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Nicer plotting, proper use of datetime

merge-requests/2/head
Cees Bassa 2022-06-18 18:01:38 +02:00
parent 116153c784
commit 489678e321
3 changed files with 33 additions and 49 deletions
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25
rfplot.py
View File

@ -3,6 +3,8 @@ import numpy as np
from strf.rfio import Spectrogram
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
if __name__ == "__main__":
# Settings
@ -17,8 +19,25 @@ if __name__ == "__main__":
# Create plot
vmin, vmax = np.percentile(s.z, (5, 99.95))
fig, ax = plt.subplots()
ax.imshow(s.z, origin="lower", aspect="auto", interpolation="None",
vmin=vmin, vmax=vmax)
# Time limits
tmin, tmax = mdates.date2num(s.t[0]), mdates.date2num(s.t[-1])
# Frequency limits
fcen = np.mean(s.freq)
fmin, fmax = (s.freq[0] - fcen) * 1e-6, (s.freq[-1] - fcen) * 1e-6
fig, ax = plt.subplots(figsize=(10, 6))
ax.imshow(s.z, origin="lower", aspect="auto", interpolation="None",
vmin=vmin, vmax=vmax,
extent=[tmin, tmax, fmin, fmax])
ax.xaxis_date()
date_format = mdates.DateFormatter("%F\n%H:%M:%S")
ax.xaxis.set_major_formatter(date_format)
fig.autofmt_xdate(rotation=0, ha="center")
ax.set_xlabel("Time (UTC)")
ax.set_ylabel(f"Frequency (MHz) - {fcen * 1e-6:g} MHz")
plt.show()

20
strf/rfio.py
View File

@ -2,10 +2,10 @@
import os
import re
from datetime import datetime
import numpy as np
from datetime import datetime, timedelta
class Spectrogram:
"""Spectrogram class"""
@ -13,32 +13,34 @@ class Spectrogram:
"""Define a spectrogram"""
# Read first file to get number of channels
fname = os.path.join(path, "{:s}_{:06d}.bin".format(prefix, ifile))
fname = os.path.join(path, f"{prefix}_{ifile:06d}.bin")
with open(fname, "rb") as fp:
header = parse_header(fp.read(256))
# Set frequencies
freq = np.linspace(-0.5*header["bw"], 0.5*header["bw"], header["nchan"], endpoint=False)+header["freq"]+0.5*header["bw"]/header["nchan"]
freq_cen, bw, nchan = header["freq"], header["bw"], header["nchan"]
freq_min, freq_max = -0.5 * bw, 0.5 * bw
freq = freq_cen + np.linspace(freq_min, freq_max, nchan, endpoint=False) + freq_max / nchan
# Loop over subints and files
zs = []
mjds = []
t = []
isub = 0;
while isub<nsub:
# File name of file
fname = os.path.join(path, "{:s}_{:06d}.bin".format(prefix, ifile))
fname = os.path.join(path, f"{prefix}_{ifile:06d}.bin")
with open(fname, "rb") as fp:
next_header = fp.read(256)
while next_header:
header = parse_header(next_header)
# mjds.append(Time(header["utc_start"], format="datetime", scale="utc").mjd+0.5*header["length"]/86400.0)
zs.append(np.fromfile(fp, dtype=np.float32, count=header["nchan"]))
t.append(header["utc_start"] + timedelta(seconds=0.5 * header["length"]))
zs.append(np.fromfile(fp, dtype=np.float32, count=nchan))
next_header = fp.read(256)
isub += 1
ifile += 1
self.z = np.transpose(np.vstack(zs))
self.mjd = np.array(mjds)
self.t = t
self.freq = freq
self.siteid = siteid
self.nchan = self.z.shape[0]

37
strf/rfio.py~
View File

@ -1,37 +0,0 @@
class Spectrogram:
"""Spectrogram class"""
def __init__(self, path, prefix, ifile, nsub, siteid):
"""Define a spectrogram"""
# Read first file to get number of channels
fname = os.path.join(path, "{:s}_{:06d}.bin".format(prefix, ifile))
with open(fname, "rb") as fp:
header = parse_header(fp.read(256))
# Set frequencies
freq = np.linspace(-0.5*header["bw"], 0.5*header["bw"], header["nchan"], endpoint=False)+header["freq"]+0.5*header["bw"]/header["nchan"]
# Loop over subints and files
zs = []
mjds = []
isub = 0;
while isub<nsub:
# File name of file
fname = os.path.join(path, "{:s}_{:06d}.bin".format(prefix, ifile))
with open(fname, "rb") as fp:
next_header = fp.read(256)
while next_header:
header = parse_header(next_header)
mjds.append(Time(header["utc_start"], format="datetime", scale="utc").mjd+0.5*header["length"]/86400.0)
zs.append(np.fromfile(fp, dtype=np.float32, count=header["nchan"]))
next_header = fp.read(256)
isub += 1
ifile += 1
self.z = np.transpose(np.vstack(zs))
self.mjd = np.array(mjds)
self.freq = freq
self.siteid = siteid
self.nchan = self.z.shape[0]
self.nsub = self.z.shape[1]