How to reduce array's numeric values, skipping strings - arrays

Question

Using Google Sheets' Script Editor, I need to calculate the average of each column of a table such as this one:
+---------+---------+---------+---------+
| | User 1 | User 2 | User 3 |
+---------+---------+---------+---------+
| | 20/1/17 | 21/1/17 | 22/1/17 |
+---------+---------+---------+---------+
| Movie 1 | 6 | 2 | 0 |
+---------+---------+---------+---------+
| Movie 2 | 2 | 1 | 5 |
+---------+---------+---------+---------+
| Movie 3 | 3 | 1 | 2 |
+---------+---------+---------+---------+
I want the result to be:
+---------+---------+---------+
| User 1 | User 2 | User 3 |
+---------+---------+---------+
| 3.6 | 1.3 | 2.3 |
+---------+---------+---------+
I have this code, which works if I use it on a table composed by numbers only. The problem is my table has strings in it, so the .reduce returns a #NUM! error (Result was not a number).
var sum = array.reduce(function(r, e, i) {
e.forEach(function(a, j) {
r[j] = (r[j] || 0) + a
})
if (i == array.length - 1) r = r.map(function(el) {
return el / array.length
});
return r;
}, []);
return sum;
How can I perform the average with the numeric values only? I tried using .filter, but it didn't seem to work on Google Apps Script Editor, or maybe I was just using it wrong (very likely).
This is the condition I was using to filter:
(typeof el !== 'number')

Answer 1

How about following sample? You can use this on Google Apps Script.
var array = [
[,, 'User 1', 'User 2', 'User 3'],
['Movie 1', '20/1/17', 6.0, 2.0, 5.0],
['Movie 2', '21/1/17', 2.0, 0.0, 2.0],
['Movie 3', '22/1/17', 3.0, 1.0, 3.0]
];
var sum = array.reduce(function(r, e, i) {
e.forEach(function(a, j) {
r[j] = (parseInt(r[j]) || 0) + a;
})
if (i == array.length - 1) r = r.map(function(el) {
return isFinite(el) ? el : "";
});
return r;
}, []);
return [array[0].splice(2, 3), [x for each (x in sum)].splice(2, 3)];
>>> [[User 1, User 2, User 3], [11.0, 3.0, 10.0]]