In this tutorial, we will look at how to compute the logarithm of a value using log functions in R with the help of some examples.

## How to compute the log of a value in R?

You can use the built-in `log()`

function to compute the log of a value in R. Pass the value for which you want to compute the log as an argument. The following is the syntax –

# log function in R log(x, base)

The `log()`

function takes the following arguments –

`x`

– The value for which you want to compute the log.`base`

(optional) – The logarithmic base to use.

By default, the `log()`

function computes the natural log of a value if you don’t specify the base. If you specify the base, it computes the log with respect to the given base.

Note that R also has direct functions to compute the logarithm with common bases such as `log10()`

to compute log with 10 as the base and `log2()`

to compute log with 2 as the base.

## Examples

Let’s look at some examples of using the above functions in R.

### Natural log in R

To get the natural log of a value in R, pass the value to the `log()`

function without any additional arguments. For example, let’s compute the natural log of some numbers using this method –

# natural log of value print(log(1)) print(log(2))

Output:

[1] 0 [1] 0.6931472

We get the natural log of 1 as 0 and 2 as 0.693.

### Log with base 10 in R

Let’s now compute the log with base 10 for a value. For this, you can either directly use the `log10()`

function or use the `log()`

function with `base=10`

.

Let’s look at an example.

# log with base 10 print(log10(100)) print(log(100, 10))

Output:

[1] 2 [1] 2

Here, we compute the log with base 10 of the number 100 using the functions `log10()`

and `log()`

(with the base as 10). You can see that we get the same result from both methods.

### Log with base 2 in R

You can similarly compute the log with base 2 for a value in R. That is, either directly use the `log2()`

function or use the `log()`

function with `base=2`

.

Let’s look at an example.

# log with base 2 print(log2(8)) print(log(8, 2))

Output:

[1] 3 [1] 3

Here, we compute the log with base 2 of the number 8 using the functions `log2()`

and `log()`

(with the base as 2). You can see that we get the same result from both methods.

### Log with custom base for a value in R

As shown above, you can use the `log()`

function with a custom base value. For example, let’s compute the log of 9 with base 3.

# log with custom base print(log(9, 3))

Output:

[1] 2

We get 2 as the output.

In this tutorial, we looked at how to compute the logarithm of a value in R using the function `log()`

which computes the natural log by default but can be customized to compute the log with respect to a different base using the `base`

parameter. We also looked at some specific log functions such as `log10()`

and `log2()`

which compute the log with respect to base 10 and 2 respectively.

You might also be interested in –

- Common Trigonometric Functions in R
- Get the Square Root in R using sqrt()
- Get the Absolute Value in R using abs()

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