### 4.1.2 float

Although most programs only use integers, they are unpractical when doing
trigonometric calculations, transformations or anything else where you
need decimals. For this purpose you use `float`. Floats are normally
32 bit floating point numbers, which means that they can represent very large
and very small numbers, but only with 9 accurate digits. To write a floating
point constant, you just put in the decimals or write it in the exponential
form:
3.14159265358979323846264338327950288419716939937510 // Pi

1.0e9 // A billion

1.0e-9 // A billionth

Of course you do not need this many decimals, but it doesn't hurt either.
Usually digits after the ninth digit are ignored, but on some architectures
`float` might have higher accuracy than that. In the exponential form,
`e` means "times 10 to the power of", so `1.0e9` is equal to
"1.0 times 10 to the power of 9".
All the arithmetic and comparison operators can be used on floats.
Also, these functions operates on floats:

- trigonometric functions
- The trigonometric functions are:
`sin`, `asin`,
`cos`, `acos`, `tan` and `atan`.
If you do not know what these functions do you probably don't
need them. Asin, acos and atan are of course short for
arc sine, arc cosine and arc tangent. On a calculator they
are often known as inverse sine, inverse cosine and
inverse tangent.
`float log(float `*x*)
- This function computes the natural logarithm of
*x*,
`float exp(float `*x*)
- This function computes
**e** raised to the power of *x*.
`float pow(float|int `*x*, float|int *y*)
- This function computes
*x* raised to the power of *y*.
`float sqrt(float `*x*)
- This computes the square root of
*x*.
`float floor(float `*x*)
- This function computes the largest integer value less than or equal to
*x*. Note that the value is returned as a `float`, not an `int`.
`float ceil(float `*x*),
- This function computes the smallest integer value greater than or equal to
*x* and returns it as a `float`.
`float round(float `*x*),
- This function computes the closest integer value to
*x*
and returns it as a `float`.