Null points make valid points disappear on scatter plot visualization

I am building an application in which the user is able to filter data points from a scatter plot visualization. If a point is filtered, I just mark it as null inside the data series. However, when a point gets null, a valid point also disappears. Fiddle here: [http://jsfiddle.net/icarofonseca/w4mzw787/](http://jsfiddle.net/icarofonseca/w4mzw787/)

More points are omitted if the number of null samples increases. This kind of problem does not occur if the null points are in the end of the series, as shown by the setTimeout function in the Fiddle.

(Note: as I implemented some interactive onclick events, it is useful for me to keep the points’ order so I can easily track them back even if I am plotting a filtered series, because they still have the same d.index.)