var mapRange = function(from, to, s) {
  // mapRange expects ranges generated by _.range
  var a1 = from[0];
  var a2 = from[from.length - 1];
  var b1 = to[0];
  var b2 = to[to.length - 1];
  return b1 + (s - a1) * (b2 - b1) / (a2 - a1);
};

// The range function is exclusive
var fromRange = _.range(0, 11);
var toRange = _.range(-1, 1);

// .map constructs a new array
fromRange = fromRange.map(function(s) {
  return mapRange(fromRange, toRange, s);
});

console.log(fromRange);