This library provides KPlotWidget and KPlotObject classes.

KPlotWidget is a QWidget-derived class that provides a virtual baseclass 
for easy data-plotting. The idea behind KPlotWidget is that you only have 
to specify information in "data units"; i.e., the natural units of the 
data being plotted.  KPlotWidget automatically converts everything 
to screen pixel units.

KPlotWidget draws X and Y axes with tickmarks and tick labels.  It 
automatically determines how many tickmarks to use and where they should 
be, based on the data limits specified for the plot.  You change the limits 
by calling setLimits( double x1, double x2, double y1, double y2 ), and 
then calling updateTickmarks() to recompute the positions of tickmarks 
and ticklabels.

Data to be plotted are stored using the KPlotObject class.  KPlotObject
consists of a QPtrList of DPoints, each specifying the X,Y coordinates
of a data point (DPoint is like QPoint, but the X and Y values are doubles 
instead of ints).  KPlotObject also specifies the "type" of data to be 
plotted (POINTS or CURVE or POLYGON or LABEL).

Jason Harris
kstars@30doradus.org