MATLAB is one of the most powerful tools for data manipulation in the world of data analysis. It provides developers with plenty of functions to help analyze, process, and manipulate data. One of these functions is the ‘round’ function, which is particularly useful when dealing with floating-point numbers to obtain better results.

In this article, we will explore some of the essential concepts behind the MATLAB 'round' function and how to use it for data manipulation.

What is MATLAB 'round' Function?

The ‘round’ function in MATLAB is a built-in function that rounds off the elements of any given matrix or vector to the nearest nearest integer or another desired precision. This function accepts various input arguments and allows you to specify the number of decimal points to round off numbers to.

The syntax of the MATLAB round function is as follows:

y = round(x)

y = round(x,n)

y = round(x,' dec ’)

Here, x is the input data such as a scalar, matrix or vector, and y is the output data generated by the function. The 'n' and 'dec' arguments are optional, where 'n' represents the number of decimal places to round off the numbers, and 'dec' specifies the rounding method.

Let's look at some examples to understand the usage of 'round' function better

Example 1: Rounding off g scalar value using 'round' function

Suppose we have a floating-point number g = 23.742, and we want to round it off to the nearest integer using the 'round' function. We can use the following syntax in MATLAB:

g = 23.742

h = round(g)

After executing this, the output value of 'h' will be 24.

Example 2: Rounding off a matrix to a desired precision using the MATLAB round function

Now, let's consider a 2×2 matrix where we want to round off all the elements to two decimal places. We can use the following syntax:

A=[2.5677 8.3646;

4.1234 6.2380];

B=round(A, 2)

After executing this code, the output in MATLAB will be:

B =

2.57 8.36

4.12 6.24

Example 3: Rounding off floating-point numbers to nearest multiples using the MATLAB round function

Suppose we have a vector X with four elements and we want to round off all its elements to the nearest multiples of 5. We can create this vector using the following syntax:

X = [11.5 14.8 22.5 25.5]

To round off these values, we can use the following code:

Y = round(X/5)*5

After executing above code fragment, the output in MATLAB will be:

Y =

10 15 20 25

Types of Rounding Methods in MATLAB

The 'round' function in MATLAB allows you to select different rounding methods based on the need of the problem. Here are a few popular methods:

1. Round to the nearest integer

This method is the default option used when we do not specify any argument with 'round' function. It rounds off the input value to the nearest whole number. If the decimal part of the number is less than 0.5, it will reduce the value of the input number to the corresponding integer, and if it is greater than or equal to 0.5, it will round up to the nearest integer. For example,

round(5.36)= 5

round(5.67)= 6

2. Round towards zero

When we specify zero in the second argument of the 'round' function, it rounds off the values of the input matrix towards zero. For example,

round(5.36,0)= 5

round(-5.67,0)= -5

3. Round to N decimal places

When we specify the number of decimal places in the second argument of the 'round' function, it rounds off the values of the input matrix to the specified number of decimal places. For example,

round (2.456, 2)= 2.46

round (5.6789, 3)= 5.679

Conclusion

The 'round' function in MATLAB is an important tool for data manipulation that allows you to round off floating-point numbers to the nearest integer or other desired precision. It can be beneficial when analyzing and processing data for specific purposes. MATLAB also has other functions like ‘ceil, 'floor,’ and ‘fix’ to further customize the rounding methods. So, mastering the 'round' function is one of the essential things to do when mastering MATLAB for data manipulation.