Update to v1.0:

Through rewrite, almost from scratch, with a new emphasis on positive x.

figs/current.fig/current30.gnuplot

@@ -6,7 +6,8 @@ set xlabel "$\\frac{t\\omega}{2\\pi}$"
 set xtics 0,1
 set ytics -0.8,0.4
 
-set yrange [-0.85:0.85]
+set xrange [0:3]
+set yrange [-0.85:1.0]
 set y2range [-1.4:1.4]
 
 # default output canvas size: 12.5cm x 8.75cm
@@ -15,6 +16,8 @@ set term lua tikz size 8,6 standalone
 # no key
 set key off
 
+set label "\\bf (c)" at 2.65,0.9
+
 # set linestyle
 set style line 1 linetype rgbcolor "#4169E1" linewidth 3
 set style line 2 linetype rgbcolor "#DC143C" linewidth 3