def from_lightkurve(self, ind=0, ticid=None, method=None, cutout_size=9):
"""Download cutouts around target for each sector using Lightkurve
and create light curves.
Requires either `ind` or `ticid`.
Parameters
----------
ind : int
Index of target array to download files for
ticid : int
TIC ID of desired target
pld : boolean
Option to detrend raw light curve with PLD
cutout_size : int or tuple
Dimensions of TESScut cutout in pixels
Returns
-------
LightCurveCollection :
~lightkurve.LightCurveCollection containing raw and corrected light curves.
"""
if ticid == None:
i = ind
ticid = self.target_list.ID.values[i]
# search TESScut for the desired target, read its sectors
sectors = self._find_sectors(ticid)
if isinstance(ticid, str):
ticid = int(re.search(r'\d+', str(ticid)).group())
print(
f'Creating light curve for target {ticid} for sectors {sectors}.')
# download the TargetPixelFileCollection for TESScut observations
tpfc = sr.download_all(cutout_size=cutout_size)
rlc = self._photometry(tpfc[0]).normalize()
# track breakpoints between sectors
self.breakpoints = [rlc.time[-1]]
# iterate through TPFs and perform photometry on each of them
for t in tpfc[1:]:
single_rlc = self._photometry(t).normalize()
rlc = rlc.append(single_rlc)
self.breakpoints.append(single_rlc.time[-1])
rlc.label = 'Raw {ticid}'
# do the same but with de-trending (if you want)
if method is not None:
clc = self._photometry(tpfc[0], method=method).normalize()
for t in tpfc[1:]:
single_clc = self._photometry(t, method=method).normalize()
clc = clc.append(single_clc)
clc.label = 'PLD {ticid}'
rlc = rlc.remove_nans()
clc = clc.remove_nans()
return lk.LightCurveCollection([rlc, clc])
else:
rlc = rlc.remove_nans()
return lk.LightCurveCollection([rlc])
def combine_lcs_and_calculate_and_plot_trend(star, *input_lcs):
lcs = []
flat_lcs = []
trend_lcs = []
for lc in input_lcs:
flat, trend = lc.flatten(window_length=301, return_trend=True)
lcs.append(lc)
flat_lcs.append(flat)
trend_lcs.append(trend)
lc = lk.LightCurveCollection(
lcs).stitch() #corrector_func=my_custom_corrector_func)
flat = lk.LightCurveCollection(flat_lcs).stitch()
trend = lk.LightCurveCollection(trend_lcs).stitch()
ax = lc.errorbar(label=star) # plot() returns a matplotlib axes ...
trend.plot(ax=ax, color='red', lw=2, label='Trend')
# which we can pass to the next plot() to use the same axes
return (lc, flat, trend)
def lcs_in_tpf(self, tpf_number):
"""
Returns the light curves from a given TPF as a lightkurve.LightCurveCollection.
Parameters
----------
tpf_number: int
Index of the TPF
"""
ldx = self.tpf_meta["sources"][tpf_number]
return lk.LightCurveCollection([self.lcs[l] for l in ldx])
def batch_flatten_collection(lcs, kepid_df, method='GP', return_trend=False):
"""Batch flatten a LightCurveCollection, grouping by quarter
Parameters:
-----------
lcs: LightCurveCollection
A collection of lightcurves for a single planet host star system
kepid_df: pandas DataFrame
A pandas DataFrame containing the periods and t0 of each TCE in the
system. Uses the same column names as the DR24 catalog
method: string
Either "GP" or "spline"
return_trend: boolean
Whether or not to return the inferred trend. Default: False
"""
# Flatten all the quarters first using splines
lcs_flattened = lk.LightCurveCollection([])
lcs_trends = lk.LightCurveCollection([])
for lc_per_quarter in lcs:
lc_per_quarter = lc_per_quarter.remove_nans()
tce_mask = make_cadence_mask(lc_per_quarter, kepid_df)
if method == 'GP':
input_lc = lc_per_quarter[~tce_mask].remove_outliers()
trend = estimate_gp_mean_model(input_lc, t=lc_per_quarter.time)
if method == 'spline':
trend, knot_spacing = spline_model_comparison_BIC(
lc_per_quarter, ~tce_mask)
flattened = lc_per_quarter / trend
