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

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-6
votes
0answers
32 views

How to get precise Math.exp() in j2me [closed]

I am using j2me and I need to get quite precise exp() for values up to 4. Problem with the j2me is that it's Math library doesn't have pow() and exp() method. To solve this, I just used this method to ...
0
votes
1answer
110 views

Are there compilers which optimize the use of mathematical functions?

Today while programming I stumbled upon the following question - are there any compilers which optimize based on mathematical assumptions? For instance in cases like unsigned int i,b; (i,b not ...
7
votes
2answers
130 views

Should `Vector<float>.Equals` be reflexive or should it follow IEEE 754 semantics?

When comparing floating point values for equality, there are two different approaches: NaN not being equal to itself, which matches the IEEE 754 specification. NaN being equal to itself, which ...
3
votes
1answer
1k views

Where should I start learning math with regards to programming [duplicate]

I've created several systems already, a web based menu system, a payroll system and I am currently developing a patient administration system, I know java,C,C++ C#, javascript PHP and other ...
1
vote
1answer
43 views

How to handle user created expressions in application

In our application users can enter custom expressions to calculate certain things. For instance they can specify an invoice and define a number of lines for cost calculation. Example for a course ...
2
votes
2answers
74 views

From a set of rules, derive the implications? [closed]

I've only just become interested in this domain, so sorry if I'm not using the correct terminologies. What I want is the following: Say I have a set of rules (or constraints), I want to derive some ...
5
votes
2answers
295 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 ...
2
votes
0answers
78 views

Program to select N integers with constraints [closed]

I need to write a program which takes 4 inputs as follows N = The number of integers to be generated (10 < N < 10000) Start = The minimum value of the integers (100 < Start) End = The ...
1
vote
1answer
533 views

Number of parallel lines in a given set of lines [closed]

I am given N lines, i.e, I am given a,b,c for N lines. And each line is of the form ax + by + c = 0. I need to find out the maximum number of lines that are parallel to each other. For this, first I ...
2
votes
2answers
6k 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 ...
3
votes
3answers
438 views

Why is the “period of a (pseudo)random number generator” important?

I've been trying to understand (pseudo)random number generator code from various sources and the concept of the period continues to elude me. To satisfy the minimum level of understanding, I've tried ...
4
votes
2answers
90 views

Should a generic vector class allow non-finite doubles as values?

I am currently writing an immutable multipurpose vector class in Java that essentially wraps a double[]. The class will be part of a game library, used to calculate entity positions, physics, pixel ...
17
votes
1answer
2k views

Why does Math.min work with a one element array

According to MDN Math.min accepts only numbers, and if one of the arguments is not a number, it'll return NaN. It's true that if we pass an array with multiple numbers we get NaN, like this: ...
24
votes
11answers
4k views

Why do we still use floats? [duplicate]

I understand why floats served a purpose in the past. And I think I can see why they're useful in some simulation examples today. But I think those example are more exceptional than common. So I ...
11
votes
3answers
4k views

Handling extremely large numbers in a language which can't?

I'm trying to think about how I would go about doing calculations on extremely large numbers (to infinitum - intergers no floats) if the language construct is incapable of handling numbers larger than ...
29
votes
10answers
7k views

Why is Math.Sqrt() a static function?

In a discussion about static and instance methods, I always think, that Sqrt() should be a instance method of number types instead of a static method. Why is that? It obviously works on a value. // ...
3
votes
2answers
141 views

C# Abstract math classes from libraries

I'm currently writing a library that abstracts 3D rendering and uses SharpDX and OpenTK as graphics libraries. The problem is that OpenTK and SharpDX have their own implementations of Vector2, Matrix, ...
2
votes
2answers
159 views

What are the advantages of matrix multiplication over individual variables (graphics)?

I am learning OpenGL and the tutorials (1, 2) I'm reading teach me that to scale/rotate/translate an object you have to know matrix multiplication. Why? Instead of 3x3 matrix you can use 6 floats: ...
2
votes
3answers
168 views

How does google calculate travel distance/time

I've been working for quite a while now on a service that generates optimal routes for a given set of addresses and vehicles (Vehicle routing problem / traveling salesman problem). Now it's all ...
4
votes
1answer
347 views

Transpose a matrix without a buffering one

How is it possible to transpose a MxN matrix without using a "buffering" matrix? In the latter case it's easy and quite the "classic" approach... Given a matrix[M][N], I would like to put it into a ...
3
votes
1answer
846 views

What will generate an adjacency matrix file with a specified topology for me?

I am writing an application that takes some file specifying an adjacency matrix and uses this to construct a graph (in this case, a directed social network). What I would like to do is specify the ...
2
votes
4answers
152 views

What is the best data model to represent mathematical range (in database, xml, json…)?

For example, greater or equal to 50 and smaller than 100 (>=50 && < 100) smaller than 10 or greater than 40 (<10 || >40) I have been thinking about how to represent ...
-2
votes
1answer
60 views

Computer Algorithms for Polynomial Regression [closed]

Given a data set of arbitrary size, what algorithm would be appropriate for performing the polynomial regression on the data set such that the highest degree of the polynomial is n? If there are ...
20
votes
11answers
1k views

How is fundamental mathematics efficiently evaluated by programming languages?

As I get more and more involved with the theory behind programming, I find myself fascinated and dumbfounded by seemingly simple things.. I realize that my understanding of the majority of fundamental ...
15
votes
1answer
7k views

Treating a 1D data structure as 2D grid

I am working with a native class that represents a 2D image as a 1D array. If you want to change one pixel, for example, you need to now how to derive the index from the x,y coordinates. So, let's ...
3
votes
1answer
140 views

why adding a vertex in a graph represented using an adjacency matrix takes O(|v|^2) time complexity?

