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

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21
votes
4answers
329 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
0answers
29 views

Comparing and adding (math) integers in an array [closed]

Long time Front-End Dev, new-ish to core programming theories. I am trying to solve a problem, but mentorship to gain better language is needed to progress. Write a method to return the minimum # of ...
0
votes
1answer
60 views

Vector API, naming for element-wise multiply [closed]

I'm helping develop a 3D Vector class, which has common operations such as: v = v1.cross(v2) v = v1 * v2 - infix multiply for dot product. v = v1 + v2 - infix addition. v = v1.slerp(v2) - spherical ...
-1
votes
1answer
106 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 ...
1
vote
1answer
28 views

System for deducting velocity against sources pf gravity

Say I have a particle-based physics engine (which I do) that uses lots of particles with a x and y coordinate and velocity. These particles can also have a mass, which means that these particles (with ...
0
votes
1answer
58 views

Convert x and y velocity to x and y velocity relative to another point

The question I asked probably isn't very clear, so I'll explain. If I have an x and y velocity, where the y goes towards the bottom of the screen, and the x goes towards the right of the screen, how ...
1
vote
2answers
141 views

Line intersection detection algorithm

I'm trying to detect if a line drawn by the user intersects itself. I'm using a line intersection detection algorithm that goes through each waypoint of the line and checks if intersects with any ...
0
votes
0answers
48 views

Domain analysis for discrete values - ON and OFF points in these cases

Following my previous question (with great answer from Bart van Ingen Schenau), I noticed a discrepancy I could not wrap my head around: Bart mentioned that: The point ON the boundary is by ...
-1
votes
1answer
99 views

Algorithm to 'segment' a number into blocks of n?

I'm not sure how to word the title properly, but the problem goes something like this: I have 5 nodes, and node 0 is the "master". User inputs a number, e.g. 100 to the master. master "splits" the ...
1
vote
3answers
153 views

Domain analysis - why OFF points are inside of the domain when the border is open

I have asked on a few other sites, no response but it must be something silly as many authors mention in their books. Here is the best text I found: My ultimate question is: Why the OFF point lies ...
1
vote
0answers
163 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 ...
0
votes
2answers
133 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 ...
2
votes
1answer
190 views

Well defined mathematical operations for bearing (angle) class

I have written a class to represent bearings (angles with a nautical theme, and a specific normalisation range). In the program, it is necessary to perform some mathematical operations on them, so ...
4
votes
1answer
87 views

Mathematically correct A* heuristic / distance estimator for a latitude / longitude graph

I have a graph in which each node is a geographical point on the surface of the earth, defined by it's latitude / longitude coordinates. Correct ways to calculate the distance between two such points ...
0
votes
3answers
140 views

How do deal with angle wraparounds when comparing them?

Angle A is a degree angle that keeps increasing by increments and Angle B is the stopping point of Angle A (think 'Spin-the-bottle' where Angle A is the current angle of the bottle Angle B is the ...
1
vote
1answer
73 views

Algorithm to find the fewest number of values (from a set of values) where the sum equals a value (+ one more condition)

The simplest way to explain this is with an example. You're given then number 19 and you have a set of numbers to choose from: 1, 2, 3, 4, 6 When choosing values from the list (which can be ...
0
votes
0answers
27 views

Specific weight randomness based on a curve [duplicate]

I had a problem where I had a list of objects and I wanted the ones near the front of the list to "appear more" then the others when chosen randomly. There wasn't any specific weighting involved for ...
1
vote
1answer
75 views

Program to find Orthogonal Matrices

I have been trying to find orthogonal matrix of order n where first row will be given as 1/√n, 1/√n, .... n times. The second row will be a vector such that dot product of it with the row above and ...
0
votes
5answers
340 views

Given a number which is power of 2, check if it is even power or odd power

I am given a number n , which is always a power of 2. I want to check whether n is odd power of 2 or even power of 2. For example: n=4 , ans= even n=8, ans=odd (because 8 is 2^3) n=1024 , ans=even. ...
5
votes
2answers
198 views

When should a trig function, with a degree argument, return -0.0?

In creating trig functions my_sind(d), my_cosd(d), my_tand(d), that used a degree argument rather than a radian one and provided exact answers at multiples of 90, I noticed that the result was ...
17
votes
7answers
2k views

What can one do to improve readability of math-oriented code in C#, Java, and similar? [closed]

As both a C programmer and a C# programmer, one of the things I don't like about C# is how verbose math functions are. Every time you would have to use a Sin, cosine, or power function for example, ...
4
votes
2answers
193 views

Decimal vs. Integer; Given a fixed range of values, which is preferable for accurate computation?

After getting into a "heated discussion" with someone, I figured I'd ask this question for the sake of posterity. I'm willing to be corrected if my assumption is incorrect but I'd like to hear a ...
1
vote
1answer
46 views

Create a collection with “average points” of N items from a pool with items of various points

Let's say I have a question pool to generate exams out of it. Each question contains a difficulty from 1 (hard) to 99 (easy). The questions are available in a hash / array (adapt to your favorite ...
1
vote
2answers
117 views

How can I make sense of the word “Functor” from a semantic standpoint? [closed]

When facing new programming jargon words, I first try to reason about them from an semantic and etymological standpoint when possible (that is, when they aren't obscure acronyms). For instance, you ...
10
votes
1answer
222 views

Implied precision of floating-point functions

While reviewing another programmer's implementation of a function to calculate the normal distribution CDF, I made a suggestion to either replace the entire implementation with Python's built-in ...
0
votes
1answer
44 views

Representing the hierarchy of groups of numbers using type inheritance

I've run into an interesting conundrum while coding my own implementations for the basic sets of mathematical numbers (Natural, Integer, Rational, Irrational, Real, Complex). I'm doing this mostly for ...
0
votes
1answer
144 views

Why are floats called “real numbers” in some languages?