lcs_flattened.append(flattened)
lc_trend = lc_per_quarter.copy()
lc_trend.flux = trend
lcs_trends.append(lc_trend)
if return_trend:
return lcs_flattened, lcs_trends
else:
return lcs_flattened
def cleanup_lkfc(lkf_collection, kic):
"""
Join each quarter in a lk.LightCurveFileCollection into a single lk.LightCurveFile
Performs only the minimal detrending step remove_nans()
Parameters
----------
lkf_collection : lk.LightCurveFileCollection
kic : int
Kepler Input Catalogue (KIC) number for target
Returns
-------
lkc : lk.LightCurveCollection
"""
lkf_col = deepcopy(lkf_collection)
quarters = []
for i, lkf in enumerate(lkf_col):
quarters.append(lkf.quarter)
data_out = []
for q in np.unique(quarters):
lkf_list = []
cadno = []
for i, lkf in enumerate(lkf_col):
if (lkf.quarter == q) * (lkf.targetid == kic):
lkf_list.append(lkf)
cadno.append(lkf.cadenceno.min())
order = np.argsort(cadno)
lkfc_list = []
for j in order:
lkfc_list.append(lkf_list[j])
# the operation "stitch" converts a LightCurveFileCollection to a single LightCurve
lkfc_list = lk.LightCurveFileCollection(lkfc_list)
lklc = lkfc_list.PDCSAP_FLUX.stitch().remove_nans()
data_out.append(lklc)
return lk.LightCurveCollection(data_out)
best_fit_period = np.zeros(len(mass_id[beg_ind:end_ind]))
best_fit_uncert = np.zeros(len(mass_id[beg_ind:end_ind]))
#data_source = np.zeros(len(mass_id[beg_ind:end_ind]))
for j,i in enumerate(mass_id[beg_ind:end_ind]):
print(i)
coords = SkyCoord(ra=float(target_ra[j]), dec=float(target_dec[j]), unit=(u.deg, u.deg))
outID,outEclipLong,outEclipLat,outSec,outCam,outCcd,outColPix, outRowPix, scinfo = tess_stars2px_function_entry(j, float(target_ra[j]), float(target_dec[j]))
sector_source = [] #array of where the data came from length of the amount of sectors
#lightcurves = lk.LightCurveCollection()
for num, sector in enumerate(outSec):
if sector <= 31:
###first try to find 2-min data for this sector
try:
lc = lk.search_lightcurvefile(coords, mission='TESS', sector=sector).download().PDCSAP_FLUX.remove_nans()
if sector == outSec[0]:
lightcurves = lk.LightCurveCollection(lc)
else:
lightcurves.append(lc)
sector_source.append('2-min')
print('Sector {} downloaded with LightKurve'.format(sector))
except KeyboardInterrupt:
raise
except Exception as e:
print(e)
print('Sector {} not available with LightKurve, trying eleanor'.format(sector))
try:
###then try to see if the fits file already exists
time = []
flux = []
background = []
data = fits.open('/data/wallaby/rmorris/GALAH/all_target_lc/{}_s{}_eleanor_data.fits'.format(i,sector))
def from_eleanor(self, ticid, save_postcard=False):
"""Download light curves from Eleanor for desired target. Eleanor light
curves include:
- raw : raw flux light curve
- corr : corrected flux light curve
- pca : principle component analysis light curve
- psf : point spread function photometry light curve
Parameters
----------
ticid : int
TIC ID of desired target
Returns
-------
LightCurveCollection :
~lightkurve.LightCurveCollection containing raw and corrected light curves.
"""
'''
# BUGFIX FOR ELEANOR (DEPRICATED)
# -------------------------------
from astroquery.mast import Observations
server = 'https://mast.stsci.edu'
Observations._MAST_REQUEST_URL = server + "/api/v0/invoke"
Observations._MAST_DOWNLOAD_URL = server + "/api/v0.1/Download/file"
Observations._COLUMNS_CONFIG_URL = server + "/portal/Mashup/Mashup.asmx/columnsconfig"
'''
# search TESScut to figure out which sectors you need (there's probably a better way to do this)
sectors = self._find_sectors(ticid)
if isinstance(ticid, str):
ticid = int(re.search(r'\d+', str(ticid)).group())
self.ticid = ticid
print(
f'Creating light curve for target {ticid} for sectors {sectors}.')
