Routine Name: vectorNormL1

Author: Christopher Johnson

Language: C++11. Tested with g++ compiler.

Declared in “vectorCode.h”

Description/Purpose: Calculates the l1 norm of input vector.

Input: Vector v, typedef of std::vector<double>;

Output: A double, indicating the l1 norm of the input value.

Usage/Example: The user must first define a vector, after which the method may be called on the vector.

Vector a = {1,2,3};
std::cout << "Let the vector A be given as\n";
printVector(a);
std::cout << "The l1 norm of A is " << vectorNormL1(a) << std::endl;

Output from the lines above:

The l1 norm of A is 6

Implementation/Code: The following is the code for vectorNormL1(v)

double vectorNormL1 (Vector v)
{
    double sum = 0.0;
    for (int i=0; i<v.size(); i++)
        sum+=std::abs(v[i]);
    return sum;
}

Last Modified: October/2017