I've 2 arrays ($numbers and $letters) and I want to create a new array based on a function that combines every $numbers with every $letters. The parameters of this function involes the value of both $numbers and $letters. (Note: $numbers and $letters doesn't have the same amount of values). I need something like this:

$numbers = array(1,2,3,4,5,6,...);
$letters = array('a','b','c','d','e',...);

function myFunction($x,$y){
     // $output = some code that use $x and $y
     return $output;
};

$array_1 = array( (myFunction($numbers[0],$letters[0])), (myFunction($numbers[0],$letters[1])), myFunction($numbers[0],$letters[2]), myFunction($numbers[0],$letters[3]), etc);

$array_2 = array( (myFunction($numbers[1],$letters[0])), (myFunction($numbers[1],$letters[1])), myFunction($numbers[1],$letters[2]), myFunction($numbers[1],$letters[3]), etc);

$array_3 = array( (myFunction($numbers[2],$letters[0])), (myFunction($numbers[2],$letters[1])), myFunction($numbers[2],$letters[2]), myFunction($numbers[2],$letters[3]), etc);

...

$array_N = array( (myFunction($numbers[N],$letters[0])), (myFunction($numbers[N],$letters[1])), myFunction($numbers[N],$letters[2]), myFunction($numbers[N],$letters[3]), etc);

$array = array($array_1, $array_2, $array_3, etc.);

I know that this may work, but it's a lot of code, especially if I have a many values for each array. Is there a way to get the same result with less code? I tried this, but it's not working:

$array = array_map("myFunction($value, $letters)",$numbers));

Any help would be appriciated!