Programming questions that are significantly affected or best defined by the underlying mathematics of the problem.

learn more… | top users | synonyms

9
votes
6answers
3k views

Web Developer and Math [duplicate]

I have just learned HTML/CSS and I practice everything I read to make it more understandable to me and I really enjoy it. My goal is to be a Modern Web Developer both front and back-end, so I won't ...
5
votes
1answer
201 views

Bin sorting problem - Please help categorize

I have a problem I am developing a solution for and currently I solve it with a brute force solution that checks all possibilities. It works for small numbers of bins but I'd like to work with a ...
13
votes
2answers
477 views

Trying to understand the 2N lnN compares for quicksort

I was going through the analysis of quicksort in Sedgewick's Algorithms book. He creates the following recurrence relation for number of compares in quicksort while sorting an array of N distinct ...
0
votes
1answer
428 views

Sum of divisors of numbers of the range ~ 10^6

I was trying to find the sum of divisors of numbers upto 106. The test cases are like of the order of 105. I have done some pre processing like int divisors(int num) { int sum=0; for(int ...
0
votes
3answers
332 views

Using Power of 2 numbers to represent types

Let's say that we have some values, represented by power of 2: TYPE_1 = 1 TYPE_2 = 2 TYPE_3 = 4 TYPE_4 = 8 ... I need to store some of these types in one value. Example: To represent TYPE_1 with ...
0
votes
1answer
377 views

Python — Time complexity of built-in functions versus manually-built functions in finite fields

Generally, I'm wondering about the advantages versus disadvantages of using the built-in arithmetic functions versus rolling your own in Python. Specifically, I'm taking in GF(2) finite field ...
15
votes
4answers
911 views

Documenting mathematical logic in code

Sometimes, although not often, I have to include math logic in my code. The concepts used are mostly very simple, but the resulting code is not - a lot of variables with unclear purpose, and some ...
4
votes
2answers
820 views

Array Multiplication and Division

I came across a question that (eventually) landed me wondering about array arithmetic. I'm thinking specifically in Ruby, but I think the concepts are language independent. So, addition and ...
0
votes
0answers
93 views

What kind of maths do I need to become an excellent programmer [duplicate]

I am looking to become a app/video game developer or a website developer. What kind of maths do I need to know and do I have to know it well. Do I need to know calculus, statistics and modeling, what ...
5
votes
2answers
664 views

Does learning to play an instrument improve programming ability? [closed]

I've seen plenty of questions asking if listening to music boosts productivity, etc. but I haven't been able to find one about performing music. Learning to play the piano has been on my to-do list ...
3
votes
1answer
218 views

Finding maximum number of congruent numbers

Let's say we have a multiset (set with possible duplicates) of integers. We would like to find the size of the largest subset of the multiset such that all numbers in the subset are congruent to each ...
1
vote
0answers
255 views

Optimization algorithm, how to develop this problem

I have a situation where I would like your input and think over / solve algorithm. The specs There are inventories with a specified amount of capacity. 'X (width) and Y (time)' creates ...
5
votes
1answer
263 views

What is the difference between a combinator and function chaining?

So from what I've read about combinators I can't quite tell how they're different from simply chaining function calls. I know I must be missing something but I'm not figuring out what I'm missing. I ...
1
vote
1answer
212 views

Pairwise testing, not possible to say which combinations is faulty?

Let's say I have 4 (A,B,C,D) parameters with 3 possible values, also 81 unique combinations. With e.g. orthogonal array, I will end up with 9 test cases, each combining 3 pairs. But that means that if ...
2
votes
4answers
105 views

Find how the data has been processed

Well this has been a question I have puzzled about for a long time: Suppose I have a dictionary of input:output like: This {2: 6, 5: 15, 20: 60, 26: 78, ... 982: 2946, 997: 2991} where ...
2
votes
2answers
499 views

Transform math formula into code (line-line intersection)

I'm having hard times transforming a math formula to code. I can solve it on the paper easily, but it's hard for me to bring it into code form. Is it generally possible to bring a math formula ...
3
votes
4answers
994 views

