I'm trying to work with a line chart where I can "zoom in" on any data point by clicking on it.  One technique I'm attempting is to dynamically change the yAxisMinValue and the yAxisMaxValue so that I can view the data through a narrower range along the y-axis.  
  
  
  
For example, if my y-axis values are between 0 and 200 with a step of 10, I want to be able to view a slice of that chart by changing the yMin to 75 and the yMax to 125 thus also changing the interval on the y-axis from 20 to 5.  In doing so, I'm essentially saying that I don't want to see any data points that are above 125 or below 75.   
  
  
  
The problem is that whenever I set the yMin to a number greater than the smallest value, yMin is ignored and zero is used instead.  Also, if the yMax is set to a number less than the largest number, my yMax value is ignored. 
  
  
  
Is there a way that I can make my chart perform this way? 
  
  
  
Spoonware