# download target data for the desired source for only the first available sector
star = eleanor.Source(tic=ticid, sector=int(sectors[0]), tc=True)
try:
data = eleanor.TargetData(star,
height=11,
width=11,
bkg_size=27,
do_psf=True,
do_pca=True,
try_load=True,
save_postcard=save_postcard)
except:
data = eleanor.TargetData(star,
height=7,
width=7,
bkg_size=21,
do_psf=True,
do_pca=True,
try_load=True,
save_postcard=save_postcard)
q = data.quality == 0
# create raw flux light curve
raw_lc = lk.LightCurve(time=data.time[q],
flux=data.raw_flux[q],
flux_err=data.flux_err[q],
label='raw',
time_format='btjd').remove_nans().normalize()
corr_lc = lk.LightCurve(time=data.time[q],
flux=data.corr_flux[q],
flux_err=data.flux_err[q],
label='corr',
time_format='btjd').remove_nans().normalize()
pca_lc = lk.LightCurve(time=data.time[q],
flux=data.pca_flux[q],
flux_err=data.flux_err[q],
label='pca',
time_format='btjd').remove_nans().normalize()
psf_lc = lk.LightCurve(time=data.time[q],
flux=data.psf_flux[q],
flux_err=data.flux_err[q],
label='psf',
time_format='btjd').remove_nans().normalize()
#track breakpoints between sectors
self.breakpoints = [raw_lc.time[-1]]
# iterate through extra sectors and append the light curves
if len(sectors) > 1:
for s in sectors[1:]:
try: # some sectors fail randomly
star = eleanor.Source(tic=ticid, sector=int(s), tc=True)
data = eleanor.TargetData(star,
height=15,
width=15,
bkg_size=31,
do_psf=True,
do_pca=True,
try_load=True)
q = data.quality == 0
raw_lc = raw_lc.append(
lk.LightCurve(
time=data.time[q],
flux=data.raw_flux[q],
flux_err=data.flux_err[q],
time_format='btjd').remove_nans().normalize())
corr_lc = corr_lc.append(
lk.LightCurve(
time=data.time[q],
flux=data.corr_flux[q],
flux_err=data.flux_err[q],
time_format='btjd').remove_nans().normalize())
pca_lc = pca_lc.append(
lk.LightCurve(
time=data.time[q],
flux=data.pca_flux[q],
flux_err=data.flux_err[q],
time_format='btjd').remove_nans().normalize())
psf_lc = psf_lc.append(
lk.LightCurve(
time=data.time[q],
flux=data.psf_flux[q],
flux_err=data.flux_err[q],
time_format='btjd').remove_nans().normalize())
self.breakpoints.append(raw_lc.time[-1])
except:
continue
# store in a LightCurveCollection object and return
return lk.LightCurveCollection([raw_lc, corr_lc, pca_lc, psf_lc])
def fetch_hlsps(lc):
'''Fetches HLSPs, given a lightkurve.KeplerLightCurve
Parameters
----------
lc : lightkurve.KeplerLightCurve
Light curve to find high level science products for
Returns
-------
hlsps : lightkurve.LightCurveCollection
Collection of HLSP light curves
'''
if not isinstance(lc, lk.KeplerLightCurve):
raise ValueError('Please pass a lightkurve.KeplerLightCurve.')
