/usr/lib/pd/extra/mapping/circular.pd is in pd-mapping 0.2.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | #N canvas 1 53 599 452 10;
#X obj 62 10 inlet;
#X obj 195 405 outlet;
#X obj 65 172 expr 1 - sqrt(1 - pow($f1 \, 2));
#X connect 0 0 2 0;
#X connect 2 0 1 0;
|