[PyFeyn] Bug in pyfeyn package

[Bridle I.H.]

Dear A. Buckley and G. von Hippel,

      After installing PyX 0.12.1 and Pyfeyn 0.3.2 today I ran some of your example scripts and found an error in pyfeyn\deco.py on line 27. The pyx.deco._arrowhead function is missing an argument and should read
"pyx.deco._arrowhead(arrowtopath, self.pos*dp.path.arclen(), 1, self.size, 45, 1, constrictionlen)",
where I have underlined the boolean "constriction" that was missing (see pyx.deco._arrowhead help).

Thank you for your work,

Mr I. H. Bridle

SHEP,

University of Southampton,

Southampton,

SO17 1BJ