Graphical procedures

The graphical facilities are an important and extremely versatile component of the S-PLUS environment. Best results are obtained when S-PLUS is used with a high quality graphics system such as Xwindows, although even a simple ASCII terminal can be quite effective for some purposes.

Before the graphical facilities of S-PLUS may be used, it is necessary to inform S what type of device is being used by starting a device driver. In an Xwindows environment, the command to do this may be

X11()

(which creates a separate window in which high-quality graphical output will appear,) or for a simpler graphics terminal the command

tek4014()

may be appropriate.

Once a device driver is running S-PLUS plotting commands can be used to construct and display graphical objects. Plotting commands are divided into three basic groups:

High-level

plotting functions create a new plot on the graphics device, possibly with axes, labels, titles and so on.

Low-level

plotting functions add more information to an existing plot, such as extra points, lines and labels.

Interactive

graphics functions allow you interactively add information to, or extract information from, an existing plot, using a pointing device such as a mouse.

• High-level plotting commands
  • The plot() function
  • Displaying multivariate data
  • Display graphics
  • Arguments to high-level plotting functions
• Low-level plotting commands
• Interactive graphics functions
• Using graphics parameters
  • Permanent changes: the par() function
  • Temporary changes: arguments to graphics functions
• Graphics parameters list
  • Graphical elements
  • Axes and Tick marks
  • Figure Margins
  • Multiple figure environment
• Device drivers
  • PostScript diagrams for typeset documents.
  • Multiple graphics devices