Math 5610 - Computational Linear Algebra


Project maintained by BrandonFurman Hosted on GitHub Pages — Theme by mattgraham

Software Manual

Routine Name: absErrVecOneNorm

Author: Brandon Furman

Language: C++

Description/Purpose: This method returns the absolute error in the approximation of one vector by another when the 1-norm is used.

Input: The function accepts two vectors, in the form of array1D objects, as inputs. Both inputs are passed by reference.

Output: This function returns a double-precision number that represents the absolute error in the approximation of the first input by the second input.

Usage/Example:

array1D vec1, vec2;

vec1 = emptyVec(3);
vec1(0) = 5; vec1(1) = 4; vec1(2) = 3;

vec2 = emptyVec(3);
vec2(0) = 7; vec2(1) = 8; vec2(2) = 9;

double oneNorm = absErrVecOneNorm(vec1, vec2);

std::cout << oneNorm;

outputs the following to console:

12

Implementation/Code:

double absErrVecOneNorm(array1D vec1, array1D vec2) {

	int n1 = vec1.getLength();
	int n2 = vec2.getLength();

	if (n1 != n2) {
		throw std::invalid_argument("absErrVecOneNorm: Incompatible Vector Sizes");
	}

	double sum = 0.0;

	for (int i = 0; i < n1; i++) {

		sum += abs(vec1(i) - vec2(i));

	}

	return sum;
}

Last Modified: February/2019