v_url = ('https://archive.stsci.edu/hlsps/k2sff/'
'c{0:02d}/{1}/{2:05d}/hlsp_k2sff_k2_lightcurve_{3}-c{0:02d}_kepler_v1_llc.fits'
''.format(lc.campaign, (lc.targetid//100000)*100000, lc.targetid - (lc.targetid//100000)*100000, lc.targetid))
e_url = ('https://archive.stsci.edu/hlsps/everest/v2/'
'c{0:02d}/{1}/{2:05d}/hlsp_everest_k2_llc_{3}-c{0:02d}_kepler_v2.0_lc.fits'
''.format(lc.campaign, (lc.targetid//100000)*100000, lc.targetid - (lc.targetid//100000)*100000, lc.targetid))
s_url = ('https://archive.stsci.edu/hlsps/k2sc/v2/'
'c{0:02d}/{1}/hlsp_k2sc_k2_llc_{2}-c{0:02d}_kepler_v2_lc.fits'
''.format(lc.campaign, (lc.targetid//100000)*100000, lc.targetid))
hlsps = []
try:
hdu = fits.open(v_url)[1].data
lc1 = lk.KeplerLightCurve(hdu['T'], hdu['FCOR'], cadenceno=hdu['CADENCENO'], meta={'arclength': hdu['ARCLENGTH']},
channel=lc.channel, campaign=lc.campaign, quarter=lc.quarter,
mission=lc.mission, targetid=lc.targetid, ra=lc.ra, dec=lc.dec,
label='K2SFF (Vanderburg & Johnson)')
lc1 = lc1[np.isfinite(lc1.time)]
hlsps.append(lc1)
except HTTPError:
pass
try:
hdu = fits.open(e_url)[1].data
lc1 = lk.KeplerLightCurve(hdu['TIME'], hdu['FCOR'], cadenceno=hdu['CADN'], quality=hdu['QUALITY'],
channel=lc.channel, campaign=lc.campaign, quarter=lc.quarter,
mission=lc.mission, targetid=lc.targetid, ra=lc.ra, dec=lc.dec,
label='EVEREST (Luger)')
lc1 = lc1[((hdu['QUALITY'] & 24) == 0)]
lc1 = lc1[np.isfinite(lc1.time)]
hlsps.append(lc1)
except HTTPError:
pass
try:
hdu = fits.open(s_url)[1].data
lc1 = lk.KeplerLightCurve(hdu['time'], hdu['flux'], hdu['error'], cadenceno=hdu['cadence'], quality=hdu['quality'],
channel=lc.channel, campaign=lc.campaign, quarter=lc.quarter,
mission=lc.mission, targetid=lc.targetid, ra=lc.ra, dec=lc.dec,
label='K2SC (Aigrain)')
lc1 = lc1[np.isfinite(lc1.time)]
hlsps.append(lc1)
except HTTPError:
pass
return lk.LightCurveCollection(hlsps)
# Temporary workaround for slow MAST queries with lightkurve
observations = Observations.query_criteria(
target_name=f"{tic}",
radius=0.0001,
project=["TESS"],
obs_collection=["TESS"],
provenance_name="SPOC",
dataproduct_type="timeseries",
)
if not len(observations):
raise RuntimeError("no 2-minute cadence data")
products = Observations.get_product_list(observations)
products = products[products["productSubGroupDescription"] == "LC"]
files = Observations.download_products(
products, download_dir=tess_world.get_lightkurve_directory())
lcfs = lk.LightCurveCollection(
[lk.open(file).PDCSAP_FLUX for file in files["Local Path"]])
lc = lcfs.stitch().remove_nans()
# Extract the data in the correct format
x = np.ascontiguousarray(lc.time, dtype=np.float64)
y = np.ascontiguousarray(1e3 * (lc.flux - 1), dtype=np.float64)
yerr = np.ascontiguousarray(1e3 * lc.flux_err, dtype=np.float64)
# Plot the light curve
plt.plot(x, y, "k", linewidth=0.5)
plt.xlabel("time [days]")
plt.ylabel("relative flux [ppt]")
plt.title(f"TOI {toi_num}; TIC {tic}", fontsize=14)
# Label the transits on the plot
for n in range(num_toi):
def fit_lightcurves(
self,
plot=False,
iter_negative=False,
fit_mean_shape_model=False,
fit_va=False,
sap=False,
):
"""
Fit the sources in the data to get its light curves.
By default it only uses the per cadence PSF model to do the photometry.
Alternatively it can fit the mean-PSF and the mean-PSF with time model to
the data, this is the original method implemented in `PSFmachine` and described
in the paper. Aperture Photometry is also available by creating aperture masks
that follow the mean-PSF shape.
This function creates the `lcs` attribuite that contains a collection of light
curves in the form of `lightkurve.LightCurveCollection`. Each entry in the
collection is a `lightkurve.KeplerLightCurve` object with the different type
of photometry (PSF per cadence, SAP, mean-PSF, and mean-PSF velocity-aberration
corrected). Also each `lightkurve.KeplerLightCurve` object includes its
asociated metadata.
The photometry can also be accessed independently from the following attribuites
that `fit_lightcurves` create:
* `ws` and `werrs` have the uncorrected PSF flux and flux errors.
* `ws_va` and `werrs_va` have the PSF flux and flux errors corrected by
velocity aberration.
