Radar chart

The network diagram also radar chart, radar chart Kiviat chart or star chart is a graphical representation of values ​​of several equivalent categories in a spider web form. Particularly good in this chart is to visualize evaluations for pre-determined criteria two (or more ) series.

For each category there is a axis. For all axes have the same orientation applies; the better values ​​are uniform in the center or outside of the beams.

The axes are arranged in a circle evenly into 360 degrees. The values ​​of each series are connected with lines. Wherein several series of colors may be used. The enclosed area is often filled in with color.

It must exist at least three categories, since in two of all lines lie on each other and no connection would be visible. With more than 10 axes the chart is confusing. But even in less than 4 axes afflicting each other because of the large distance, the quantitative perception. Therefore, the optimal number 5-7 axes.

Even if individual criteria, a comparative statement is possible to multi-dimensional quantities can not compare. An exception are quantities that are better / worse in all criteria as a comparison set. They are then Pareto optimal. In the network diagram surround the comparison set completely.

For example, if in the diagram shown to improve the values ​​with increasing numbers, the blue line pareto optimal with respect to the red dot. The green curve is not Pareto- comparable.

The star chart was first used by Georg von Mayr in 1877.