Stiff diagram is a widely used graphical representation to display the major ion composition of a water sample in hydrogeology and geochemistry. Cations and anions are plotted on two sides of the vertical axis (in milliequivalents per liter). This polygonal shape is very useful for a rapid visual comparison between different water samples.
This example displays multiple stiff diagrams on a map background. The background is a section of a map that was imported into an Origin matrix and plotted as an image plot.
Four layers of stiff diagram are placed on the map at each sampling point.
An extra layer in lower-right corner was added to act as a stiff diagram legend for the graph.