In case you want to add descriptional information on the plot you can superimpose individually defined Points and Lines. For both points and lines you may add strings to be displayed. See Figure 3.3 for an example.
First you have to define the coordinate definition, that is in which coordinate system do you define the coordinates (x,y) for the points and lines.
Next you define the Points and Lines that should be displayed on the plot.
Figure 3.3 Example of grid plot with additional points and lines
