m-thesis-documentation/figures/clocks/src/reference-clock.py

176 lines
4.4 KiB
Python
Executable file

#!/usr/bin/env python3
__doc__ = \
"""
Generate a figure showing the alignment of an external clock
referenced to a WR clock as could be seen on an oscilloscope.
"""
import matplotlib.pyplot as plt
import numpy as np
import scipy.signal as sig
### Functions
def plot_signal( ax, t, t_edge, s_edge, name=None, box_kw={'hatch': '/'}, line_kw={}, annotate_t_edge=True,**plot_kw):
"""
Plot a signal directly on an axis.
Uses t_edge to trigger height
"""
lower = (t > t_edge)
upper = (t > t_edge + s_edge)
# merge dictionaries correctly
line_kw = { **plot_kw, **line_kw }
# plot lower and upper lines
l = ax.plot(t, lower, **line_kw)
## update colour when plot_kw was empty
plot_kw = { **plot_kw, **{'color': l[0].get_color()} }
line_kw = { **plot_kw, **line_kw }
box_kw = { **plot_kw, **box_kw }
l2 = ax.plot(t, upper, **line_kw)
# plot the shaded box of width t_sigma
l3 = ax.fill_between(t, upper, lower, **box_kw)
# annotations
if name is not None:
if annotate_t_edge:
# annotate t_edge
y = 1
ax.annotate("$t_\mathrm{{{}}}$".format(name),
xy=(t_edge, y), xytext=(t_edge-3, y),
va='top', ha='center'
)
# annotate s_edge
y = 0.3
annotate_width(ax, "$\sigma_\mathrm{{{}}}$".format(name), t_edge, t_edge+s_edge, y)
return [l, l2, l3]
def plot_diff_time(ax, name, t_1, t_2, y, vline_kw={}, va='bottom'):
ax.axvline(t_1, **vline_kw)
ax.axvline(t_2, **vline_kw)
arrow_kw = {
'va':va,
}
annotate_width(ax, name, t_1, t_2, y)
def annotate_width(ax, name, x1, x2, y, text_kw={}, arrow_kw={}):
default_arrow_kw = dict(
xy = (x1, y),
xytext = (x2,y),
arrowprops = dict(
arrowstyle="<->",
shrinkA=False,
shrinkB=False
),
)
default_text_kw = dict(
va='bottom',
ha='center',
xy=((x1+x2)/2, y)
)
an1 = ax.annotate("", **{**default_arrow_kw, **arrow_kw})
an2 = ax.annotate(name, **{**default_text_kw, **text_kw})
return [an1, an2]
## Main
def main():
"""
Create a figure with two signals at times t1 and t2 (accuracy s1, s2)
as compared to a reference timer tr (sr), with annotations.
"""
t = np.linspace(0, 100, 1e3)
t_A = 40
t_B = 70
t_ref = 10
s_A = 10
s_B = 10
s_ref = 5
box_kw = {
"alpha": 0.3,
"hatch": '\\',
}
line_kw = {
}
vline_kw = {
"linestyle": '--',
"color": "k",
}
fig, axs = plt.subplots(3,1,sharex=True, gridspec_kw={'hspace': 0});
# Overall styling
axs[-1].set_xticks([])
axs[-1].set_xticklabels([])
for ax in axs:
ax.set_ylim(-0.2, 1.2)
ax.set_yticks([])
ax.set_yticklabels([])
ax.grid()
# Create the plots
i = -1
# Signal A
i+=1
y = 0.6
axs[i].set_ylabel("Signal A")
plot_diff_time(axs[i], "$t_\\mathrm{A}}$", t_ref, t_A, y, vline_kw=vline_kw)
plot_signal(axs[i], t, t_A, s_A, name="A", box_kw=box_kw, line_kw=line_kw, annotate_t_edge=False)
# Reference
i+=1
axs[i].set_ylabel("Reference")
axs[i].axvline(t_ref, **vline_kw)
plot_signal(axs[i], t, t_ref, s_ref, name="ref", box_kw=box_kw, line_kw=line_kw, color='g')
plot_diff_time(axs[i], "$t_\\mathrm{C}$", t_A, t_B, 0.3, vline_kw=vline_kw)
# Signal B
i+=1
axs[i].set_ylabel("Signal B")
plot_diff_time(axs[i], "$t_\\mathrm{B}}$", t_ref, t_B, y, vline_kw=vline_kw)
plot_signal(axs[i], t, t_B, s_B, name="B", box_kw=box_kw, line_kw=line_kw, color='purple', annotate_t_edge=False)
return fig, 0
if __name__ == "__main__":
from argparse import ArgumentParser
import os.path as path
parser = ArgumentParser(description=__doc__)
parser.add_argument("fname", metavar="path/to/figure[/]", nargs="?", help="Location for generated figure, will append __file__ if a directory. If not supplied, figure is shown.")
args = parser.parse_args()
if args.fname is not None and path.isdir(args.fname):
args.fname = path.join(args.fname, path.splitext(path.basename(__file__))[0] + ".pdf")
###
fig, _ = main()
if args.fname is not None:
plt.savefig(args.fname)
else:
plt.show()