RE: [Groff] Venn Diagram in Pic?

[Nathaniel Harward]

There is an old post from 2007 about Venn diagrams in PIC I found on Google
while looking for existing Venn/PIC help; after not really finding anything
I could use I created a few PIC macros for them after some experimentation
since I needed to make some.  I thought I'd post them here, there is a
picture of some samples at:
http://nharward.blogspot.com/2008/09/venn-diagrams-in-pic.html

For PIC newbies like me make sure to include the following snippet in your
troff/groff/whatever source to use them:

-- snip --

.PS
define vennDiagram1 {
    box height $1 width $2
    $3 at last box.nw - (0.1, 0.0)
    "U" at last box.ne - (0.1, 0.1)
    circle radius last box.height/4 at last box.c
    $4 at last circle.nw + (-0.1, 0.1)
    move to last box.e
}
define vennDiagram2 {
    box height $1 width $2
    $3 at last box.nw - (0.1, 0.0)
    "U" at last box.ne - (0.1, 0.1)
    circle radius last box.height/4 at last box.c - (last box.height/8, 0)
    $4 at last circle.nw + (-0.1, 0.1)
    circle radius last box.height/4 at last box.c + (last box.height/8, 0)
    $5 at last circle.ne + (0.1, 0.1)
    move to last box.e
}
define vennDiagram3 {
    box height $1 width $2
    $3 at last box.nw - (0.1, 0.0)
    "U" at last box.ne - (0.1, 0.1)
    circle radius last box.height/4 at last box.c - (last box.height/7,
-last box.height/10)
    $4 at last circle.nw + (-0.1, 0.1)
    circle radius last box.height/4 at last box.c + (last box.height/7,
last box.height/10)
    $5 at last circle.ne + (0.1, 0.1)
    circle radius last box.height/4 at last box.c - (0, last box.height/7)
    $6 at last circle.sw - (0.1, 0.1)
    move to last box.e
}
.PE

-- snip --

From then on you can use them in your document source; the example below
prints three diagrams one below the other:

-- snip --
.PS
vennDiagram1(2, 3, "1.", "A")
move down from last box.s
vennDiagram2(2, 3, "2.", "A", "B")
move down from last box.s
vennDiagram3(2, 3, "3.", "X", "Y", "Z")
.PE
-- snip --

Hope that helps.... somebody out there.  Big thanks to "PIC — A Graphics
Language for Typesetting User Manual" by Brian Kernighan (1991) for the
help.

Nat Harward