Is there such a thing as truly random? [closed]

I saw a video about random numbers and how the programmer in that video was talking about computers generating pseudo random numbers and that they are not really random. I knew about this. Then he ...
0
votes
3answers
250 views

algorithm to create all possible column vectors of size N containing only ones and zeroes [closed]

I am a mathematics student and am just starting to learn about programming. I am stuck on a particular program I am trying to write for fun. I want to find an algorithm to create all possible column ...
2
votes
2answers
3k views

Closest Point of Approach (CPA) mathematical formula in ship radar

I was recently searching for the mathematical formula to find closest point of approach (CPA) between one ship and another ship. I need to apply the formula in my radar ship program and I can't find ...
4
votes
3answers
285 views

Customer Requirements Contains Equations that Cancel to Nothing

I have a project where the customer requirement specifies a report and contains mathematical equations for the contents of some of the columns on that report. One of the columns on this report is a ...
2
votes
7answers
802 views

Is (1/(1/x)) always a perfect round trip?

Is the following guaranteed to return true for all numerical and non-zero values of x? bool IsRoundTrip(double x) { double y = 1 / (1 / x); return x == y; } What conditions would cause a ...
0
votes
2answers
184 views

Tracking scientific error when working with floating-point numbers

Background I hate the way .Net/IEEE-754 handles equality of floating-point numbers (FPNs) (i.e. double, float). It requires the programmer to be prescient with respect to the yet-to-be-determined ...
3
votes
3answers
3k views

what is a efficient way to find repeating decimal

I am trying to find a efficient algorithm in Java to find the repeating decimal part of two integers a and b where a/b. eg. 5/7 = 0.714258 714258.... I currently only know of the long division ...
2
votes
3answers
298 views

strategies for dealing with machine epsilon

Say you have a situation where you divide and then multiply a float, and you need to guarantee that it survives macheps (ie multiplication output equals division input). What are known strategies for ...
0
votes
1answer
290 views

I'm trying to create a visual representation of something, but I don't know what words to use, so I'll try to describe it

My project team is making a site that will use reddit style voting to track users' opinions on various issues, and use the data to create a "heat map". I say heat map in quotes because I'm not sure ...
3
votes
2answers
139 views

Randomness of wrapped RNG

There are plenty of questions around regarding random number generation, but I couldn't find anything that exactly matched my question. Apologies if I missed one. Most random number generators in ...
0
votes
1answer
231 views

Algorithm to detect a CLICK within Square range

It might be a simple question but I am looking for optimal solution. I will have numbers printed on a screen and I will be aware of coordinates. Numbers/Symbols will have 4 points(Square) to define ...
10
votes
5answers
763 views

Interview puzzle on traveling on a line segment

Here's an interesting question I came upon: Let's just say on a number line of length M, where 0 < M <= 1,000,000,000, you given N (1 < N <= 100,000) integer pairs of points. In each ...
2
votes
1answer
114 views

Turning n-dim points into m-dim where m<n and where point-to-point distance deviation is minimized

I want to apply k-means clustering to a (sparse) adjacency graph. For this I need to assign the nodes to a position in an euclidean space. Trivially I can do this by having a space with as many ...
0
votes
1answer
145 views

How to do scalar multiplication and matrix inverse when variables are of size 1000 bits?

I am doing arithmetic operations on really huge numbers. For example, I am given six variables, a_{11}, a_{12}, a_{21}, a_{22}, x_1, and x_2. Although the above are math terms, these six variables ...
2
votes
1answer
1k views

Randomly Generate Points in a Spiral Motion using Javascript

So I have a javascript program that currently gets random points, it generates a random x,y,z value around the center point, within the radius r var maxArms = 3; var i = 0; var color = []; ...
-1
votes
1answer
2k views

How to get audio spectrum analysis? [closed]

I need to find or create a tool that analyzes the audio spectrum of a sound file (like a .wav or .mp3). I need to output the "volume" or power of x number of frequency bands and output the data as ...
2
votes
1answer
3k views

