1d convolution javascript

1function convolve(array, weights) {
2  if (weights.length % 2 !== 1)
3    throw new Error('weights array must have an odd length');
4
5  var al = array.length;
6  var wl = weights.length;
7  var offset = ~~(wl / 2);
8  var output = new Array(al);
9
10  for (var i = 0; i < al; i++) {
11    var kmin = (i >= offset) ? 0 : offset - i;
12    var kmax = (i + offset < al) ? wl - 1 : al - 1 - i + offset;
13
14    output[i] = 0;
15    for (var k = kmin; k <= kmax; k++)
16      output[i] += array[i - offset + k] * weights[k];
17  }
18
19  return output;
20}