def test_savitzky_golay_fft():
y = np.random.normal(size=100)
for width in [3, 5]:
for order in range(width - 1):
f1 = savitzky_golay(y, width, order, use_fft=False)
f2 = savitzky_golay(y, width, order, use_fft=True)
assert_allclose(f1, f2)
def test_savitzky_golay_fft():
y = np.random.normal(size=100)
for width in [3, 5]:
for order in range(width - 1):
with pytest.warns(AstroMLDeprecationWarning):
f1 = savitzky_golay(y, width, order, use_fft=False)
f2 = savitzky_golay(y, width, order, use_fft=True)
assert_allclose(f1, f2)
h = np.exp(-0.5 * ((t - 20.) / 1.0)**2)
hN = h + np.random.normal(0, 0.5, size=h.shape)
Df = 1. / N / dt
f = fftpack.ifftshift(Df * (np.arange(N) - N / 2))
HN = fftpack.fft(hN)
#------------------------------------------------------------
# Set up the Wiener filter:
# fit a model to the PSD consisting of the sum of a
# gaussian and white noise
h_smooth, PSD, P_S, P_N, Phi = wiener_filter(t, hN, return_PSDs=True)
#------------------------------------------------------------
# Use the Savitzky-Golay filter to filter the values
h_sg = savitzky_golay(hN, window_size=201, order=4, use_fft=False)
#------------------------------------------------------------
# Plot the results
N = len(t)
Df = 1. / N / (t[1] - t[0])
f = fftpack.ifftshift(Df * (np.arange(N) - N / 2))
HN = fftpack.fft(hN)
fig = plt.figure(figsize=(5, 3.75))
fig.subplots_adjust(wspace=0.05,
hspace=0.25,
bottom=0.1,
top=0.95,
left=0.12,
right=0.95)
h = np.exp(-0.5 * ((t - 20.) / 1.0) ** 2)
hN = h + np.random.normal(0, 0.5, size=h.shape)
Df = 1. / N / dt
f = fftpack.ifftshift(Df * (np.arange(N) - N / 2))
HN = fftpack.fft(hN)
#------------------------------------------------------------
# Set up the Wiener filter:
# fit a model to the PSD consisting of the sum of a
# gaussian and white noise
h_smooth, PSD, P_S, P_N, Phi = wiener_filter(t, hN, return_PSDs=True)
#------------------------------------------------------------
# Use the Savitzky-Golay filter to filter the values
h_sg = savitzky_golay(hN, window_size=201, order=4, use_fft=False)
#------------------------------------------------------------
# Plot the results
N = len(t)
Df = 1. / N / (t[1] - t[0])
f = fftpack.ifftshift(Df * (np.arange(N) - N / 2))
HN = fftpack.fft(hN)
fig = plt.figure(figsize=(5, 3.75))
fig.subplots_adjust(wspace=0.05, hspace=0.25,
bottom=0.1, top=0.95,
left=0.12, right=0.95)
# First plot: noisy signal
ax = fig.add_subplot(221)
h = np.exp(-0.5 * ((t - 20.0) / 1.0) ** 2) hN = h + np.random.normal(0, 0.5, size=h.shape) Df = 1.0 / N / dt f = fftpack.ifftshift(Df * (np.arange(N) - N / 2)) HN = fftpack.fft(hN) # ------------------------------------------------------------ # Set up the Wiener filter: # fit a model to the PSD consisting of the sum of a # gaussian and white noise h_smooth, PSD, P_S, P_N, Phi = wiener_filter(t, hN, return_PSDs=True) # ------------------------------------------------------------ # Use the Savitzky-Golay filter to filter the values h_sg = savitzky_golay(hN, window_size=201, order=4) # ------------------------------------------------------------ # Plot the results N = len(t) Df = 1.0 / N / (t[1] - t[0]) f = fftpack.ifftshift(Df * (np.arange(N) - N / 2)) HN = fftpack.fft(hN) fig = plt.figure() fig.subplots_adjust(wspace=0.05, hspace=0.25, bottom=0.1, top=0.95, left=0.12, right=0.95) # First plot: noisy signal ax = fig.add_subplot(221) ax.plot(t, hN, "-", c="gray", lw=1) ax.plot(t, np.zeros_like(t), ":k", lw=0.5)
def test_savitzky_golay():
y = np.zeros(100)
y[::2] = 1
with pytest.warns(AstroMLDeprecationWarning):
f = savitzky_golay(y, window_size=3, order=1)
assert_allclose(f, (2 - y) / 3.)
