicians call ‘trivial’, and your reading speed of similar texts increases.

I think there’s an analogy with ‘reading’ a chess position. If you watch the ongoing Carlson-Caruana match on https://youtube.com/watch?v=DgvqBjrusIA, you’ll notice that the commenters can easily go through three or four variants in a minute, and call one position an obvious draw, another clearly winning, etc. The reason they can do that is that they have looked at thousands of similar positions, and remember the essential parts of them.

Re: Ask HN: How can I learn to read mathematical notation?

#58
Could you give some examples of notation that you struggled to understand, and explain what about it you find confusing?

One difficulty of notation is that the hierarchy of abstraction builds dizzyingly quickly, and soon you're manipulating symbols that generalise a whole classes of structures that were themselves originally defined in terms of lower-level abstractions. When this becomes overwhelming, it usually means that I didn't give my understanding of the lower levels long enough to settle and mature.

Concise notation and terminology is only useful if the underlying ideas are organised neatly in your mind, and the best way I've found of achieving this is to study a subject obsessively for some time, then put it away for a few weeks, and then go back and try to see the big picture and find out where it doesn't fit together by trying to derive the main results from scratch. Then I start again and fill in the blanks. After a few years things begin to make sense, but this process takes time and it's difficult and tiring (or at least that has been my experience of it).

In order to read research papers fruitfully it's crucial that you understand the basics well, and the best way to do that is to work through books aimed at undergraduates or young graduates. People don't read foreign literature by jumping straight in and looking up every word and every grammatical construction as they go. They become familiar enough with the language by reading easier texts until the language is no longer an obstruction - then they're free to appreciate what's happening at a higher level. The same for driving: you wait until you're comfortable operating the car mechanically before you drive on busy roads. The same, also, for mathematics.

It is not at all unusual to to find notation and technical terminology tiring. Everyone does to some extent. I hate it. But it's necessary.

Some resources I found useful:

Naive Set Theory by Paul Halmos. One of the great mathematical expositors, Paul Halmos here describes the fundamental language of mathematics: set theory. This is a book for people who want to understand enough set theory to do other parts of mathematics without obstacle.

How to Prove It by Daniel Vellemen. A nice introduction to logical notation and common proof structures, aimed at helping incoming maths students to become comfortable with the basics of formal language and notation.

Anything by John Stillwell. Stillwell is an inspiring teacher who insists on including the practical and historical motivations for the abstractions we use (this is, sadly, rare for modern teachers of mathematics). If you find yourself wondering why people cared about a problem enough to solve it, Stillwell might be able to help.

I suspect you'll also need resources on linear algebra (Halmos has 'Finite Dimensional Vector Spaces') and analysis but I'm not sure as I don't work in machine learning. I just sort of learnt linear algebra as I went and I avoid analysis as much as a supposed mathematician can. (context: my undergraduate degree was in economics and didn't carry much mathematical content other than some basic linear algebra - now I'm a graduate student in mathematics and computer science who uses a lot of category theory and abstract algebra. The transition was painful. Really painful.)

Re: Ask HN: How can I learn to read mathematical notation?

#59
Some things that help me a lot, in order of helpfulness (for me):

* Read formulae aloud, using natural languages for symbol names (it is not "sigma of k from i to j", it is a "summation of terms with k from i to j").

* Look at the proofs/construction of these formula and understand them.

* Look at translations of the formulae (applied physics textbooks, more often program code); sometimes it helps to work your way back to the formula from a starting point you are more comfortable with.

* Understand that making up symbol meanings ad hoc is one of the perks of mathematicians - you can find fights within a single math department on how notation should be.

Re: Ask HN: How can I learn to read mathematical notation?

#60

I think the lazy and somewhat cynical answer is also the most accurate: learn the mathematics.

Indeed. I was thinking that the question is in some ways like asking "How can I understand the chemical symbols used in these equations". One could perhaps memorise that 'Na' is Sodium and H is Hydrogen but without knowing what they are and how they behave etc. an equation in isolation is meaningless and won't help to understand the reaction.
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