* `sap_flux` and `sap_flux_err` have the flux and flux errors computed
using aperture mask.
* `ws_frame` and `werrs_frame` have the flux from PSF at each cadence.
Parameters
----------
plot : bool
Whether or not to show some diagnostic plots. These can be helpful
for a user to see if the PRF and time dependent models are being calculated
correctly.
iter_negative : bool
When fitting light curves, it isn't possible to force the flux to be
positive. As such, when we find there are light curves that deviate into
negative flux values, we can clip these targets out of the analysis and
rerun the model.
If iter_negative is True, PSFmachine will run up to 3 times, clipping out
any negative targets each round. This is used when
`fit_mean_shape_model` is `True`.
fit_mean_shape_model : bool
Will do PSF photmetry using the mean-PSF.
fit_va : bool
Whether or not to fit Velocity Aberration (which implicitly will try to fit
other kinds of time variability). `fit_mean_shape_model` must set to `True`
ortherwise will be ignored. This will try to fit the "long term"
trends in the dataset. If True, this will take slightly longer to fit.
If you are interested in short term phenomena, like transits, you may
find you do not need this to be set to True. If you have the time, it
is recommended to run it.
sap : boolean
Compute or not Simple Aperture Photometry. See
`Machine.compute_aperture_photometry()` for details.
"""
# create mean shape model to be used by SAP and mean-PSF
self.build_shape_model(plot=plot, frame_index="mean")
# do SAP first
if sap:
self.compute_aperture_photometry(
aperture_size="optimal", target_complete=1, target_crowd=1
)
# do mean-PSF photometry and time model if asked
if fit_mean_shape_model:
self.build_time_model(plot=plot, downsample=True)
# fit the OG time model
self.fit_model(fit_va=fit_va)
if iter_negative:
# More than 2% negative cadences
negative_sources = (self.ws_va < 0).sum(axis=0) > (0.02 * self.nt)
idx = 1
while len(negative_sources) > 0:
self.mean_model[negative_sources] *= 0
self.fit_model(fit_va=fit_va)
negative_sources = np.where((self.ws_va < 0).all(axis=0))[0]
idx += 1
if idx >= 3:
break
# fit shape model at each cadence
self.build_frame_shape_model()
self.fit_frame_model()
self.lcs = []
for idx, s in self.sources.iterrows():
meta = {
"ORIGIN": "PSFMACHINE",
"APERTURE": "PSF + SAP" if sap else "PSF",
"LABEL": s.designation,
"MISSION": self.meta["MISSION"],
"RA": s.ra,
"DEC": s.dec,
"PMRA": s.pmra / 1000,
"PMDEC": s.pmdec / 1000,
"PARALLAX": s.parallax,
"GMAG": s.phot_g_mean_mag,
"RPMAG": s.phot_rp_mean_mag,
"BPMAG": s.phot_bp_mean_mag,
}
attrs = [
"channel",
"module",
"ccd",
"camera",
"quarter",
"campaign",
"quarter",
"row",
"column",
"mission",
]
for attr in attrs:
if attr in self.meta.keys():
meta[attr.upper()] = self.meta[attr]
lc = lk.KeplerLightCurve(
time=(self.time) * u.d,
flux=self.ws_frame[:, idx] * (u.electron / u.second),
flux_err=self.werrs_frame[:, idx] * (u.electron / u.second),
meta=meta,
time_format="jd",
)
if fit_mean_shape_model:
lc["flux_NVA"] = (self.ws[:, idx]) * u.electron / u.second
lc["flux_err_NVA"] = (self.werrs[:, idx]) * u.electron / u.second
if fit_va:
lc["flux_VA"] = (self.ws_va[:, idx]) * u.electron / u.second
lc["flux_err_VA"] = (self.werrs_va[:, idx]) * u.electron / u.second
if sap:
lc["sap_flux"] = (self.sap_flux[:, idx]) * u.electron / u.second
lc["sap_flux_err"] = (self.sap_flux_err[:, idx]) * u.electron / u.second
self.lcs.append(lc)
self.lcs = lk.LightCurveCollection(self.lcs)
return
lc = tpf.to_lightcurve(aperture_mask=tpf.pipeline_mask)
flat, trend = lc.flatten(window_length=301, return_trend=True)
lcs.append(lc)
flat_lcs.append(flat)
trend_lcs.append(trend)
#lc.plot()
#plt.show();
def my_custom_corrector_func(lc):
corrected_lc = lc.normalize().flatten(window_length=401)
return corrected_lc
lc = lk.LightCurveCollection(
lcs).stitch() #corrector_func=my_custom_corrector_func)
#lc = lcfs.PDCSAP_FLUX.stitch()
#lc.plot()
#plt.show()
#lc.scatter()
#plt.show()
flat = lk.LightCurveCollection(flat_lcs).stitch()
trend = lk.LightCurveCollection(trend_lcs).stitch()
#flat, trend = lc.flatten(window_length=301, return_trend=True)
ax = lc.errorbar(label=args.star) # plot() returns a matplotlib axes ...
