\
set term svg background "white"; \
set out "Qspline.svg" ;\
set key out ;\
set xlabel "x" ;\
set ylabel "x" ;\
set grid ;\
set title "Quadratic spline example" ;\
plot \
 "out.data" index 0 using 1:2 title "data" \
,"out.data" index 0 using 1:3 title "deriv" \
,"out.data" index 0 using 1:4 title "integ" \
,"out.data" index 1 using 1:2 with lines title "eval" \
,"out.data" index 1 using 1:3 with lines title "deriv" \
,"out.data" index 1 using 1:4 with lines title "integ" \