Find the new coordinates using a starting point, a distance, and an angle

Okay, say I have a point coordinate. var coordinate = { x: 10, y: 20 }; Now I also have a distance and an angle. var distance = 20; var angle = 72; The problem I am trying to solve is, if I want ...
3
votes
3answers
692 views

Date calculation algorithm

I'm working on a project to schedule a machine shop, basically I've got everything covered BUT date calculations, I've got a method called schedule (working on PHP here): public function ...
0
votes
4answers
655 views

Separating merged array of arithmetic and geometric series [closed]

Given an array of positive integers in increasing order. Separate them in two series, an arithmetic sequence and geometric sequence. The given array is such that a solution do exist. The union of ...
1
vote
3answers
2k views

Calculating 3d rotation around random axis

This is actually a solved problem, but I want to understand why my original method didn't work (hoping someone with more knowledge can explain). (Keep in mind, I've not very experienced in 3d ...
25
votes
9answers
7k views

How to check if 4 points form a square?

Assume I have 4 points (they are 2-dimension), which are different from each other, and I want to know whether they form a square. How to do it? (let the process be as simple as possible.)
7
votes
3answers
518 views

how to programtically build a grid of interlocking but random sized squares

I want to create a two dimensional layout of rectangular shapes, a grid made up of random sized cubes. The cubed should fit together and have equal padding or margin (space between). Kind of like a ...
26
votes
4answers
2k views

Can you use Pi as a crude random number generator?

I recently saw this question over at math.SE. It got me thinking. Could Pi be used as a crude random number generator? I mean the results are well known(how long has pi been computed to now?) but, Pi ...
32
votes
15answers
4k views

Why use other number bases when programming

My coworkers and I have been bending our minds to figuring out why anyone would go out of their way to program numbers in a base other than base 10. I suggested that perhaps you could optimize longer ...
5
votes
4answers
245 views

Should Equality be commutative within a Class Hierachy?

It is easy to define the Equals operation in ways that are not commutative. When providing equality against other types, there are obviously situations (in most languages) were equality not being ...
4
votes
1answer
301 views

What's the normal way machine-learning algorithms are integrated into normal programs?

I'm currently taking a machine learning course for fun, and the course heavily focuses on Matlab/Octave to write the code. One thing mentioned in the course is that, while Matlab/Octave are great for ...
-2
votes
5answers
2k views

Differential and integral calculus for programmer [duplicate]

Possible Duplicate: Where is the application of Calculus(of continuous quantities) in Computer Science or programming How can calculus and linear algebra be useful to a system programmer? ...
0
votes
3answers
121 views

Working with vectors and transformations

I am going to write an graphical 2D application that allows user to create polygons and transform them through transformation such as rotation an so on. I was hoping someone can give pro and cons ...
3
votes
3answers
975 views

Algorithm to calculate trajectories from vector field

I have a two-dimensional vector field, i.e., for each point (x, y) I have a vector (u, v), whereas u and v are functions of x and y. This vector field canonically defines a set of trajectories, i.e. ...
1
vote
1answer
184 views

What resources are there for facial recognition [closed]

I'm interested in learning the theory behind facial recognition software so that I can hopefully implement it in the future. Not just face tracking, but being able to recognize individuals. What ...
8
votes
1answer
2k views

Are there studies on what programming does to the brain? [closed]

Are there studies on what effects have programming languages on the brain or for that matter any other artificial languages in general, like mathematics ? Speaking from my personal experience I feel ...
2
votes
2answers
258 views

Dealing with units in arithmetic operations (multiplication and division)

I need to design a function to perform the basic arithmetic operations that are addition (+), subtraction (-), multiplication (x), and division (/) between 2 numbers. That function takes 3 arguments: ...
5
votes
2answers
773 views

Fractional and Cartesian Coordinates

I have a set of fractional coordinates. I also have a rotation matrix that operates on cartesian coordinates. Does anyone know how I could convert my rotation matrix so I can operate on the ...
4
votes
3answers
1k views

What Discrete Mathematics topics should the average computer science student know?

I know that Discrete Mathematics is a pretty broad topic that's used in a number of fields but I was just wondering what are some of the topics from it that you would expect an average computer ...