MATLAB - Magnitude of a Vector

Magnitude of a vector v with elements v1, v2, v3, …, vn, is given by the equation −

|v| = √(v1² + v2² + v3² + … + vn²)

You need to take the following steps to calculate the magnitude of a vector −

• Take the product of the vector with itself, using array multiplication (.*). This produces a vector sv, whose elements are squares of the elements of vector v.

  sv = v.*v;

• Use the sum function to get the sum of squares of elements of vector v. This is also called the dot product of vector v.

  dp= sum(sv);

• Use the sqrt function to get the square root of the sum which is also the magnitude of the vector v.

  mag = sqrt(s);

Example

Create a script file with the following code −

v = [1: 2: 20];
sv = v.* v;       %the vector with elements 
                  % as square of v's elements
dp = sum(sv);     % sum of squares -- the dot product
mag = sqrt(dp);   % magnitude
disp('Magnitude:'); 
disp(mag);

When you run the file, it displays the following result −

Magnitude:
36.469