In r programming, an atomic vector is the most fundamental type of data structure. In an atomic vector, all the components have the same basic data type. Each data type is called an atomic mode and they can be logical, numeric, character, complex, and raw data modes. Sometimes in processing data, it is necessary to convert other data structures into a r vector.

### Description – the as.vector function

When you need to convert a data type into an r vector so that you can apply vector functions to it, use the as.vector function. This function comes in the format of as.vector(data structure) where “data structure” is the data you are converting to an r vector. Using as.vector in r produces a vector of the length of the number of data points being converted. This formula will not convert a data frame or a character string. Instead, it will output the same data structure.

### Explanation of the as.vector Function

When using the as.vector function, the resulting atomic vector will be either a logical vector, character vector, numeric vector, complex vector, or raw data vector. A numeric can be either an integer vector or a real vector. This function treats missing values as part of the data set of the same type as the other values. The as.vector function will not convert a data frame. It will not give you an error message, but the output is a data frame and not an r vector. This is probably because data frames can have mixed data types. This formula will, however, convert the individual columns of a data frame into an atomic vector. This means it is still useful when dealing with data frames.

### Examples of the as.vector function

Here we have two examples of this function being used.

> a = array(c(1, 2, 3, 4, 5, 6), c(3, 2))

> a

[,1] [,2]

[1,] 1 4

[2,] 2 5

[3,] 3 6

> v = as.vector(a)

> v

[1] 1 2 3 4 5 6

In this first example, the element being entered into our formula is a three-by-two array. The formula converts it into a single line atomic vector of numeric values.

> m = matrix(c(1:9), 3, 3)

> m

[,1] [,2] [,3]

[1,] 1 4 7

[2,] 2 5 8

[3,] 3 6 9

> c = as.vector(m)

> c

[1] 1 2 3 4 5 6 7 8 9

In this second example, the element being entered into our formula is a three-by-three matrix. The formula converts it into a single line atomic vector of numeric values.

### Application of the as.vector Function

This function’s most common application comes in cases where you are loading data into your program from an external source. When this is the case, you often do not have control over the way the data is formatted. In fact, the data structures being used may not even be consistent. This function allows you to convert most other data structures into an atomic vector allowing you to use vector functions on them. In such cases, you can be converting an unknown data structure into one that you can make use of.

When dealing with data, you do not always have control over how it is formatted. As a result, you may have to change the original format into one of your choosing. Vectors are the most basic data format in r programming and they are the easiest to work with. This makes vectors the perfect choice when you must convert from one data structure to another. The as.vector function is a tool that allows you to get data in the format that you need.