Mathematics

Historic Development of Calculus with Code

16 May 2021 by Kenneth Haugland

Showing the major stepping stones of the development of calculus and its precursors

Complex Math Parser and Evaluator in VB.NET

15 Aug 2023 by Xavier Junqué i de Fortuny

Reduces/evaluates a real/complex math expression

Parser

Maths in IT #2: Venn diagrams

9 Nov 2015 by Sander Rossel

Using Venn diagrams to visualize sets.

Iterated Function Systems and self similar fractals

22 Jan 2017 by Miguel Diaz Kusztrich

A simple way to build a wide family of fractals

The astounding Pickover's biomorphs

27 Nov 2017 by Miguel Diaz Kusztrich

An infinite set of biological shape fractals in the complex plain

Sunspot Surface Calculation (Case Study on solving complex problems)

14 Mar 2016 by V.

Case study on how to solve a complex problem by dividing it into smaller problems.

Python Fourier Transform Helper Library

13 Apr 2022 by Steve Hageman

A Python Library to help make properly scaled Fourier Transforms including utility functions

NewtonPlus - A Fast Big Number Square Root Function

1 Jul 2023 by Ryan Scott White

A fast, possibly the fastest, square root function for Big Integers and Floats in C# and Java.

Algorithmic approaches to solving the Pascal's Triangle and the Newton's Binomial

18 Aug 2014 by José Cintra

Some suggestions of algorithms for solving the Pascal Triangle, addressing iterative, recursive and functional paradigms

Semi-Prime Ordered Sequences (Part 2)

31 May 2016 by William Hey

Semi-Prime Ordered Sequences (Part 2) is the follow-on to “Exploring Computational Number Theory (Part 1)” and describes a process for ordering the semi-prime base sequences.

What is the 20 th number of this series 3,18,57,132...........????

20 Apr 2010 by harold aptroot

Looks like this one:http://www.research.att.com/~njas/sequences/A061317[^]

Sound in games - Rooms

31 Jul 2012 by Kenneth Haugland

How to calculate a reverbration time in a room

Fast High Precision Gamma Calculator

22 Apr 2018 by Mohammad Kazem Akhgary

Algorithm of gamma function with high precision using taylor series

Pathfinding (not the usual)

28 Feb 2013 by AspDotNetDev

That is called a weighted graph (where each edge has a "cost"). The "cost" in your case would be the total time to travel from one node to the next (which can be calculated with the inputs you specified, speed and distance).You mentioned one possible solution already: Dijkstra's algorithm,...

Addition without addition in C#?

6 Feb 2014 by CPallini

Yes, of course int a = 5; int b = 10; int c = a - (-b);

C# Implementation of Basic Linear Algebra Concepts

12 Mar 2020 by Mohammad Elsheimy

My C# implementation of linear algebra concepts (matrix elimination, multiplication, inverses, determinants, etc.)

Unveiling the Counterintuitive Nature of the Monty Hall Problem - A Simulation-Based Investigation

13 Jun 2023 by Jack Devey

This post delves into the perplexing Monty Hall paradox, examining the probabilities associated with sticking or switching doors in the game scenario.

Why is my SQL incorrectly doing math?

12 Mar 2024 by OriginalGriff

If I try your values I get what I expect:SELECT (487-556)/556 Gives me 0 as it is integer arithmetic.SELECT (487.0-556.0)/556.0 Gives me -0.1241 because it's floating point arithmetic. Check your data sources and make sure the types are what you...

SQL

what wronge with using floor(+0.5) as round?

13 Apr 2012 by Espen Harlinn

You'll find a pretty good answer here:http://www.cplusplus.com/forum/articles/3638/[^]Best regardsEspen Harlinn

Pathfinding (not the usual)

28 Feb 2013 by velvet7

Hi,I have already seen a lot of methods to find the right path from point A to B. (Astar, dijkstra, etc.)Now what I am trying to solve is something else, and i don't know if anyone have ever done something like this before...I'll try to explain.Let's say I have point A, B, and...

How to speed up exponentation.

