7KPlotWidget is a QWidget-derived class that provides a virtual base class
8for easy data-plotting. The idea behind KPlotWidget is that you only have
9to specify information in "data units"; i.e., the natural units of the
10data being plotted. KPlotWidget automatically converts everything
11to screen pixel units.
13KPlotWidget draws X and Y axes with tick marks and tick labels. It
14automatically determines how many tick marks to use and where they should
15be, based on the data limits specified for the plot. You change the limits
16by calling `setLimits(double x1, double x2, double y1, double y2)`.
18Data to be plotted are stored using the KPlotObject class. KPlotObject
19consists of a QList of QPointF's, each specifying the X,Y coordinates
20of a data point. KPlotObject also specifies the "type" of data to be
21plotted (POINTS or CURVE or POLYGON or LABEL).