- Thread starter
- #1

#### OhMyMarkov

##### Member

- Mar 5, 2012

- 83

I'm a bit confused about referring to a mapping as function or functional, for example: $f(x_1, x_2, x_3) = x_1+2x_2 ^2+3x_3 ^3$. $f$ takes vector $\textbf{x}=[x_1 \; x_2 \; x_3]$ and maps it to a scalar. Now, is $f$ a

**function**or a

**functional**?

Thanks!