def plot_summary(s, colour, title, ax=None):
ax = ax if ax else plt.gca()
mjd0 = int(s.mjd.min())
mjd = s.mjd - mjd0
ax.plot(mjd, s.flux, ls='None', marker='.', color='k',
zorder=2)
lims = (ax.get_xlim(), ax.get_ylim())
ax.errorbar(mjd, s.flux, s.std, ls='None', color=colour, alpha=0.5,
zorder=1)
ax.set_xlim(*lims[0])
ax.set_ylim(*lims[1])
ax.set(title=title)
def noisecharacterise(i, flux_limits, datadict, c='b', model=True, ax=None):
'''Characterises the noise level of bright, non saturated stars from the
output of sysrem as a function of number of bins'''
ax = ax if ax is not None else plt.gca()
tmid = datadict['time']
cadence = np.median(np.diff(tmid)) * 24 * 60
flux = datadict['flux']
binlow = 0.2
binhigh = 4.0
binstep = 0.1
binrange = [int(np.ceil(10.0 ** (x)))
for x in np.arange(binlow, binhigh, binstep)]
binrange = np.sort(np.array(list(set(binrange))))
binrange = binrange[binrange < len(flux[0]) / 3]
minflux, maxflux = flux_limits[i]
zero = 21.18135675
mag_min = zero - 2.512 * np.log10(maxflux)
mag_max = zero - 2.512 * np.log10(minflux)
rms_lim = 1e9
avflux = np.median(flux, axis=1)
stdflux = np.std(flux, axis=1)
rms = stdflux
# Fractional rms in units of mmag
rms = abs(1.0857 * 1000.0 * stdflux / avflux)
sane_keys = ((rms > 0) &
(avflux > 0) &
(avflux < maxflux) &
(avflux > minflux))
flux_sane = flux[sane_keys].copy()
logger.info('Stats: av: %s, std: %s, rms: %s', avflux, stdflux, rms)
logger.debug('nstars: %s, mag_min: %s, mag_max: %s, npoints: %s',
len(flux_sane), mag_min, mag_max, len(flux_sane[0]))
logger.debug('median flux range: %s to %s',
min(np.median(flux_sane, axis=1)),
max(np.median(flux_sane, axis=1)))
median_list = [np.median(rms[sane_keys])]
N_bin_list = [1]
quartiles = [
[np.percentile(rms[sane_keys], 25), np.percentile(rms[sane_keys], 75)]]
rms_error = [
(np.std(rms[sane_keys])) / np.sqrt(len(rms[sane_keys]) * 1000)]
for N in binrange:
logger.debug('bin size: %s', N)
binned = binning(flux_sane, N)
avflux = np.median(binned, axis=1)
stdflux = np.std(binned, axis=1)
rms = stdflux
rms = abs(1.0857 * 1000.0 * stdflux / avflux)
sanity = ((avflux < maxflux) & (avflux > minflux))
rmssane = rms[sanity]
median_list += [np.median(rmssane)]
quartiles += [[np.percentile(rmssane, 25), np.percentile(rmssane, 75)]]
N_bin_list += [N]
rms_error += [(np.std(rms[sanity])) / np.sqrt(rms[sanity].size)]
# Get the limits of the median list
prior = [median_list[0], median_list[-1]]
# Convert to numpy arrays
N_bin_list = np.array(N_bin_list)
median_list = np.array(median_list)
rms_error = np.array(rms_error)
quartiles = np.array(quartiles)
low_quart = quartiles[:, 0]
high_quart = quartiles[:, 1]
m = 15
output = leastsq(
fitnoise, prior, args=(N_bin_list[:m], median_list[:m], rms_error[:m]))
final = output[0]
noise_curve = noisemodel(final, N_bin_list)
white_curve = noisemodel([final[0], 0], N_bin_list)
red_curve = noisemodel([0, final[1]], N_bin_list)
return NoiseResult(
cadence * N_bin_list,
median_list,
rms_error,
white_curve)
def plot_breaks(s, ax=None):
ax = ax if ax else plt.gca()
for b in s.breaks:
ax.axvline(b, ls='--', color='k',
zorder=-10)
def plot_summary(s, colour, label='', ax=None):
ax = ax if ax else plt.gca()
ax.plot(s.mags, s.frms, ls='None', marker='.', color=colour, label=label)