Cartesian 3D Vector Lib

View on GitHub

A simple vector library written in plain C for educational purpose.

Introduction

This library is written in hope to simplify the coding process for non-professional vector computation.

This library should not be used for industrial or scientific use due to the limited precision and performance; Complex number is not supported either.

Usage

1. You may copy the files in ./include to your project directory and compile it seperately;

2. You may generate a single head file vector.h for your project:

   $ make single

   This generate a single head file in the project root directory ./. Copy the ./vector.h to your project and include it.

Example

This is a brief demonstration on the commonly used functions’ usage. The output of each statement follows in comments.

Several practical examples are available in ./example.

#include "include/vector.h"

int main(int argc, char const *argv[])
{
    // Initialize vectors

    vector A = vecSet(1.0, 2.0, 0.0); 
    vector B = vecSet(0.0, 1.0, 3.0);


    // vecPrint() pretty print the vector
    // in the form of <x,y,z> |modulus|
    
    printf("Vector A,B\n");
    vecPrint(A); // < 1.00, 2.00, 0.00> | 2.24| 
    vecnPrint(B, 4); // < 0.0000, 1.0000, 3.0000> | 3.1623|

    // Arithmetic operations
	// The comming statements demonstarte 
    // 1. Vector Addtion
    // 2. Vector Subtraction
    // 3. Vector Cross Product
    // 4. Vector Dot Product
    // 5. Vector Scalar Product
        
    printf("\nADD, SUB, CRX, DOT, SCL\n");
    vecPrint(vecAdd(A, B));  // < 1.00, 3.00, 3.00> | 4.36|
    vecPrint(vecSub(A, B));  // < 1.00, 1.00,-3.00> | 3.32|
    vecPrint(vecCrx(A, B));  // < 6.00,-3.00, 1.00> | 6.78|
    printf("% .2f\n",vecDot(A, B)); // 2.00
    vecPrint(vecScl(A, 4.0));  // < 8.00, 0.00, 0.00> | 8.00|
    
    // Find unit vector
    
    printf("\nUnit A,B\n");
    vecPrint(vecUnit(A));  // < 0.45, 0.89, 0.00> | 2.24|
    vecPrint(vecUnit(B));  // < 0.00, 0.32, 0.95> | 3.16|

    // Take negative

    printf("\nNEG A,B\n");
    vecPrint(vecNeg(A));  // <-1.00,-2.00,-0.00> | 2.24|
    vecPrint(vecNeg(B));  // <-0.00,-1.00,-3.00> | 3.16|

    // Take modulus
    
    printf("\nMOD A,B\n");
    printf("|% .2f|\n",vecMod(A));  // 2.24
    printf("|% .2f|\n",vecMod(B));  // 3.16

    return 0;
}

Type

vector

typedef struct Vector{
    double x;
    double y;
    double z;
    double mag;
}vector;

The vector type contains components in three dimensions and the overall magnitude. All these data are in double type. Each time an operation is performed to a vector, the magnitude would update automatically.

You may get a component directly:

vector V = vecSet(1.1, 2.2, 3.3);
printf("%f", V.x); // This prints out the x component of vector V

Functions

Arithmetic

Addition

vecAdd(A, B) returns the sum: A + B.

Subtraction

vecSub(A, B) returns the difference: A - B.

Negative

vecNeg(V) returns the negative: - V.

Modulus

vecMod(V) returns the modulus: | V |.

Unit Vector

vecUnit(V) returns the unit vector: ^ V.

Scalar Product

vecScl(V, s) returns the vector s * V.

Dot Product

vecDot(A, B) returns the dot product: A · B.

Cross Product

vecCrx(A, B) returns the Cross product: A × B.

Utilities

Initialization

There’re two ways to initialize a vector:

1. vecSet(x, y, z) returns a vector specify the coordinates (x,y,z).
2. vecInit() returns a vector with coordinates all of 0.0. However, you should use vecSet(0.0, 0.0, 0.0) instead for better readability.

Pretty Print

1. vecPrint(V) prints the vector in the form of <x, y, z> | modulus |, 2 decimal places by default
2. vecnPrint(V, p) using the specified precision p. If p is 0, print in exponential form.