Write a function to evaluate f$($x$,$ y$)$ for any two user specified values x

and y$.$ The function f$($x$,$ y$)$ is defined as:

f$($x$,$ y$)=$

$$

$$

$$

x $+$ y x $>0$ and y $>0$

x $+$ y

$2$ x $>0$ and y $<0$

x

$2+$ y x $<0$ and y $>0$

x

$2+$ y

$2$ x $<0$ and y $<0$ in matlab coding