trend.plot(ax=ax, color='red', lw=2, label='Trend')
# which we can pass to the next plot() to use the same axes
plt.show()
flat.errorbar(label=args.star)
def SIP(tpfs,
sigma=5,
min_period=10,
max_period=100,
nperiods=300,
npca_components=2,
aperture_threshold=3,
sff=False,
sff_kwargs={}):
"""
Systematics-insensitive periodogram for finding periods in long period NASA's TESS data.
SIP can be used to find the best fitting sinusoid period in long period TESS data, while
mitigating the instrument and scattered light background systematics.
A description of the concepts behind a SIP is given here in the context of K2 data:
https://ui.adsabs.harvard.edu/abs/2016ApJ...818..109A/abstract
Parameters
----------
tpfs : lightkurve.TargetPixelFileCollection
A collection of target pixel files from the TESS mission. This can be
generated using lightkurve's search functions, for example:
tpfs = lk.search_targetpixelfile('TIC 288735205', mission='tess').download_all()
sigma : int or float
SIP will run a single first iteration at a period of 27 days to remove significant
outliers. Set sigma to a value, above which outliers will be clipped
min_period : float
The minimum period for the periodogram
max_period : float
The maximum period for the periodogram
nperiods : int
The number of periods to fit
npca_components : int
Number of pca components to detrend with. Default is 2.
aperture_threshold : float
If there is no aperture mask from the pipeline, will create one. Set
aperture_threshold to set the thresholding for the aperture creation.
(See lightkurve's create_threshold_mask function.)
sff : boolean
Whether to run SFF detrending simultaneously. This is most useful for K2 data.
When True, will run SFF detrending.
sff_kwargs : dict
Dictionary of SFF key words to pass. See lightkurve's SFFCorrector.
Returns
-------
r : dict
Dictionary containing the following entries:
periods: the periods evaluated
power: the power at each period (definite as the amplitude of the sinusoid)
raw_lc: the original light curve from the input target pixel files
corr_lc: the light curve with the best fitting systematics removed
period_at_max_power: the best fit period of the sinusoid.
power_bkg: the power at each period for the pixels -outside- the aperture
raw_lc_bkg: the background light curve (pixels outside aperture)
"""
# Get the un-background subtracted data
if hasattr(tpfs[0], 'flux_bkg'):
tpfs_uncorr = [(tpf + np.nan_to_num(tpf.flux_bkg.value))[np.isfinite(
np.nansum(tpf.flux_bkg.value, axis=(1, 2)))] for tpf in tpfs]
else:
tpfs_uncorr = tpfs
apers = [
tpf.pipeline_mask if tpf.pipeline_mask.any() else
tpf.create_threshold_mask(aperture_threshold) for tpf in tpfs_uncorr
]
bkg_apers = [(~aper) & (np.nansum(tpf.flux, axis=0) != 0)
for aper, tpf in zip(apers, tpfs_uncorr)]
lc = lk.LightCurveCollection([
tpf.to_lightcurve(aperture_mask=aper)
for tpf, aper in zip(tpfs_uncorr, apers)
]).stitch(lambda x: x).normalize()
lc.flux_err.value[~np.isfinite(lc.flux_err.value)] = np.nanmedian(
lc.flux_err.value)
# Run the same routines on the background pixels
lc_bkg = lk.LightCurveCollection([
tpf.to_lightcurve(aperture_mask=bkg_aper)
for tpf, bkg_aper in zip(tpfs_uncorr, bkg_apers)
]).stitch(lambda x: x).normalize()
lc_bkg.flux_err.value[~np.isfinite(lc_bkg.flux_err.value)] = np.nanmedian(
