# Built-in R Features - Math¶

We've talked a bit about some of the built-in math functions and features in R, but let's have one more look at a few of them:

- abs(): computes the absolute value.
- sum(): returns the sum of all the values present in the input.
- mean(): computes the arithmetic mean.
- round(): rounds values (additional arguments to nearest)

Here's a quick example of each:

In [7]:

    v <- c(-1,0,1,2,3,4,5)

In [8]:

    abs(-2)

Out[8]:
2
In [9]:

    abs(v)

Out[9]:

1. 1
2. 0
3. 1
4. 2
5. 3
6. 4
7. 5

In [10]:

    sum(v)

Out[10]:
14
In [11]:

    mean(v)

Out[11]:
2
In [13]:

    round(23.1231)

Out[13]:
23
In [14]:

    round(23.1231234,2)

Out[14]:
23.12

Want more built-in math functions? Check out:

## Numeric Functions

Function | Description
abs(x) | absolute value
sqrt(x) | square root
ceiling(x) | ceiling(3.475) is 4
floor(x) | floor(3.475) is 3
trunc(x) | trunc(5.99) is 5
round(x, digits=n) | round(3.475, digits=2) is 3.48
signif(x, digits=n) | signif(3.475, digits=2) is 3.5
cos(x), sin(x), tan(x) | also acos(x), cosh(x), acosh(x), etc.
log(x) | natural logarithm
log10(x) | common logarithm
exp(x) | e^x

You can also check out the documentation for even more functions, like those related to statistics (we'll cover those later on).