>> ... could you send me some pcl5 pseudo-code for drawing bar charts and pie charts, from one o two data series? ...
I don't have any such samples, sorry.
For bar charts, you could probably use PCL5 Rectangular Area Fills (perhaps using Shaded fills), in conjunction with colour palettes.
For pie charts, it would probably be easier to use the HP-GL/2 vector language subset of PCL5.