Comments added

TimeLineCoordinateSystem.js

@@ -86,6 +86,19 @@ function newTimeLineCoordinateSystem() {
 
     function transformThisPoint(point) {
 
+        /*
+
+        This is the straigh fordward transformation this object provides. The input is a point on the data set that wants to be plotted in a timeline.
+        The x value of the point must be a datetime.valueOf() and is going to be transformed into an x value on the coordinate system of the timeline.
+        The y value should be a value in the dataset at that moment in time. Depending on how this coordinate system was initialized then are the
+        possible values y can have. For sure it must be in the range between the min and max y declared at initialization. The y value has a special
+        treatment since the browser canvas object used, has a zero y value at the top, while the timeline we use has a zero y value at the botton,
+        for that reason y is flipped.
+
+        Besides this, what we do is to multiply by the scale, which in turn is calculated at initialization time depending on the values provided.
+
+        */
+
         point = {
             x: (point.x - this.min.x) * this.scale.x,
             y: maxHeight - (point.y - this.min.y) * this.scale.y