Updated March 13, 2023

## Introduction to Matlab ones

Matlab one’s function is used to get a scalar or a vector with all ‘ones’ (1s) as its elements. Loops like ‘while’ & ‘for’ increase the size of our data structure incrementally every time a loop is executed. This process adversely affects the performance of the program. Resizing arrays repeatedly requires extra time seeking bigger contiguous memory blocks & then placing the arrays into these blocks. Functions like Matlab ones are used to improve code performance by pre-allocating the space required for the input array.

**Syntax of Function ‘ones’ in Matlab:**

`A = ones`

`A = ones (n)`

`A = ones (size 1, size 2, size 3, ….)`

**Description:**

- A = ones will return scalar 1 as output.
- A = ones (n) will return a square matrix of order n X n.
- A = ones (size 1, size 2, size 3, ….) will return a matrix of required dimensions.

### Examples of Matlab ones

Given below are the examples of Matlab ones:

#### Example #1

In the first example, we will use ‘one’s function’ to create a square matrix of order 3 with all 1s as its elements.

Below are the steps that we will follow for this example:

- First, pass the required order as an argument to the one’s function.
- Display the output.

**Code:**

A = ones(3)

[Using ‘ones function’ with ‘3’ as the argument. Please note that we have passed ‘3’ as an argument because we need the matrix with 1s to be of order 3 x 3 ]A

[Displaying the output]This is how our input and output will look like in the Matlab command window:

**Input:**

`A = ones(3)`

A

**Output:**

As we can see in the output, the function ‘ones’ has given us a matrix of order 3 and with 1s as its elements.

#### Example #2

In this example, we will use one function to create a square matrix of order 4 with all 1s as its elements.

Below are the steps that we will follow for this example:

- First, pass the required order as an argument to the one’s function.
- Display the output.

**Code:**

A = ones(4)

[Using ones function with ‘4’ as the argument. Please note that we have passed ‘4’ as an argument because we need the matrix with 1s to be of order 4 x 4 ]A

[Displaying the output]This is how our input and output will look like in the MATLAB command window.

**Input:**

`A = ones(4)`

A

**Output:**

As we can see in the output, the function ‘ones’ has given us a matrix of order 4 and with 1s as its elements.

In the above 2 examples, we have used ‘ones function’ to create a square matrix of all ones. Next, we will see the syntax to create the matrix of the required order. i.e. a matrix which is not a square matrix.

#### Example #3

In this example, we will use ‘ones function’ to create a matrix with all 1s as its elements and order 2 x 3 ( 2 rows and 3 columns).

Below are the steps that we will follow for this example:

- First, pass the required order as an argument to the ones function.
- Display the output.

**Code:**

A = ones(2, 3)

[Using ones function with ‘2’ and ‘3’ as the arguments. Please note that we have passed 2, 3 as the arguments because we need the matrix with 1s to be of order 2 x 3 ]A

[Displaying the output]This is how our input and output will look like in the MATLAB command window.

**Input:**

`A = ones(2, 3)`

A

**Output:**

As we can see in the output, the function ‘ones’ has given us a matrix of order 2 x 3 and with 1s as its elements.

#### Example #4

In this example, we will use ‘ones function’ to create a matrix with all 1s as its elements and order 3 x 4 ( 3 rows and 4 columns).

Below are the steps that we will follow for this example:

- First, pass the required order as an argument to the ones function.
- Display the output.

**Code:**

A = ones(3, 4)

[Using ‘ones function’ with ‘3’ and ‘4’ as the arguments. Please note that we have passed 3, 4 as the arguments because we need the matrix with 1s to be of order 3 x 4 ]A

[Displaying the output]This is how our input and output will look like in the MATLAB command window:

**Input:**

`A = ones(3,4)`

A

**Output:**

As we can see in the output, the function ‘ones’ has given us a matrix of order 3 x 4 and with 1s as its elements.

### Conclusion

Ones function is used to get a scalar or a vector with all ‘ones’ (1s) as its elements Matlab ones is used to improving code performance by pre-allocating the space required for the input array. We can use ones function in its different forms to get the order of the matrix as per our requirement.

### Recommended Articles

This is a guide to Matlab ones. Here we discuss the introduction to Matlab ones along with appropriate examples, respectively. You may also have a look at the following articles to learn more –