Tuesday, May 1, 2012

Are Good Programmers Good at Maths

I was reading an interesting argument on SO. The topic of discussion was that conventional wisdom suggests that good programmers are also good at math...Or that the two are somehow intrinsically linked. Many programming books I have read provide many examples that are solutions to math problems, or are somehow related to math as if these examples are what make sense to most people.

So the question is: do you have to be good at math to be a good programmer?

It all depends on what you want to do as a software developer.

If you want to go into graphics, you need a strong background in geometry, linear algerbra, matrix tranformations, (physics wouldn't been terrible either) etc. If you want to go into SQL or other types of database programming, logic (proofs, inference laws, etc) and Discrete Mathematics (maybe even lambda calculus) are all necessary.

As far as being a programmer in the business world goes, I would say that the answer is NO. You can become a great programmer without knowing advanced mathematics. When you do end up having to deal with math, the formulas are usually defined in the business requirements so it only becomes a matter of implementing them in code.

How about a Math mindset?

Most people think of math as doing arithmetic or memorizing arcane formulas. This is like asking if you need perfect spelling or an extraordinary vocabulary to be a good writer.Writing is about communication, and math/programming is about the process of clear, logical thinking (in a way that you can't make mistakes; the equation doesn't balance, or the program doesn't compile). Specifically, that logical thinking manifests in:

  • Ability to estimate / understand differences between numbers: O(n^2) vs O(lg(n)), intuitive sense of KB vs MB vs GB, how slow disk is compared to RAM. If you don't realize how tiny a KB is compared to a GB you'll be wasting time optimizing things that don't matter.
  • Functions / functional programming (is it any coincidence that the equation f(x) = x^2 is so similar to how you'd write that method? The words "algorithm" and "function" were around in the math world far before the first computer was born :-))
  • Basic algebra to create & reorder your own equations, take averages, basic stats

So, I'll say you need a math mindset, being able to construct & manipulate mental models of what your program is doing, rather than a collection of facts & theorems. Certain fields like graphics or databases will have certain facts you need also, but to me that's not the essence of being "good at math".

I'll quite happily admit I've never particularly liked maths or been good at it (I actually graduated with a degree in Political Science!) and have worked as a professional developer for over 18 years now. I develop mostly web applications, which rarely require that much maths. More important is the ability to think logically, be able to break problems down into chunks and have a wide understanding of the various technologies and frameworks involved.

As a programmer you are much more likely to have to implement an existing algorithm than devise an entirely new one. Need to work out, say, compound interest? You don't need to figure it out yourself, just look-up the formula and apply it. Most of the problems have already been solved, you just need to know how to implement the solutions in your language of choice. That's not to say that being good at maths wouldn't be an advantage; it's just that it isn't totally essential.

When I was at school in the mid 80's when home computers where not very common I often wrote programs to solve my maths homework. I often couldn't do it in my head, but I could apply whatever formula was required as a software routine. You don't need to be another Pythagoras to work out the longest side of a right-angled triangle, you simply need to be able to code up a² + b² = h² in your language of choice.


You don't have to be good at math. However, you have to be good at logic, and problem solving. Some would argue that people who are good at logic and problem solving are usually good at math also. I would say that it really depends on the type of math. You can be terrible at calculus (like me), and still be a good programmer (like me). But if you have trouble with Discrete Math and Set Theory, you would probably find a lot of aspects of programming quite hard.