h = np.exp(-0.5 * ((t - 20.) / 1.0) ** 2)
hN = h + np.random.normal(0, 0.5, size=h.shape)
Df = 1. / N / dt
f = fftpack.ifftshift(Df * (np.arange(N) - N / 2))
HN = fftpack.fft(hN)
#------------------------------------------------------------
# Set up the Wiener filter:
# fit a model to the PSD consisting of the sum of a
# gaussian and white noise
h_smooth, PSD, P_S, P_N, Phi = wiener_filter(t, hN, return_PSDs=True)
#------------------------------------------------------------
# Use the Savitzky-Golay filter to filter the values
h_sg = savitzky_golay(hN, window_size=201, order=4)
#------------------------------------------------------------
# Plot the results
N = len(t)
Df = 1. / N / (t[1] - t[0])
f = fftpack.ifftshift(Df * (np.arange(N) - N / 2))
HN = fftpack.fft(hN)
fig = plt.figure()
fig.subplots_adjust(wspace=0.05, hspace=0.25,
bottom=0.1, top=0.95,
left=0.12, right=0.95)
# First plot: noisy signal
ax = fig.add_subplot(221)
def test_savitzky_golay():
y = np.zeros(100)
y[::2] = 1
f = savitzky_golay(y, window_size=3, order=1)
assert_allclose(f, (2 - y) / 3.)
def compute_Weiner():
from scipy import optimize, fftpack
from astroML.filters import savitzky_golay, wiener_filter
#----------------------------------------------------------------------
# This function adjusts matplotlib settings for a uniform feel in the textbook.
# Note that with usetex=True, fonts are rendered with LaTeX. This may
# result in an error if LaTeX is not installed on your system. In that case,
# you can set usetex to False.
from astroML.plotting import setup_text_plots
setup_text_plots(fontsize=8, usetex=False)
#------------------------------------------------------------
# Create the noisy data
np.random.seed(5)
N = 2000
dt = 0.05
t = dt * np.arange(N)
h = np.exp(-0.5 * ((t - 20.) / 1.0) ** 2)
hN = h + np.random.normal(0, 0.5, size=h.shape)
Df = 1. / N / dt
f = fftpack.ifftshift(Df * (np.arange(N) - N / 2))
HN = fftpack.fft(hN)
#------------------------------------------------------------
# Set up the Wiener filter:
# fit a model to the PSD consisting of the sum of a
# gaussian and white noise
h_smooth, PSD, P_S, P_N, Phi = wiener_filter(t, hN, return_PSDs=True)
#------------------------------------------------------------
# Use the Savitzky-Golay filter to filter the values
h_sg = savitzky_golay(hN, window_size=201, order=4, use_fft=False)
#------------------------------------------------------------
# Plot the results
N = len(t)
Df = 1. / N / (t[1] - t[0])
f = fftpack.ifftshift(Df * (np.arange(N) - N / 2))
HN = fftpack.fft(hN)
fig = plt.figure(figsize=(5, 3.75))
fig.subplots_adjust(wspace=0.05, hspace=0.25,
bottom=0.1, top=0.95,
left=0.12, right=0.95)
# First plot: noisy signal
ax = fig.add_subplot(221)
ax.plot(t, hN, '-', c='gray')
ax.plot(t, np.zeros_like(t), ':k')
ax.text(0.98, 0.95, "Input Signal", ha='right', va='top',
