# R - logb() Function

The R logb() function returns the natural logarithm (base e) or logarithm to the specified base of a given number. In special cases it returns the following:

• If the argument is NaN or less than zero, then the result is NaN.
• If the argument is positive infinity, then the result is positive infinity.
• If the argument is zero, then the result is negative infinity.

### Syntax

```logb(x, base)
```

### Parameters

 `x` `Required. `Specify column to compute on. `base` `Optional. ` Specify the base. Default is e.

### Return Value

Returns the natural logarithm or logarithm to the specified base of a given number.

### Example:

In the example below, logb() function is used to calculate the natural logarithm of a given number.

```#operating on single element atomic vector
print(logb(0))
print(logb(1))
print(logb(3))

cat("\nOperating on vector\n")
#operating on vector
v <- c(5, 10, 50)
print(logb(v))

cat("\nOperating on matrix\n")
#operating on matrix
m <- matrix(c(1, 10, 50, 100, 500, NaN), nrow=2)
print(logb(m))

cat("\nOperating on first column of matrix\n")
#operating on first column of matrix
print(logb(m[,1]))
```

The output of the above code will be:

``` -Inf
 0
 1.098612

Operating on vector
 1.609438 2.302585 3.912023

Operating on matrix
[,1]     [,2]     [,3]
[1,] 0.000000 3.912023 6.214608
[2,] 2.302585 4.605170      NaN

Operating on first column of matrix
 0.000000 2.302585
```

### Example:

Consider one more example where different base is used to compute the logarithms.

```#operating on single element atomic vector
print(logb(10, 2))
print(logb(10, 5))
print(logb(10, 10))

cat("\nOperating on vector\n")
#operating on vector
v <- c(10, 50, 100)
#using base-10
print(logb(v, 10))
#using base as vector
print(logb(v, c(10, 50, 100)))
```

The output of the above code will be:

``` 3.321928
 1.430677
 1

Operating on vector
 1.00000 1.69897 2.00000
 1 1 1
```

❮ R Math Functions

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