Some programing languages, notably Pascal, have a type of numbers called "real". However, mathematically speaking, these types aren't real. For them to be "real", these types have to be able to ...
2
votes
2answers
323 views

Is Haskell appropriate for Signal Processing, Communication Systems and Information Theory? [closed]

I have been working on Software-Defined Radio projects for almost a year. This is an area which requires lots of signal processing (digital filters and FFTs), communication theory (modulation, ...
0
votes
1answer
132 views

Is hadoop designed only for “simple” data processing jobs, where communications between the distributed nodes are sparse?

I am not a professional coder, but rather an engineer/mathematician that uses computer to solve numerical problems. So far most of my problems are math-related, such as solving large scale linear ...
0
votes
0answers
40 views

Generating all the words accepted by a deterministic finite automaton [duplicate]

Imagine you've got a finite deterministic automaton A defining some finite regular language L, consisting of N words. The first question is: how would you determine the number of words N? Then, I ...
3
votes
1answer
400 views

Why did Shannon's outguessing machine beat Hagelbarger's?

I'm reading "Rock Breaks Scissors", which describes two "outguessing machines" built at Bell Labs that try to exploit human non-randomness in the game of matching pennies. There was an outguessing ...
0
votes
2answers
97 views

Fiscal quarter vs calendar quarter

I'm building a Date/Time class with a "configurable quarter" system as follows. User specifies which month the quarter starts at (config) Set of functions to deal with quarters (next quarter, prev ...
2
votes
0answers
41 views

Time passage arithmetic explanation

I ported this from http://www.effectgames.com/effect/article.psp.html/joe/Old_School_Color_Cycling_with_HTML5 some time ago. However i'm now wanting to modify it for the purpose of changing it from ...
1
vote
1answer
95 views

Is there an easy way to type in common math symbols?

Disclaimer: I'm sure someone is going to moan about easy-of-use, for the purpose of this question consider readability to be the only factor that matters So I found this site that converts to easting ...
0
votes
1answer
247 views

If a library doesn't provide all my needs, how should I proceed? [closed]

I'm developing an application involving math and physics models, and I'd like to use a Math library for things like Matrices. I'm using C#, and so I was looking for some libraries and found Math.NET. ...
4
votes
3answers
1k views

Japanese Multiplication simulation - is a program actually capable of improving calculation speed?

I'd like to write a simulation of Japanese Multiplication to get benchmarks on large calculations utilizing the shortcut vs traditional CPU multiplication. I'm curious as to whether it makes sense to ...
0
votes
3answers
116 views

Unique ID algorithm

I've got a route that contains objects. Each one has value 0 or 1. I need unique route ID which will identify any objects order. Currently I'm doing it using binary number that is converted to decimal ...
0
votes
2answers
230 views

Randomized Hash function with no collisions

Related to the question Which hashing algorithm is best for uniqueness and speed? Is there a way to create a hash function, or find one, whose hash length depends completely on the input length, has ...
0
votes
1answer
129 views

Why Num&sizeMinusOne faster than num&(size-1)

I've been told that when I have a hash table of size m and m=2^k, I can use the & operator as num & (size-1) instead of num % size, to fit the hashCode to my table size. I've also been told ...
5
votes
1answer
544 views

How to modify ELO algorithm when number of games is low to reduce outliers

I've developed the standard ELO implementation that can be found here, but the problem I'm running into is that my players will only have between 10 and 40 games in a "season". Since my first season ...
0
votes
1answer
187 views

Euclidean Space Fully Connected Nondirectional Graph: Shortest Path to all nodes

So this may be a question that is born of my inability to properly express my intentions to Google. In a fully connected non-directional graph such that any three points can be properly represented ...
2
votes
2answers
838 views

Representing a deck of cards in C (not C++)

So far my best ideas have been as fallows A) Represent a "card" in one structure and have a "deck" in another a deck being an array of 52 cards and a card being 2 chars one for and rank one for suit. ...
1
vote
2answers
147 views

Progress bar for unknown number of items

I am working on a survey-based feature in our application and the survey has branching points at any given question depending on the answer given. Each path that a branch can take may not have the ...
0
votes
1answer
109 views

Capture portions of a number using mathematical operations [closed]

Is there a mathematical way to get the following: For the the number 777,888,999 so 777 million and etc etc getMillions(777888999) should return 777 only getThousands(777888999) should return 888 ...
0
votes
1answer
339 views

Find possible variations of one item out of multiple baskets.

I have three baskets of balls and each of them has 10 balls which have the following numbers: Basket 1: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Basket 2: 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 ...
3
votes
1answer
638 views

What are the essential mathematics topics that a programmer should know in order to learn algorithms? [closed]

Being a electronics engineer, I was never exposed to any algorithms. Now I am a experienced programmer and want to learn Algorithms. I started with CLRS. But I was overwhelmed by the maths in the ...
22
votes
11answers
3k 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 ...
2
votes
1answer
187 views

Draw graph of a function whose characteristics are unknown [closed]

Suppose I have a function. I have code that, given an x value, produces a y value. I can assume that the function is somewhat mathematically sane, not something crazy like an ...
2
votes
2answers
253 views

How do you program a way to create mathematics formulas?

For one of my project ideas, I want to create a dice rolling app. It would allow people to setup somewhat complex combinations of dice roll cascades in a visual way. I have a pretty good idea on how ...
4
votes
2answers
941 views

How to represent a geometric line programmatically?

I have been trying to design a library to do some simple geometric computations in an Euclidean space regardless of its dimension. While it is easy to represent points, vectors, hyperspheres and ...