How to download and try this example

Usage: pl -gif quarters.htm

In order to use date quarters notation, the X range must be specified 
with scaletype date using a month-day-year notation such as mmddyy; 
then before plotting bars, switch to X scaletype date nqyy (or some other
quarters notation) using proc defineunits.

It must be done this way because internally dates in quarters notation 
are converted to a midpoint mmddyy, e.g. 1Q99 -> 2/15/99  and 
3Q99 -> 8/15/99.  This is done for plotting and date arithmetic purposes.

Kind of tricky I realize.. it is touched on in the pl dates man page.

// do areadef with X scaled in years, using proc areadef #proc areadef title: Average dividend yield,\nby quarter rectangle: 1 1 4 2.5 xscaletype: date mmddyy xrange: 010198 123101 yrange: 3.0 6.0 // do year X axis using proc xaxis #proc xaxis stubs: inc 1 year stubformat: yyyy ticlen: 0 0.2 location: min-0.18 axisline: none stubslide: 180(s) // do another X axis to show quarters, using proc xaxis #proc xaxis stubs: inc 3 month stubformat: Q tics: none stubdetails: adjust=0,+0.05 stubslide: 45(s) // do a Y axis using proc yaxis #proc yaxis stubs: inc 0.5 grid: color=blue stubformat: %3.1f%% // switch to nqyy notation... #call $changeunits( x, "date nqyy" ) // specify data using proc getdata #proc getdata data: 1Q98 5.3 2Q98 4.9 3Q98 4.7 4Q98 4.8 1Q99 5.1 2Q99 4.8 3Q99 5.2 4Q99 5.3 1Q00 5.5 2Q00 5.2 3Q00 4.9 4Q00 4.9 1Q01 4.8 2Q01 4.9 // render bars using proc bars #proc bars locfield: 1 lenfield: 2 barwidth: 0.1 color: yelloworange