27 Jun 2013 by nv3

I assume you are dealing here with big (multi-word) integers, as the context is encryption. If that is so you can make use of the fact that mod (a**b) = mod (mod(a) ** b)And that might be significantly faster if you use the multiplying approach for computing the power. Note that mod(a) is...

Exploring Computational Number Theory (Part 3)

26 Mar 2018 by William Hey

Factoring classic integers

What is the error? I cannot run the program.

2 Feb 2022 by OriginalGriff

When your code won't compile, start by looking at the error message. Pasting the legible part code into an online C++ compiler and trying to compile it, gives the first errors as: main.cpp:56:9: error: no match for ‘operator

programming

From Stationarity to Randomness through Chaos

22 Nov 2016 by Miguel Diaz Kusztrich

Using R to explore complexity of time series generated by simple process

NumberParser

2 Dec 2017 by User 6679439

Library extending the .NET numeric support

What is the 20 th number of this series 3,18,57,132...........????

20 Apr 2010 by Dalek Dave

Start at the beginning. Genesis 3.18 - Thorns also and thistles shall it bring forth to thee; and thou shalt eat the herb of the field;57 - Leads to a variety of bean related things.132 - 12th Heteromecic number, so may prove useful.I think the 20th must be 142857, a cyclic...

Generating descending frequency sinewave patterns - Impossible?!

26 Aug 2011 by mbue

You cannot multiply the absolute time by the current frequency. You have to integrate the time for each time slice multiplied by the frequency factor.For example:double currAngle = 0;for(...){ uiSample = (SHORT)(32767.0 * sin(RAD(currAngle));//dTime += dFactor; dDescension +=...

Making BIG calculations with vb.net(75+ digits)

3 Nov 2011 by Sergey Alexandrovich Kryukov

You need to use the structure BigInteger, see http://msdn.microsoft.com/en-us/library/system.numerics.biginteger.aspx[^]. It provides unlimited number if digits.This unit (the whole name space System.Numerics) was introduced in .NET Framework v.4.0. What if you need to use earlier version of...

All About Test Part 1 - Choosing Your Tests

21 Jan 2013 by Simeon Sheye

Beyond basic unit tests, how do you choose your tests and when are you done?

exp(-x) - sinx = 0; _ MATLAB

11 Jan 2014 by Andreas Gieriet

I strongly suggest to first get a "feeling" for the graph.1) sin(x) is periodically in 2⋅π and has roots every n⋅π (∀ n ∈ Ν0)2) sin(x) ≈ x (x much smaller than π/2)3) e-x goes monotoinc to zero (∀ x ∈ R, x ≥ 0)4) e-x has sample...

MatLab

m. s. bartlett fitting straight line always three groups?

11 Jan 2014 by Andreas Gieriet

I'm not familiar with that method, but my understanding from reading some online documentation (e.g. http://en.wikipedia.org/wiki/Bartlett's_method[^], http://math.mit.edu/linearalgebra/ila0403.pdf[^], etc.) I come to the following conclusion:Bartlett's method basicalliy calculates a series...

Convex Hull 2D, 3D, anyD

1 Feb 2014 by CPallini

Quote:Are there also convex hulls for any dimension?From Convex Hull Wikipedia[^]a page:"Formally, the convex hull may be defined as the intersection of all convex sets containing X or as the set of all convex combinations of points in X. With the latter definition, convex hulls may be...

Generic Vector<T> Class Implementation With Use of Expression Trees

21 Jul 2014 by Alexandr Stefek

This article show another way to implement generic operators. Vector is in middle of attention.

generics

Solving the Chinese Remainder Theorem Using Totients

2 Sep 2014 by Cryptonite

This code gives a solution to the Chinese Remainder Theorem using totients instead of the Extended Euclidean algorithm.

Network Calculus

12 Dec 2015 by JinWenQiang

This tip is a brief introduction of Network Calculus. I used Matlab codes to show you the results and to explain how it works.

Design

MatLab

How can I write my own sinus function?

22 Jan 2021 by OriginalGriff

The Taylor series for sin(x) is simple: sin(x) = pow(x, 1) - pow(x, 3) / 3! + pow(x, 5) / 5! - ... But your implementation does two things: starts with -1 instead of 1, and makes it look a lot more complex than it needs to be. If you don't...

