Rather than giving complete details of all the available routines, this chapter just points out some of the ways that they can be used. See Appendix A for details of the calling sequences. Considerable variation in the appearance of the graph can be achieved using the following techniques.
Attributes Use different attributes to distinguish different datasets.
For example, one can suppress the tick marks, draw the tick marks projecting out of the box instead of into it, or draw a grid over the whole viewport. Note that in this example we have also specified tick intervals explicitly. This is often used, for example, in displaying digitized spectra. Error bars Graphs of real data often require the inclusion of error bars. The program then marks 15 data points, supplying the logarithms of frequency and flux density to PGPT .