docs: function mean(x) {
  	let result = [];
  	
  	for(let c = 0; c<x[0].length; c++){
  		result.push(0);
  	}
  	
  	for (let r = 0; r < x.length; r++) {
  		for(let c = 0; c<x[r].length; c++){
  			result[c] += x[r][c];
  		}
  	}
  	
  	for(let c = 0; c<x[0].length; c++){
  		result[c] /= x.length;
  	}
  	
  	return result;
  }