Acoustic Radiation Impedance

14 Jan 2024 by Kenneth Haugland

Radiation from rectangular, circle and elliptic - shaped openings

What is the 20 th number of this series 3,18,57,132...........????

20 Apr 2010 by Keith Barrow

I don't know if this helps, but if you take the number, subtract the position in the sequence, then raise to the power of 1 divided by three you get a straight line.

Triangle Problem

30 Sep 2010 by Sauro Viti

No, you can't: to do it you need at least one of the side. To demonstrate my assertion think about this: take a triangle and its angles, then scale the triangle by an arbitrary factor, the three angles has not changed.In brief: by knowing the angles you can identify a family of triangles,...

Concave and Convex Polygon

1 Dec 2010 by Sauro Viti

To identify such points is quite simple:consider the point Pn and the two segments adiacent to the point; they are S1 = Pn - Pn-1 and S2 = Pn+1 - Pnnow consider the scalar and vectorial product of the two segments:S1 * S2 = |S1| * |S2| * cos(alpha)S1 ^ S2 = |S1| * |S2| *...

Where is that article on probability and birthdays?

5 Jan 2011 by wizardzz

I don't know where the CP article is, but here's a great article. I think it was originally in a newsletter article regarding a meetup and memorial for one of the fathers of...

general

Comparing Simple Sounds - What is the Closest Frequency

4 Mar 2011 by Dylan Morley

I'd say have a look at Autotune.Nethttp://channel9.msdn.com/coding4fun/articles/AutotuneNET[^]As you'll see, pitch detection is obviously vital to an autotune program, so that will help you with what you're trying to do.

Rotation of Point in 3D Space

18 Mar 2011 by Manfred Rudolf Bihy

This little elaboration will help you along the way: http://www.euclideanspace.com/maths/geometry/affine/aroundPoint/index.htm[^].It shows how to combine the rotation matrices with a translation to achieve the rotation about a given point. The page you found gives you the rotation matrices for...

Get all points in a Line

11 Jul 2011 by Аslam Iqbal

Find the slope m=(x1-x2)/(y1-y1) and make a loop of x where y=mx+c (c=0). now get (x,y) for a range of x. I'm not sure about my equations. please check those are correct or not.Correct equations, given (x1, y1) (x2, y2):m = (y1 - y2) / (x1-x2);c = y1 - x1 * m; ...

Find Prime Numbers in C# Using the Sieve of Eratosthenes

12 Sep 2011 by Bill Anderson

Here's an alternative. This one uses the BitArray class in C# and does not use the % operator.static List SeiveWithoutMod(int candidate){ BitArray sieveContainer = new BitArray(candidate + 1, true); int marker = 2; //start int factor = 2; //start. sieveContainer[0]...

Find Prime Numbers in C# Using the Sieve of Eratosthenes

30 Sep 2011 by Bill Anderson

Hi,Thanks for the feedback for alternative #1 from above (and thank you, Jurgen Rohr for your suggestion! I replaced the "reset" line with:while (!sieveContainer.Get(++marker));factor = marker;Here is another algorithm that's slightly different. It's not as elegant an approach, but...

what wronge with using floor(+0.5) as round?

13 Apr 2012 by nv3

Espen has already contributed a good link regarding the rounding. Thanks Espen, that got my 5.The reason I post this solution is to make you aware that there is better algorithm for line drawing that you might not be aware of. It was invented by Jack E. Bresenham and is named after...

Number sequences which minimise the risk of getting a valid number through a miss-key when inputted

Is it possible to create an exponent operator in java?

12 Jun 2012 by Sergey Alexandrovich Kryukov

In VB, the '^' operator is not exponent, but a power operator, N ^ p means Np, and "exponent" means ex, in VB it would be e ^ x:http://msdn.microsoft.com/en-us/library/zh100ckf%28v=vs.100%29.aspx[^]."Exponent" is a unary function, and there is no a unary operator for it in any language....

