-for [i=0:3] '$tmpB' index i using 1:4 with linespoint ls i+1 title column(1),
-for [i=0:3] '$tmpB' index i using 1:3 with linespoint ls i+1 notitle,
-for [i=0:3] '$tmpB' index i using 1:2 with linespoint ls i+1 notitle" \
+for [i=0:$nb] '$tmpB' index i using 1:4 with linespoint ls i+1 title column(1),
+for [i=0:$nb] '$tmpB' index i using 1:3 with linespoint ls i+1 notitle,
+for [i=0:$nb] '$tmpB' index i using 1:2 with linespoint ls i+1 notitle" \