- Trending Categories
Data Structure
Networking
RDBMS
Operating System
Java
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Rotation of a point about another point in C++
Rotation of a point X about origin is by an angle θ in anti-clockwise direction is done by −
X by θ about origin anti-clRotateockwise: X*polar( 1.0,θ ).
Here, the function polar for complex numbers is defined under <complex> header file and is used to find a complex number using phase angle and magnitude. polar(mag,angle) returns a complex number.
Rotation of point X about a point Y
To rotate a point about another point, we will use translation in which movement of all coordinates occur in a particular direction.
Steps to rotate X about Y.
Translate X to Y, so Y becomes the new origin. This can be done by subtracting Y from all points. X now becomes X-Y.
Rotate (X-Y) about new origin using above formula: (X-Y)*polar( 1.0,θ )
Back-translation by adding Y to all points.
Rotation of X about Y is : (X-Y)*polar( 1.0,θ ) + Y
Below is the code to demonstrate rotation of point about another point
Example
#include <iostream> #include <complex> using namespace std; typedef complex<double> point; #define x real() #define y imag() int main(){ // Rotate P about Q point X(5.0, 3.0); point Y(2.0, 4.0); // Angle of rotation is 90 degrees double theta = 3.14/2; point Xnew=(X-Y) * polar(1.0, theta) + Y; cout << "rotating X 90 degrees anti-clockwise about Y becomes:"; cout << "(" << Xnew.x << ", " << Xnew.y << ")" << endl; return 0; }
Output
rotating X 90 degrees anti-clockwise about Y becomes:(3.00239, 6.9992)
- Related Articles
- Finding reflection of a point relative to another point in JavaScript
- C++ Program to find out the moves to read a point from another point in a 2D plane
- How to detect point on canvas after canvas rotation in HTML5
- Find the Number of Ways to go From One Point to Another in a Grid using C++
- Floating point comparison in C++
- Best Meeting Point in C++
- How to create a point chart with point size increment based on the position of the point in R?
- Generate Random Point in a Circle in C++
- Find a partition point in array in C++
- Difference between Point-to-Point and Multi-point Communication
- Find intersection point of lines inside a section in C++
- C++ Floating Point Manipulation
- Point-to-Point Protocol (PPP)
- Define 'melting point' of a substance? What is the melting point of ice?
- Define 'boiling point' of a substance? What is the boiling point of water?