6 Jul 2012 by OriginalGriff

I would change it slightly, by putting a check digit either at the start or end of the number:If you use a (sum-of-digits plus digit-position-number) modulo 10 then your are unlikely to get the same check digit by a simple mistake. This would also protect against transposed digits: 12435...

numbers

Example code for equation of circle curve in C based language

5 Aug 2013 by Maciej Los

If i understand you well, you need to create 2 dimension array of chars (filled with 0 - zero), then to replace some chars with other (1 - one) to imitate a circle... The size of array should be calculated based on r (radius).Have a look here:...

Example code for equation of circle curve in C based language

5 Aug 2013 by CPallini

try:class Program { const int N = 20; static void Main() { char [, ] circle = new char[2*N+1, 2*N+1]; double phi, dphi = 0.5 / N; phi = 0.0; for (int y = 0; y

m. s. bartlett fitting straight line always three groups?

30 Oct 2013 by Ron Beyer

A better place to ask a question like this is Wolfram Alpha[^], ao forum dedicated to math nerds like this one is dedicated to programming nerds gurus.

Algorithmic approaches for computing the Fibonacci Numbers

24 Aug 2014 by José Cintra

Some suggestions of algorithms for computing the Fibonacci numbers addressing iterative, recursive and functional paradigms

What do you mean by shaders? Learn how to create them with HTML5 and WebGL

1 May 2015 by David Catuhe

Today I am going to try to explain you how shaders in babylon.js work.

HTML

Javascript

Making a 2D Physics Engine: Shapes, Worlds and Integration

29 Jan 2018 by Arav Singhal

Representing shapes, worlds, and integrating forces and velocities in a 2D physics engine

physics

Numerical Sequences Generator

26 Oct 2018 by José Cintra

Generic algorithm to generate mathematical sequences

Fibonacci sequence problems

15 Apr 2019 by Patrice T

Quote: When I run it against this only one issue is resolved, if anybody can tell me what i am doing wrong it will be greatly appreciated. About anything is wrong. import java.util.ArrayList; public class ResitCode { public int Fib_No(int position) { // here you receive the position...

Java

Empirical Pseudopotential

21 Jul 2021 by aroman

This blog entry shares a project that computes the band structure of a crystal having the diamond/zincblende structure, for various elements.

Nuclear Magnetic Resonance and Fourier Transform

21 Jul 2021 by aroman

In this post we introduce the Fourier Transform and hint about some of its usages.

in the state of texas,10.1% of the population is 65 of age or older. given these results, how many people in a town of 40,000 people would you expect to be at least 65 years old?

25 Mar 2010 by Luc Pattyn

42 of course. All the others migrated to Florida.:)

what is the 20 th no. of this series 3,18,52,132.............

20 Apr 2010 by Dalek Dave

We don't do homework questions, and certainly not ASAP.However, take 3, double it and add 12 to give 1818, doubled add 16 (four more than 12) to give 52Double it, add 20 (four more than 16) to give 132Continue along that line to yield 10485668 as the 20th iteration.Assuming that...

What is the 20 th number of this series 3,18,57,132...........????

20 Apr 2010 by Luc Pattyn

namespace aLittleProblem { static class Program { [STAThread] static void Main() { Console.WriteLine("16020"); } }}:)

Bell Curve, Gaussian Function, or Normal Distribution

3 Aug 2010 by Tim-bot

Simple calculation to determin a value at a percentage along a bell curve. Also with an offcenter curve intersection thing....

Windows

Height and Distance

28 Sep 2010 by Sauro Viti

You have to solve the following equation system:R * cos(ß) = X2R * cos(ß + Ө) = X1Then:R * cos(ß) = X2R * (cos(ß) * cos(Ө) - sin(ß) * sin(Ө)) = X1Now, divide the 2nd equation by the first:cos(Ө) - tg(ß) * sin(Ө) = X1 / X2Then:tg(ß) = (cos(Ө) - X1 / X2) /...

Comparing Simple Sounds - What is the Closest Frequency

4 Mar 2011 by Albin Abel

Each piano key has unique frequency. So the frequency domain i.e fourier transformation helps to identify the pattern of the pure sound from noise. That pattern you could use compare the sound."Another thought I had was that a note should be more or less the same each time it is played. If...

