def plot_cpu(*, reports, filename):
"""Read reports and plot the CPU"""
fig = plt.figure()
ax = fig.add_axes((0.1, 0.2, 0.8, 0.7))
ax.set_ylabel("% of CPU utilized")
ax.set_xlabel("Seconds from start of run")
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')
ax.set_ylim(ymin=0, ymax=400)
ymax = 100
lines = []
legends = []
for report in reports:
r = BulkReport(report)
xyvals = r.cpu_track()
# Extract timestamps and convert to seconds from beginning of run
xvals = [xy[0] for xy in xyvals]
xmin = min(xvals)
xvals = [(x - xmin).total_seconds() for x in xvals]
# Extract CPU% and find max val
yvals = [xy[1] for xy in xyvals]
ymax = max([ymax] + yvals)
# Plot and retain handle
line, = plt.plot(xvals, yvals, label='report')
lines.append(line)
ax.legend(handles=lines) # draw legends
ax.set_ylim(ymin=0, ymax=math.ceil(ymax / 100) * 100) # set ymax
plt.savefig(filename, format='pdf')
