Whenever you divide by zero, KaleidaGraph will return a very large value (3.4e38 or 1.79e308, depending on the column format). As far as KaleidaGraph is concerned, this is infinity because dividing by zero results in an undefined value. You can use a mask function so that these values are not used when creating a plot.
KaleidaGraph is a thoughtfully designed graphing and data analysis application for research scientists, as well as for those in business and engineering fields. It produces publication-quality graphs, and easily converts the most complex data into a functional display.