R - log1p() Function

The R log1p() function returns the natural logarithm of (1 + number), i.e., log(1+number). In special cases it returns the following:

• If the argument is NaN or less than -1, then the result is NaN.
• If the argument is positive infinity, then the result is positive infinity.
• If the argument is -1, then the result is negative infinity.

Syntax

log1p(x)

Parameters

Return Value

Returns the base-10 logarithm of the value.

Example:

In the example below, log1p() function is used to calculate the base-10 logarithm of a given number.

#operating on single element atomic vector
print(log1p(-1))
print(log1p(0.5))
print(log1p(1))

cat("\nOperating on vector\n")
#operating on vector
v <- c(0, 10, 50)
print(log1p(v))

cat("\nOperating on matrix\n")
#operating on matrix
m <- matrix(c(0, 10, 50, 100, 500, NaN), nrow=2)
print(log1p(m))

cat("\nOperating on first column of matrix\n")
#operating on first column of matrix
print(log1p(m[,1]))

The output of the above code will be:

[1] -Inf
[1] 0
[1] 1.098612

Operating on vector
[1] 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
[1] 0.000000 2.302585