transform=ax.transAxes, bbox=dict(fc='w', ec='none'))
ax.set_xlim(0, 90)
ax.set_ylim(-0.5, 1.5)
ax.xaxis.set_major_locator(plt.MultipleLocator(20))
ax.set_xlabel(r'$\lambda$')
ax.set_ylabel('flux')
# Second plot: filtered signal
ax = plt.subplot(222)
ax.plot(t, np.zeros_like(t), ':k', lw=1)
ax.plot(t, h_smooth, '-k', lw=1.5, label='Wiener')
ax.plot(t, h_sg, '-', c='gray', lw=1, label='Savitzky-Golay')
ax.text(0.98, 0.95, "Filtered Signal", ha='right', va='top',
transform=ax.transAxes)
ax.legend(loc='upper right', bbox_to_anchor=(0.98, 0.9), frameon=False)
ax.set_xlim(0, 90)
ax.set_ylim(-0.5, 1.5)
ax.yaxis.set_major_formatter(plt.NullFormatter())
ax.xaxis.set_major_locator(plt.MultipleLocator(20))
ax.set_xlabel(r'$\lambda$')
# Third plot: Input PSD
ax = fig.add_subplot(223)
ax.scatter(f[:N / 2], PSD[:N / 2], s=9, c='k', lw=0)
ax.plot(f[:N / 2], P_S[:N / 2], '-k')
ax.plot(f[:N / 2], P_N[:N / 2], '-k')
ax.text(0.98, 0.95, "Input PSD", ha='right', va='top',
transform=ax.transAxes)
ax.set_ylim(-100, 3500)
ax.set_xlim(0, 0.9)
ax.yaxis.set_major_locator(plt.MultipleLocator(1000))
ax.xaxis.set_major_locator(plt.MultipleLocator(0.2))
ax.set_xlabel('$f$')
ax.set_ylabel('$PSD(f)$')
# Fourth plot: Filtered PSD
ax = fig.add_subplot(224)
filtered_PSD = (Phi * abs(HN)) ** 2
ax.scatter(f[:N / 2], filtered_PSD[:N / 2], s=9, c='k', lw=0)
ax.text(0.98, 0.95, "Filtered PSD", ha='right', va='top',
transform=ax.transAxes)
ax.set_ylim(-100, 3500)
ax.set_xlim(0, 0.9)
ax.yaxis.set_major_locator(plt.MultipleLocator(1000))
ax.yaxis.set_major_formatter(plt.NullFormatter())
ax.xaxis.set_major_locator(plt.MultipleLocator(0.2))
ax.set_xlabel('$f$')
plt.show()
pfit = np.poly1d(np.polyfit(sortedPhase, fluxByPhase, deg=d, w=weights))
fitCurve = pfit(sortedPhase)
strCurve = fluxByPhase / fitCurve
else:
fluxByPhase = [f for _, f in sorted(zip(phase, astDiffFlux))]
errByPhase = [f for _, f in sorted(zip(phase, astFluxErr))]
sortedPhase = sorted(phase)
sortedPhaseBin = sorted(rtp.binning(phase, time, binW, ind)[0])
fluxByPhaseBin = rtp.binWeighted(fluxByPhase, time, astFluxErr, binW,
ind)[0]
weights = [1. / (err**2) for err in errByPhase]
pfit = np.poly1d(np.polyfit(sortedPhase, fluxByPhase, deg=d, w=weights))
fitCurve = pfit(sortedPhase)
strCurve = fluxByPhase / fitCurve
fluxByPhaseSG = savitzky_golay(fluxByPhase, window_size=wsSG, order=4)
#----- Fourier Fit ------------------------------------------------------------
omega = 2 * np.pi / Prot * 24.
mtf = MultiTermFit(omega, ffOrder)
mtf.fit(time, astDiffFlux, astFluxErr)
phaseFit, fluxFit, phasedTime = mtf.predict(1000, return_phased_times=True)
phaseFit -= phasedTime[0]
phasedTime -= phasedTime[0]
phasedTime = [1 + t if t < 0 else t for t in phasedTime]
phaseFit = [1 + t if t < 0 else t for t in phaseFit]
plt.errorbar(phasedTime,
astDiffFlux,
astFluxErr,
