set terminal pdf mono
set output "fig-gamma-pyx.pdf"
set size 6
set tics in
set mtics 1
set xlabel "$x$"
set ylabel "$y$"
set key bottom right
set axis x2 atzero
set x2format ""
set axis y2 atzero
set y2format ""
pos(y)=(y>0)?y:1/0
neg(y)=(y<0)?y:1/0
plot [-5:5][-5:5]\
 "out.gamma.txt" using ($1):pos($2) with lines linetype 1 title "$\\Gamma(x)$"\
,"out.gamma.txt" using ($1):neg($2) with lines linetype 1 notitle\
,"tab.gamma.txt" with points pointtype 17 title "data"\