sfpldb and splas are utilities for debugging Vplot files by converting them to the plain text (ASCII) form. pldb (plot debugger) converts a Vplot file to a text form, plas (plot assembler) converts the text form back to the Vplot format.

Suppose, for example, that your Vplot file has a typo in the label which spells Dept instead of Depth. Here is a Unix one-liner for fixing the label:

< file.vpl sfpldb | sed s/Dept/Depth/ | sfplas > fixed.vpl

Here the Unix line editor sed gets sandwiched between sfpldb and sfplas.

These programs were initinally developed by Vplot’s original author, Joe Dellinger.

10 previous programs of the month:

• sfisolr2
• sfsimilarity
• sfmutter
• sfintbin
• sfbox
• sfslant
• sfgrey
• sfhistogram
• sfmf
• sfbin