MOD and DIV in C++ CLI

8 Oct 2011 by Simon Bang Terkildsen

% - mod/ - divint i1 = 5 % 2; // i1 == 1int i2 = 5 / 2; // i2 == 2

MFC

Making BIG calculations with vb.net(75+ digits)

3 Nov 2011 by WhiteKnightBRASIL

SOLVEDThx SAKryukov[^]Hey there! I need to make some BIG calculations using binomial coefficients[^]Ok, since vb.net doesn't have factorial nor binomial coefficient functions I've already done my own:Function fact(ByVal Number As Byte) As Decimal Dim i As Integer = 1 ...

what wronge with using floor(+0.5) as round?

13 Apr 2012 by User 59241

If you put this in the debugger which is the FIRST thing to do when debugging a program you will find floor() is working properly.The line yy[i+1]=floor(yy[i]+mm+0.5);does completely different things when you use floor() because yy[i+1] is dependent on yy[i].You...

from digital signals to data

2 May 2012 by Sergey Alexandrovich Kryukov

This is the very basic explanation:http://en.wikipedia.org/wiki/Analog-to-digital_converter[^].What happens from ADC to computer may vary. ADC can be a PCI card, it can be a part of stand-along device connected with one of the very many interfaces: Ethernet, serial port (such as RS-232),...

C# Round Up Values !!!

14 Jun 2012 by Roman Lerman

Hi,val = System.Math.Ceiling(val);Have a nice day

Need a code for soving a Mathematical Equation like this: 56*78+(78/8)?

17 Jul 2012 by Rahul Rajat Singh

I think this is what you are looking forExpression Evaluator for C# based on Expression Tree[^]Just do the following using sample code in the above article:IParser par = new ExpParser();ExpEvaluator eu = new ExpEvaluator(par); string expresion =...

calculator

Finding Recurring Cycle

22 Sep 2012 by Sandeep Mewara

Here, have a look at these:Project Euler 26: Find the value of d

Please clarify my doubt on matrix multiplication

9 Oct 2012 by Wes Aday

printf("%f",c[i][j]);You have not declared "c" in this statment anywhere. To use c in main you have to declare it just like you did for a and b.product(a,b);Does nothing because you are throwing the result away.

errors

Multiplying matrices in JavaScript

15 Nov 2012 by Sergey Alexandrovich Kryukov

I did not check up the code, but why not using 2-dimensional arrays which better fit the nature of a matrix and greatly simplify indexing? Just in case:http://www.kavoir.com/2009/02/javascript-multi-dimensional-array.html[^].—SA

Javascript

help needed: Prints numbers in a range.

26 Mar 2013 by Jochen Arndt

This can be done using a C program calling standard C library functions only. Then this source would be OS independant.To do this with Unix shells passing the range on the command line, read about shell programming (especially passing command line parameters, conditions, and arithmetric...

shell

how to calculate VAT percentage from VAT rupees in C#?

2 Apr 2013 by CPallini

Quote:Please Help me, Where I did wrong....Here:Quote:rupees = decimal.Divide(rupees, totalAmt);Should be:rupees = decimal.Divide(rupees, totalAmt-vatAmt);

WinForms

Weighted Generic Lottery in C#

26 Jun 2013 by Hossein Montazeri

A class to conduct a lottery, based on different chances of winning for every participant

Matrix Solving or Equation solving for 10^8 variables

3 Jul 2013 by SBK.V1.0

I am developing a simulation software which involves solving around 10^8 simultaneous linear equations. Equations are sparse. I already made a prototype in which I implemented LU decomposition myself. But my implementation can only address less than 10^4 equation due to performance and memory...

Converting Latitude And Longitude to an X Y Coordinates

27 Jul 2013 by Nelek

I had deleted the solution because I thought it was not "professional", but seeing your comments to other questions... I am getting it back from the Limbo. This is the text:Probably this is not going to be the best approach as well but... at least it could make it a bit easier. I am...

