Explanation

R can do way more than simple arithmetic calculations. In R there are several built-in functions that can help you to do mathematical calculations. We will explain more precisely what a function is later on in this chapter, but for now you can think of a function as a (magical) machine that takes some input, does something special with it, and then gives you an output.

For example, consider the function sqrt(): you can insert a number in the parentheses of this function, like: sqrt(49). Now, the function computes the square root of the given number, and then gives you the output (in this case it will give the number 7). Take a look at the functions on the right-hand side and try them yourself!

Examples

# Square Root 
sqrt(49) 
# Output: 7

# Absolute Value 
abs(-10) 
# Output: 10 

# Trigonometric function  
cos(pi) # cosine of pi radians, i.e. 180 degrees 
# Output: -1 

# Rounding 
round(3.14159, 2) # round to 2 decimal places 
# Output: 3.14

# The base of the natural logarithm
exp(1)
# Output: 2.718282

# Natural logarithm ln, base e is the default in R
# log()
log(exp(1))
# Output: 1

# log(x, base=...) logarithm with selected base
log(10^2, base=10)
# Output: 2