.fromAngle[Rad|Deg]( angle ) ?

[DrLightman]

Maybe add a .fromAngleRad( angle ) such as:

Victor.fromAngleRad = function ( angle ) {
    return new Victor(Math.cos( angle ), Math.sin( angle ));
}

[rmkane]

@DrLightman wouldn't radians be the default:

Victor.fromAngle = function(radians) {
  return new Victor(Math.cos(radians), Math.sin(radians));
}

And then maybe:

Victor.fromAngleDeg = function(degrees) {
  return Victor.fromAngle(degrees * (Math.PI / 180));
}