Adding a vertex in a graph that is represented using an adjacency matrix takes O(|v|^2) time complexity according to http://bigocheatsheet.com/ (graph operation > adjacency matrix > add vertex). But ...
1
vote
1answer
44 views

How an add vertex operation could be performed in constant time for a graph represented using adjacency list?

Adding a vertex in a graph that is represented using an adjacency list takes O(1) time complexity according to http://bigocheatsheet.com/ (graph operation > adjacency list > add vertex). It is said ...
1
vote
4answers
468 views

What is the “correct” way to store functions in a database?

Note: Yes, I know that storing functions in databases should be punishable by law. We are developing a financial web application using PostgreSQL, Sinatra and AngularJS. As you may have guessed, a ...
16
votes
1answer
510 views

In what programming language did the use of the percent sign (%) to mean modulo/remainder originate?

In what programming language did the use of the percent sign (%) to mean modulo/remainder originate? This previous post1 explains that the symbol % was likely chosen because it includes a slash, ...
4
votes
1answer
197 views

Why does Java define BigInteger / BigDecimal values of 10?

Question perhaps slightly left of field - but I'm curious as to the logic behind why Java's BigInteger/BigDecimal classes feel the need to define a constant of TEN? Example taken from ...
3
votes
0answers
320 views

Fast fixed-size (256 bit) integer modulo/division

What is the fastest way to divide two 256-bit integers? They are represented as an array of 26-bit words, each stored in 32-bit integers. I have access to a 64-bit type if that's useful. It seems ...
3
votes
4answers
4k views

TEA algorithm constant 0x9e3779b9 said to be derived from golden ratio, but the golden number is 1.618?

I'm trying to understand a constant 0x9e3779b9. What kind of data is this? It's not binary, not decimal, what is this? It's a constant used on the TEA algorithm. It says it's derived from the golden ...
0
votes
1answer
37 views

Error handling in math library functions

When writing a library function, such as double getAvg(double[]); how should one handle the empty array? (Note that, mathematically speaking the avg of an empty set is undefined.)
3
votes
1answer
198 views

When writing a math library, will operator overloading maintain OOP?

I want to make a fairly complicated mathematical library for a personal project and then have a visualization/GUI to go along with it to demonstrate the maths - nothing hardcore like topology but just ...
6
votes
5answers
276 views

Hamming Distance using a dictionary

First time poster. I'm currently programming a hamming distance program using a dictionary. So if we start with the word "cat" and we want to transform it into "dog", the sequence is ...
29
votes
5answers
12k views

Return random `list` item by its `weight`

I have, for example, this table +-----------------+ | fruit | weight | +-----------------+ | apple | 4 | | orange | 2 | | lemon | 1 | +-----------------+ I need to return random ...
2
votes
2answers
205 views

Algorithm and data structure to match groups of users (1-5 each) into 2 balanced sets of 5 users

I'm building a matchmaking queueing service for a 5v5 team-based game. I have a large set of users that are grouped into unique lobbies comprised of 1-5 users each. Each user has an integer based ...
0
votes
0answers
76 views

BCMath vs MySQL: performance

Scenario I am working on a web application that handles financial transactions, and my code will need to be reusable for everything from consumer carts to manufacturer/distributor shipments. The ...
4
votes
0answers
165 views

How can unums emulate IEEE's negative zero?

I am currently reading "The End of Error - Unum Computing" by John Gustafson (Youtube). What I am still not sure about is how the cases handled in IEEE by negatively signed zero are handled with ...
10
votes
2answers
5k 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 ...
10
votes
5answers
873 views

Interview puzzle on traveling on a line segment

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 pair, the first point represents where an object is currently ...
8
votes
3answers
2k views

What is the best way to keep track of the median?

I read a question, and I'm looking for input on how to solve it: Numbers are randomly generated and stored into an (expanding) array, How would you keep track of the median? There are two data ...
0
votes
1answer
59 views

Count amount of points for XY options (in poll) where options dont have equal amount of points

I have a code where I want to avoid using a for/each loop to count the amount of points options in poll have together. Reason is, every option has different ammount of points and I want to get number ...
0
votes
1answer
27 views

Generating New Media Content From Binary Patterns

At the most basic level, a digital media file (document, song, video, etc) is just a rather large pattern of 1's and 0's. We can say that for any given piece of digital media, there corresponds a ...
0
votes
1answer
83 views

Changing coordinate systems in python

I am working on a visual python program that is meant to model the orbit of an electron around the core of a Hydrogen atom. In order to avoid the singularity at r = 0 in the equation for coulomb ...
2
votes
2answers
216 views

How to iterate between these elements

I have an array of elements: int[] elem = new int[] {A, B, C}; I need to calculate the sum of ALL the combinations of those elements, where only some of the elements can be optionally selected. I ...
7
votes
1answer
2k views

Can one edit a built-in Python module?

I'm currently learning Python and I'm at the point in the book about using the Math library. I looked on the Python website and noticed the library was a bit scarce and am writing some more useful ...
33
votes
4answers
914 views

Why is negative zero important?

I'm confused about why we care about different representations for positive and negative zero. I vaguely recall reading claims that having a negative zero representation is extremely important in ...
-1
votes
1answer
183 views

How to selecting Teams with Minimum Difference between Knowledge Levels

For the below challenge from a programming site, I am bit confused. Problem Statement: A Professor of Physics gave projects to the students of his class. The students have to form a team of two for ...
2
votes
4answers
3k views

How to get from 1 byte to 2 bytes

We have 1 byte, which is 8 bits, which is 2^8. Now 2 bytes should be 2 * 1 byte, which is 2 * 2^8 = 2^9, but actually 2 bytes is 2^16. What am I missing here? It seems like 2 bytes isn't 2 * 1 byte, ...