When one or more datasets are empty within a plot, the Range.combine method returns incorrect results. The range for an empty dataset will have lower and upper values of NaN, signifying that the range is undetermined. When combining with a range that *is* determined, the NaN values prevail, which is incorrect. NaN values should be explicitly detected and discarded. Currently, determination relies on the Math.min and max methods. When run as so:
... the result is always NaN.