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Ask HN: How did you learn math notation?

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Re: Ask HN: How did you learn math notation?

#41

Post by [deleted] »

gspr wrote: post #34
rullopat wrote: post #19

Earlier quoted context omitted.

Sorry I didn't mean to make you work for me, but it's a PDF and I didn't know how to explain better the position (maybe I should have told you the first formula on page X). For you it was a D, for me it was a triangle and I didn't get the meaning of that Dt. Maybe it's just a too advanced paper for my knowledge.

I'll use this as an example for the point I'm trying to make in my comment https://news.ycombinator.com/item?id=29341727 Please don't take this the wrong way. It is not meant to be demeaning, and it is not meant to be gatekeeping (quite the contrary!). But: If you do not know what a derivative is, then learning that that symbol means derivative (assuming that it does, I have not actually looked at what you link to) w…

[deleted]

Re: Ask HN: How did you learn math notation?

#42

Post by pfortuny »

rullopat wrote: post #11
ColinWright wrote: post #2

I think a real problem in this area is the belief that there is "one true notation" and that everything is unambiguous and clearly defined. Yes, conventions have emerged, people tend to use the same sort of notation in a given context, but in the main, the notation should be regarded as an aide memoire , something to guide you. You say that you're struggling because of "the math notations and zero explanation of it i…

I was trying to grasp some of the papers linked in the Valhalla DSP block, for example this one: http://www2.ece.rochester.edu/courses/ECE472/resources/Paper... There is a formula with a triangle and I don't get what's that about, for example.

You probably want to try and read Courant-Johns Calculus (I forget the exact title).

Re: Ask HN: How did you learn math notation?

#43

Post by phtrivier »

Do you mean all the introductory mathematics books you tried fail to properly explain the notation ?

Or that the notation differs from books to books ?

(In my case, I learned the notation via French math textbooks, and in the first day of college/uni we litteraly went back to "There is a set of things called natural numbers, and we call this set N, and there is this one thing called 0, and there is a notion of successor, and if you keep taking the successor it's called '+', and..." etc..

But then, the French, Bourbaki-style of teaching math is veeeeeeeery strict on notations.

Re: Ask HN: How did you learn math notation?

#44

Post by wenc »

I learned it by asking peers in grad school what stuff meant. And working through the math myself (it was a slog at first) and then writing stuff out it in LaTeX. When one is forced to learn something because one needs to take courses and to graduate, the human brain someone figures out a way.

A lot of it is convention, so you do need a social approach - ie asking others in your field. For me it was my peers, but these days there’s Math stack exchange, google, and math forums. Also, first few chapters of an intro Real Analysis text is usually a good primer to most common math notation.

When I started grad school I didn’t know many math social norms, like the unstated one that vectors (say x) were usually in column form by convention unless otherwise stated (in undergrad calc and physics, vectors we’re usually in row form). I spent a lot of time being stymied by why matrix and vector sizes were wrong and why x’ A x worked. Or that the dot product was x’x (in undergrad it was x.x). It sounds like I lacked preparation but the reality was no one told me these things in undergrad. (I should also note that I was not a math major; the engineering curriculum didn’t expose me much to advanced math notation. Math majors will probably have a different experience.)

Re: Ask HN: How did you learn math notation?

#45

Post by fsloth »

I think good first resource would be the book and lecture notes in an introductory university course treating the specific domain you are interested in because often lots of things in notation are domain specific. Lots of good open university lectures out there, if not sure from where to start the MIT open courseware used to be a good first guess for accessing materials.

As a sidenote I have MSc in Physics with a good dollop of maths involved and I am quite clueless when looking at a new domain so it's not as if university degree in non-related subject would be of any help...

Re: Ask HN: How did you learn math notation?

#47

Post by amitkgupta84 »

First, just to state the obvious, if you can accurately describe a notation in words, you can do an Internet search for it.

When that fails, math.stackexchange.com is a very active and helpful resource. You can ask what certain notation means, and upload a screenshot since it’s not always easy to describe math notation in words.

If you don’t want to wait for a human response, Detexify (https://detexify.kirelabs.org/classify.html) is an awesome site where you can hand draw math notation and it’ll tell you the LaTeX code for it. That often gives a better clue for what to search for.

For example you could draw an upside down triangle, and see that one of the ways to express this in LaTeX is \nabla. Then you can look up the Wikipedia article on the Nabla symbol. (Of course in this case you could easily have just searched “math upside down triangle symbol” and the first result is a Math Stackechange thread answering this).

Re: Ask HN: How did you learn math notation?

#49

Post by 734129837261 »

If math was a programming language, all mathematicians would be fired for terrible naming conventions and horrible misuse of syntax freedom.

Honestly, most math formulas can be turned into something that looks like C/C++/C#/Java/JavaScript/TypeScript code and become infinitely more readable and understandable.

Sadly, TypeScript is one of the languages that is attempting to move back to idiocy by having generics named a single letter. Bastards.

Re: Ask HN: How did you learn math notation?

#50

Post by cabalamat »

ColinWright wrote: post #2

I think a real problem in this area is the belief that there is "one true notation" and that everything is unambiguous and clearly defined. Yes, conventions have emerged, people tend to use the same sort of notation in a given context, but in the main, the notation should be regarded as an aide memoire , something to guide you. You say that you're struggling because of "the math notations and zero explanation of it i…

> I think a real problem in this area is the belief that there is "one true notation" and that everything is unambiguous and clearly defined.

One main cause for this belief is that in a programming there is one true noation (or rather, a separate one for each language) that is unambiguous and clearly defined.

I dislike maths notation as I find it lacks rigour.

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