m-thesis-documentation/figures/radio_interferometry/src/rit_scheme.py

153 lines
4.5 KiB
Python
Executable file

#!/usr/bin/env python3
__doc__ = \
"""
Show geometry and time delay between radio antennas
and a source (true, and expected).
"""
import matplotlib.pyplot as plt
from matplotlib.path import Path
import matplotlib.patches as patches
import numpy as np
def antenna_path(loc, size=1, height=(.5)**(.5), width=1, stem_height=None):
stem_height = stem_height if stem_height is not None else height
vertices = [
(0, 0), # center, middle
( width/2*size, height/2*size), #right, top
( width/2*size, -height/2*size), #right, bottom
(-width/2*size, height/2*size), #left, top
(-width/2*size, -height/2*size), #left, bottom
(0, 0), # back to center
(0, -stem_height), # stem
(0, 0), # back to center
]
codes = [
Path.MOVETO,
Path.LINETO,
Path.LINETO,
Path.LINETO,
Path.LINETO,
Path.LINETO,
Path.LINETO,
Path.CLOSEPOLY,
]
# modify vertices
for i, v in enumerate(vertices):
vertices[i] = ( loc[0] + v[0], loc[1] + v[1] )
return Path(vertices, codes)
def radio_interferometry_figure(emit_loc=(3,8), resolve_loc=None, N_antenna=4, ant_size=0.5, **fig_kwargs):
fig, ax = plt.subplots(**fig_kwargs)
annot_kwargs = dict(
color='red',
fontsize=15,
)
ray_kwargs = dict(
marker=None,
ls='solid',
color='red',
alpha=0.8
)
antenna_patch_kwargs = dict(
edgecolor='k',
facecolor='none',
lw=2
)
antenna_patches = []
dx_antenna = 1.5
stem_height = ant_size
for i in range(N_antenna):
path = antenna_path( (4+dx_antenna*i, stem_height), size=ant_size, stem_height=stem_height)
patch = patches.PathPatch(path, **antenna_patch_kwargs)
ax.add_patch(patch)
antenna_patches.append(patch)
if i == N_antenna - 1:
ant_loc = path.vertices[0]
ax.annotate("$\\vec{a_i}$", (ant_loc[0]+0.4, 0.8), va='top', ha='left', **{**annot_kwargs, **dict(color='k')})
# ground level
ax.axhline(0, color='k')
# indicate antenna signal
ant_loc = antenna_patches[int(2/4*N_antenna)].get_path().vertices[0]
ax.annotate("$S_i(t)$", (ant_loc[0], ant_loc[1]-stem_height-0.2), va='top', ha='center', **annot_kwargs)
if emit_loc or resolve_loc:
# resolve_loc
if resolve_loc is None:
resolve_loc = emit_loc
if resolve_loc:
for i, antenna in enumerate(antenna_patches):
ant_loc = antenna.get_path().vertices[0]
# rays from the antenna to resolve_loc
ax.plot( (ant_loc[0], resolve_loc[0]), (ant_loc[1], resolve_loc[1]), **ray_kwargs)
if i == N_antenna - 1:
ax.annotate("$\Delta_i$", ( (ant_loc[0]+resolve_loc[0])/2, (ant_loc[1]+resolve_loc[1])/2 ), va='bottom', ha='left', **annot_kwargs)
ax.plot(*resolve_loc, 'ro')
ax.annotate("$S(\\vec{x}, t)$", resolve_loc, ha='left', va='bottom', **annot_kwargs)
# emit loc
if emit_loc:
ax.plot(*emit_loc, 'ko')
ax.annotate('$S_0$', emit_loc, ha='right', va='top', **{**annot_kwargs, **dict(color='k')})
ax.set_xlim(-1, 10)
ax.set_ylim(-1, 10)
ax.axis('off')
fig.tight_layout()
return fig
if __name__ == "__main__":
emit_loc = (2.5, 8)
figsize = (6,6)
from argparse import ArgumentParser
import os.path as path
parser = ArgumentParser(description=__doc__)
parser.add_argument('scenario', choices=['base', 'true', 'closeby', 'far-away'], default='true')
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")
###
emit_loc = None
resolve_loc = None
if args.scenario != 'base':
emit_loc = (2.5, 8)
if args.scenario == 'closeby':
resolve_loc = (3, 8)
elif args.scenario == 'far-away':
resolve_loc = (8, 8)
fig = radio_interferometry_figure(emit_loc=emit_loc, resolve_loc=resolve_loc, figsize=figsize)
if args.fname is not None:
plt.savefig(args.fname)
else:
plt.show()