The fundamental to calculate log in R is by using the log() method in the format of **log(value, base)** that returns the logarithm of the value in the base.

**Log in R**

The log() is a built-in R function that calculates logarithms. It calculates natural logarithms by default. The **log10()** function calculates common (i.e., base 10) logarithms. The **log2()** function computes binary (i.e., base 2) logarithms.

The general form **log(x, base)** calculates logarithms with base.

The** log1p(x)** function calculates accurately also for |x| << 1.

The **exp()** function calculates the exponential function.

The **expm1(x)** function calculates accurately for |x| << 1.

**Syntax of log()**

**log(x, base)**

**Parameters**

**x**– It is numeric to which log has to be computed**base**– It is the base of the log.

**Example**

Let’s find the natural log of 11 using the log() function.

```
data <- log(11)
cat("The natural logarithm of 11 is: ")
cat(data)
```

**Output**

`The natural logarithm of 11 is: 2.397895`

**Plotting the log()**

The most used plotting function in R programming is the **plot()** function. It is a generic function that has many methods called according to the type of object passed to the **plot()**.

Open the rstudio and write the following code.

```
data <- seq(0, 100, by = 0.1)
plot(data, log(data), typ = "l", col = "red")
```

**Output**

**Find the log of the vector sequence.**

To find the log of vector sequence, pass the vector to the log() function. Before that, you have to create a vector sequence if it is not available to you. Let’s create a vector sequence for our example.

```
vc <- (rep(1:5))
cat("The vector sequence is: ")
cat(vc, "\n")
```

It will give us the following sequence.

`The vector sequence is: 1 2 3 4 5`

To find the log, pass the sequence to a log() function.

```
vc <- (rep(1:5))
cat("The vector sequence is: ")
cat(vc, "\n")
cat("Find the log() of vector sequence is: ")
cat(log(vc))
```

**Output**

```
The vector sequence is: 1 2 3 4 5
Find the log() of vector sequence is: 0 0.6931472 1.098612 1.386294 1.609438
```

**Specify the log base in R**

You can specify the base of the log bypassing the second parameter to the log() function.

Let’s find the logarithmic value of the number or vector to the base 3.

```
data <- log(11, 3)
cat("The log() function in R with base 3: ")
cat(data)
```

**Output**

`The log() function in R with base 3: 2.182658`

Let’s find the log of vector sequence to the base 3.

```
vc <- (rep(1:5))
cat("The vector sequence is: ")
cat(vc, "\n")
cat("Find the log(vc, 3) of vector sequence is: ")
cat(log(vc, 3))
```

**Output**

```
The vector sequence is: 1 2 3 4 5
Find the log(vc, 3) of vector sequence is: 0 0.6309298 1 1.26186 1.464974
```

**log2() function in R**

To calculate the log value with the base 2, use the log2() function.

```
data <- log2(11)
cat("The log2() value of 11 is: ")
cat(data)
```

**Output**

`The log2() value of 11 is: 3.459432`

Let’s find the log of vector sequence to the base 2.

```
vc <- (rep(1:5))
cat("The vector sequence is: ")
cat(vc, "\n")
cat("Find the log2() of vector sequence is: ")
cat(log2(vc))
```

**Output**

```
The vector sequence is: 1 2 3 4 5
Find the log2() of vector sequence is: 0 1 1.584963 2 2.321928
```

**log10() function in R**

To calculate the log value with the base 10, use the log10() function.

```
data <- log10(11)
cat("The log10() value of 11 is: ")
cat(data)
```

**Output**

`The log10() value of 11 is: 1.041393`

Let’s find the log of vector sequence to the base 10.

```
vc <- (rep(1:5))
cat("The vector sequence is: ")
cat(vc, "\n")
cat("Find the log10() of vector sequence is: ")
cat(log10(vc))
```

**Output**

```
The vector sequence is: 1 2 3 4 5
Find the log10() of vector sequence is: 0 0.30103 0.4771213 0.60206 0.69897
```

**Find the log of the column in DataFrame**

You can calculate the log of the data frame column in R using the log() function. Let’s create a data frame and calculate the log of one of the data frame’s columns.

```
gaming <- data.frame(console_name = c("Playstation", "XBOX S"),
console_price = c(399, 299),
game_name = c("Spiderman", "Forza Motors"))
print(gaming)
```

**Output**

** console_name** **console_price** **game_name**
**1** Playstation 399 Spiderman
**2** XBOX S 299 Forza Motors

Let’s find the log values of the **console_price** column.

```
gaming <- data.frame(console_name = c("Playstation", "XBOX S"),
console_price = c(399, 299),
game_name = c("Spiderman", "Forza Motors"))
print(gaming)
gaming$price_log <- log(gaming$console_price)
print(gaming)
```

**Output**

** console_name console_price game_name**
**1** Playstation 399 Spiderman
**2** XBOX S 299 Forza Motors
** console_name console_price game_name price_log**
**1** Playstation 399 Spiderman 5.988961
**2** XBOX S 299 Forza Motors 5.700444

In this output, you can see that we have appended one more column called **price_log, **whose values are the log of a **console_price** column. So this is how you can use the log() function in R DataFrame.

That is it for the R log() function example.