lc_bkg.flux_err.value)
with warnings.catch_warnings():
warnings.simplefilter('ignore')
bkgs = [
lk.correctors.DesignMatrix(
tpf.flux.value[:, bkg_aper],
name='bkg').pca(npca_components).append_constant().to_sparse()
for tpf, bkg_aper in zip(tpfs_uncorr, bkg_apers)
]
for bkg in bkgs:
bkg.prior_mu[-1] = 1
bkg.prior_sigma[-1] = 0.1
bkg.prior_mu[:-1] = 0
bkg.prior_sigma[:-1] = 0.1
# Split at the datadownlink
bkgs = [
bkg.split(list((np.where(np.diff(tpf.time.jd) > 0.3)[0] + 1)))
for bkg, tpf in zip(bkgs, tpfs_uncorr)
]
systematics_dm = vstack(bkgs)
sigma_f_inv = sparse.csr_matrix(1 / lc.flux_err.value[:, None]**2)
def fit_model(lc, mask=None, return_model=False):
if mask is None:
mask = np.ones(len(lc.flux.value), bool)
sigma_w_inv = dm.X[mask].T.dot(dm.X[mask].multiply(
sigma_f_inv[mask])).toarray()
sigma_w_inv += np.diag(1. / dm.prior_sigma**2)
B = dm.X[mask].T.dot(
(lc.flux.value[mask] / lc.flux_err.value[mask]**2))
B += dm.prior_mu / dm.prior_sigma**2
w = np.linalg.solve(sigma_w_inv, B)
with warnings.catch_warnings():
warnings.simplefilter('ignore')
werr = ((np.linalg.inv(sigma_w_inv))**0.5).diagonal()
if return_model:
return dm.X.dot(w)
return w, werr
# Make a dummy design matrix
period = 27
ls_dm = lk.correctors.DesignMatrix(
lombscargle.implementations.mle.design_matrix(lc.time.jd,
frequency=1 / period,
bias=False,
nterms=1),
name='LS').to_sparse()
dm = lk.correctors.SparseDesignMatrixCollection(
[systematics_dm, ls_dm]).to_designmatrix(name='design_matrix')
if sff:
sff_dm = []
for tpf in tpfs_uncorr:
s = lk.correctors.SFFCorrector(tpf.to_lightcurve())
_ = s.correct(**sff_kwargs)
sff_dm.append(s.dmc['sff'].to_sparse())
sff_dm = vstack(sff_dm)
dm = lk.correctors.SparseDesignMatrixCollection(
[dm, sff_dm]).to_designmatrix(name='design_matrix')
# Do a first pass at 27 days, just to find ridiculous outliers
mod = fit_model(lc, return_model=True)
mask = ~(lc - mod * lc.flux.unit).remove_outliers(return_mask=True,
sigma=sigma)[1]
# Loop over some periods we care about
periods = 1 / np.linspace(1 / min_period, 1 / max_period, nperiods)
ws = np.zeros((len(periods), dm.X.shape[1]))
ws_err = np.zeros((len(periods), dm.X.shape[1]))
ws_bkg = np.zeros((len(periods), dm.X.shape[1]))
ws_err_bkg = np.zeros((len(periods), dm.X.shape[1]))
for idx, period in enumerate(
tqdm(periods, desc='Running pixels in aperture')):
dm.X[:,
-ls_dm.shape[1]:] = lombscargle.implementations.mle.design_matrix(
lc.time.jd, frequency=1 / period, bias=False, nterms=1)
ws[idx], ws_err[idx] = fit_model(lc, mask=mask)
ws_bkg[idx], ws_err_bkg[idx] = fit_model(lc_bkg, mask=mask)
power = (ws[:, -2]**2 + ws[:, -1]**2)**0.5
am = np.argmax(power)
dm.X[:, -ls_dm.shape[1]:] = lombscargle.implementations.mle.design_matrix(
lc.time.jd, frequency=1 / periods[am], bias=False, nterms=1)
mod = dm.X[:, :-2].dot(ws[am][:-2])
power_bkg = (ws_bkg[:, -2]**2 + ws_bkg[:, -1]**2)**0.5
r = {
'periods': periods,
'power': power,
'raw_lc': lc,
'power_bkg': power_bkg,
'raw_lc_bkg': lc_bkg,
'corr_lc': lc - mod * lc.flux.unit + 1,
'period_at_max_power': periods[am]
}
return r
def fit_lightcurves(
self,
plot=False,
fit_va=True,
iter_negative=True,
load_shape_model=False,
shape_model_file=None,
sap=True,
):
"""
Fit the sources inside the TPFs passed to `TPFMachine`.
