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This tutorial will discuss the use of function in Matlab sum()to find the sum of all the elements in an array.

Use the MATLAB sum()function to get the sum of array elements.

To get the sum of each element in an array, we can use the built-in function of Matlab sum(). If sum()the input to the function is a vector or an array containing numbers, then sum()the function will return an output which will be the sum of each element of the array or vector. For example, let's sum()find the sum of a vector using the function in Matlab. See the code below.

v = [1 2 6];
s = sum(v)

Output:

s =

     9

If the input to the sum function is a matrix, then the output of the sum function will be a row vector containing the sum of each column of the matrix. For example, if we have a three-column matrix, the output of the sum function will be a row containing three elements, and each element will be the sum of one column. For example, let's sum()find the sum of a matrix using the sum function in Matlab. See the code below.

v = [1 2 6; 8 6 5]
s = sum(v)

Output:

v =

     1     2     6
     8     6     5


s =

     9     8    11

As you can see, there are three columns in the matrix and the output vector also has three elements, corresponding to the sum of each column. If we do not want to sum each column, but want to sum each row; we can also define it as the second parameter in the sum function using the integer 2. For example, let's use sum()the function in Matlab to calculate the sum of the rows of a matrix. See the code below.

v = [1 2 6; 8 6 5]
s = sum(v,2)

Output:

v =

     1     2     6
     8     6     5


s =

     9
    19

As you can see, there are two rows in the matrix and the output vector also has two elements, corresponding to the sum of each row. We can also define the output data type as the second parameter in the sum function. For example, let us define the output data type as double. See the code below.

v = [1 2 6; 8 6 5]
s = sum(v,'double')

Output:

v =

     1     2     6
     8     6     5


s =

     9     8    11

We can also find the sum of all the elements of an array using loops in Matlab. For example, we can use a for loop, iterate through each element in an array, and add it to a variable. For example, let's start a variable at zero, and when the first element arrives, we add zero to it and save the result to the variable. When the second element comes, we add this to the current result, and we will keep doing this until we have iterated through all the elements of the array.