# MathFun

##### Miscellaneous Mathematical Functions

`abs(x)`

computes the absolute value of x, `sqrt(x)`

computes the
(principal) square root of x, $\sqrt{x}$.

The naming follows the standard for computer languages such as C or Fortran.

- Keywords
- math

##### Usage

```
abs(x)
sqrt(x)
```

##### Arguments

- x
- a numeric or
`complex`

vector or array.

##### Details

These are internal generic primitive functions: methods
can be defined for them individually or via the
`Math`

group generic. For complex
arguments (and the default method), `z`

, ```
abs(z) ==
Mod(z)
```

and `sqrt(z) == z^0.5`

.

`abs(x)`

returns an `integer`

vector when `x`

is
`integer`

or `logical`

.

##### S4 methods

Both are S4 generic and members of the
`Math`

group generic.

##### References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
*The New S Language*.
Wadsworth & Brooks/Cole.

##### See Also

`Arithmetic`

for simple, `log`

for logarithmic,
`sin`

for trigonometric, and `Special`

for
special mathematical functions.

‘plotmath’ for the use of `sqrt`

in plot annotation.

##### Examples

`library(base)`

```
require(stats) # for spline
require(graphics)
xx <- -9:9
plot(xx, sqrt(abs(xx)), col = "red")
lines(spline(xx, sqrt(abs(xx)), n=101), col = "pink")
```

*Documentation reproduced from package base, version 3.1.3, License: Part of R 3.1.3*