This function creates the `lcs` attribuite that contains a collection of light
curves in the form of `lightkurve.LightCurveCollection`. Each entry in the
collection is a `lightkurve.KeplerLightCurve` object with the different type
of photometry (SAP, PSF, and PSF velocity-aberration corrected). Also each
`lightkurve.KeplerLightCurve` object includes its asociated metadata.
The photometry can also be accessed independently from the following attribuites
that `fit_lightcurves` create:
* `ws` and `werrs` have the uncorrected PSF flux and flux errors.
* `ws_va` and `werrs_va` have the PSF flux and flux errors corrected by
velocity aberration.
* `sap_flux` and `sap_flux_err` have the flux and flux errors computed
using aperture mask.
Parameters
----------
plot : bool
Whether or not to show some diagnostic plots. These can be helpful
for a user to see if the PRF and time dependent models are being calculated
correctly.
fit_va : bool
Whether or not to fit Velocity Aberration (which implicitly will try to fit
other kinds of time variability). This will try to fit the "long term"
trends in the dataset. If True, this will take slightly longer to fit.
If you are interested in short term phenomena, like transits, you may
find you do not need this to be set to True. If you have the time, it
is recommended to run it.
iter_negative : bool
When fitting light curves, it isn't possible to force the flux to be
positive.
As such, when we find there are light curves that deviate into negative flux
values, we can clip these targets out of the analysis and rerun the model.
If iter_negative is True, PSFmachine will run up to 3 times, clipping out
any negative targets each round.
load_shape_model : bool
Load PRF shape model from disk or not. Default models were computed from
FFI of the same channel and quarter.
shape_model_file : string
Path to PRF model file to be passed to `load_shape_model(input)`. If None,
then precomputed models will be download from Zenodo repo.
sap : boolean
Compute or not Simple Aperture Photometry. See
`Machine.compute_aperture_photometry()` for details.
"""
# use PRF model from FFI or create one with TPF data
if load_shape_model:
self.load_shape_model(input=shape_model_file, plot=plot)
else:
self.build_shape_model(plot=plot)
# sap photometry is independent of the time model and fitting the PSF model.
# it only uses the shape mean_model
if sap:
self.compute_aperture_photometry(aperture_size="optimal",
target_complete=1,
target_crowd=1)
self.build_time_model(plot=plot)
self.fit_model(fit_va=fit_va)
if iter_negative:
# More than 2% negative cadences
negative_sources = (self.ws_va < 0).sum(axis=0) > (0.02 * self.nt)
idx = 1
while len(negative_sources) > 0:
self.mean_model[negative_sources] *= 0
self.fit_model(fit_va=fit_va)
negative_sources = np.where((self.ws_va < 0).all(axis=0))[0]
idx += 1
if idx >= 3:
break
self.lcs = []
for idx, s in self.sources.iterrows():
meta = self._make_meta_dict(idx, s, sap)
if fit_va:
flux, flux_err = (
(self.ws_va[:, idx]) * u.electron / u.second,
self.werrs_va[:, idx] * u.electron / u.second,
)
else:
flux, flux_err = (
(self.ws[:, idx]) * u.electron / u.second,
self.werrs[:, idx] * u.electron / u.second,
)
lc = lk.KeplerLightCurve(
time=(self.time) * u.d,
flux=flux,
flux_err=flux_err,
meta=meta,
time_format="jd",
)
if fit_va:
lc["psf_flux_NVA"] = (self.ws[:, idx]) * u.electron / u.second
lc["psf_flux_err_NVA"] = (
self.werrs[:, idx]) * u.electron / u.second
if sap:
lc["sap_flux"] = (self.sap_flux[:,
idx]) * u.electron / u.second
lc["sap_flux_err"] = (
self.sap_flux_err[:, idx]) * u.electron / u.second
self.lcs.append(lc)
self.lcs = lk.LightCurveCollection(self.lcs)
return