R does not come with a standard error function. You need to either create a standard error function or use a package like plotrix to calculate.

**Standard Error in R**

The **standard error **in** R** is just the **standard deviation** divided by the **square root **of the sample size. The** variance** of the sampling distribution is the variance of the data divided by N, and the SE is the square root of that.

The formula for finding standard error in R is the following.

`se <- function(x) sqrt(var(x) / length(x))`

The standard error can be calculated by dividing the standard deviation of our input by the square root of the length of our input. Let’s take an example.

```
std <- function(a) sd(a) / sqrt(length(a))
op <- std(c(11, 21, 19, 46))
print(op)
```

**Output**

`[1] 7.564996`

And we get the Standard Error of the vector.

If you want to remove **NA** values, then you can use the following function.

```
std <- function(x, na.rm = FALSE) {
if (na.rm) x <- na.omit(x)
sqrt(var(x) / length(x))
}
op <- std(c(11, 21, 19, 46))
print(op)
```

**Output**

`[1] 7.564996`

Let’s take another example in which we will use the set.seed() function and then use the rnorm() function to generate 10 random numbers.

```
set.seed(1)
data <- rnorm(10)
print(data)
se <- sd(data) / sqrt(10)
cat("The Standard Error is: ", se)
```

**Output**

```
[1] -0.6264538 0.1836433 -0.8356286 1.5952808 0.3295078 -0.8204684
[7] 0.4874291 0.7383247 0.5757814 -0.3053884
The Standard Error is: 0.246843
```

**std.error Function in plotrix**

To use the std.error() function in R, install the **plotrix **package. The **plotrix** add-on package includes the **std.error()** function, which can also calculate the standard error of the mean.

The std.error() function calculates the standard error of the mean. The ** std.error() function ** will accept a numeric vector.

**Syntax**

`std.error(x,na.rm)`

**Arguments**

**x:**It is a vector of numerical observations.

**na.rm:**It is a dummy argument to match other functions.

**Example**

```
library("plotrix")
op <- std.error(c(11, 21, 19, 46))
print(op)
```

**Output**

`[1] 7.564996`

That is it for Standard Error in R tutorial.