There are a number of tasks that display on a PGPLOT device. These devices include, of course, PostScript disk files that you can spool to a laser printer (see Chapter 3 for details of how to use PGPLOT). For image display, there is a suite of tasks called cginit , cgdisp , cgcurs , cgslice , and cgspec . We will discuss the first four in this chapter, and cgspec in Chapter 18.
Until recently, the labelling of coordinates in the ( cg) suite of software was restricted to a linear approximation that was correct in the centre of the region displayed. Despite this, coordinate exchange via input and output text (overlay) files, and by direct reporting to the user (cgcurs ) correctly dealt with non-linear coordinates; just the labelling on the plots was wrong. A code change (September 5 1995) has corrected the labelling deficiency so that non-linear axes are now appropriately labelled. This can be seen in wide fields by the sloping ticks which can be extended into a full coordinate grid.