[R] Invert the sign of a number

[Duncan Murdoch]

On 29/10/2009 6:06 AM, Fran100681 wrote:
> Hello,
> 
> just a simple question
> 
> How can I do to invert the sign of a number? (for example: -4 to 4, 2 to -2
> and so on..)
> I was looking for a specific function in R but I didn't found it...
> thank you

You want the unary - operator.  For example,

-x

has opposite signs to x.

Even

--4

will work to give 4, but it will scare C programmers, so it's probably 
best to use parentheses:

-(-4)

Duncan Murdoch