C++/CLI

Example code for equation of circle curve in C based language

5 Aug 2013 by nv3

What you probably mean is a parameterized circle equation: Let variable t run from 0 to 2*PI in small increments and then calculate: double x, y; x = cos (t) * r; y = sin (t) * r;This will give you a set of coordinated for a circle around the origin with radius r.If you...

Finding the Closest Latitude and Longitude in an OpenStreetMap CSV File

2 Dec 2013 by ExcelledProducts CEO

Closest latitude and longitude to a referenced latitude and longitude.

Java

Want to create intermidiate sound from two sound

28 Apr 2015 by Sergey Alexandrovich Kryukov

You messed up everything. Let's see how equal temperament works.You are trying to create equal temperament based on having 2 intermediate micro-tones between tones of 12-tone European system. It it also pretty apparent that you use the equal temperament and A440 pitch standard as the base....

graph

MatLab

A math Library to calculate strings

10 Jun 2015 by Andy Lanng

Nope. You may find an API but I'd write one myself.Look at the below example of how to parse arithmetic strings using stacked operators There may be a API you can pull out of it:Math Parser .NET C#[^]

string

A math Library to calculate strings

11 Jun 2015 by Stefan_Lang

This has nothing to do with math. Consequently you don't need a math library, but an expression parser: https://www.google.ch/search?q=experession+parser&ie=utf-8&oe=utf-8&gws_rd=cr&ei=D4J5VZmaHoKQsAGDh6eYBw#q=expression+parser+C%2B%2B[^]The first hit on that search already looks promising....

string

Displaying Mathematical Content with MathJax and JQuery Mobile

17 Oct 2015 by José Cintra

Tips for creating mathematical cross-platform applications in JavaScript and display formulas and other content with MathJax and JQuery Mobile.

How to calculate longitude2 latitude2 using longitude1 latitude 1 and the angle bearing

10 Nov 2015 by Patrice T

A simple Google research on longitude + latitude + bearing + distance leads you to...

physics

Knapsack Bitwise

17 Oct 2016 by Kerneels Roos

For the first post in this series I’ll present a solution to the 1⁄0, or binary version of this famous problem I designed in 2015.

I couldn't make my code sum the divisors

20 Oct 2017 by OriginalGriff

Well... the debugger would show you the problem pretty quickly, but you should be able to see it yourself with a quick glance over the code. for (x = 1; x

Making a 2D Physics Engine: Mass, Inertia and Forces

12 Nov 2018 by Arav Singhal

Calculating the mass and inertia of a body and applying forces to it

physics

Can you please solve a C++ problem?

21 Mar 2018 by CPallini

Yes, direction is affected. You should compute the horizontal and vertical components of the particle speed in the frame where the hit wall is the horizontal axys, invert the vertical speed component and then transform back to original axys.

collisions

Theoretical power generation formula in java

3 Aug 2018 by OriginalGriff

I suggest that you two classmates get together: Nikhila Vemuri - Professional Profile[^] Member 13937492 - Professional Profile[^] Since you are both posting the same homework question ... And see if you can understand this together, because we do not do your homework: it is set for a reason....

Java

My cosh versus their cosh

1 Oct 2018 by Rick York

I tried your formula in my little test bed which uses VS17 and I got exactly the same results you did. I tried various values for the iteration count from 32 to 128 and all gave the same result. FWIW, above about 127 gives an NAN. I think you are running into the numerical limits of 64-bit...

My cosh versus their cosh

3 Oct 2018 by Daniel Pfeffer

Writing a good mathematical library is very difficult. The library must not only give accurate results, but must also preserve other attributes, such as monotonicity (i.e. if the mathematical function is monotonic, your approximation should also be monotonic), odd/even behaviour (i.e. f(x) ==...

C# math.max not returning results.

16 Nov 2018 by OriginalGriff

You don't show us what you do with the eventual value (in AL) but since it's just a variable unless you "add it to a column" it's not going to show. The first thing you need to do is break out the debugger and look closely at exactly what is happening when you run that code with your data: put...

Aide :formule de calcul

22 Feb 2019 by Richard MacCutchan

OK, that is mathematics not programming.