Drawing Feynman diagrams with feynarts

[Andrea M.]

I'm trying to draw Feynman diagrams with the feynarts.sty package for LaTex. The problem is that if I write the following code

\begin{feynartspicture}(150,150)(1,1)
\FADiagram{}
\FAProp(0.,10.)(6.,10.)(0.,){/Straight}{0}
\FALabel(3.,9.18)[t]{$1$}
\FAProp(20.,10.)(14.,10.)(0.,){/Straight}{0}
\FALabel(17.,10.82){$2$}
\FAProp(6.,10.)(14.,10.)(0.8,){/Straight}{0}
\FALabel(10.,5.98)[t]{$3$}
\FAProp(6.,10.)(14.,10.)(-0.8,){/Straight}{0}
\FALabel(10.,14.02){$4$}
\FAVert(6.,10.){0}
\FAVert(14.,10.){0}
\end{feynartspicture}

I get this

instead of this

how can I fix this?

 

[Orodruin]

How did you compile the file and what output did you look at?

 

[Andrea M.]

I found the solution. I need to compile following the latex -> dvips -> ps2pdf sequence. This can be made in TexShop putting the command

%!TEX TS-program = latex

in the first line of the tex file.