def from_grid(cls, grid, **pca_kwargs):
"""
Create an Emulator using PCA decomposition from a GridInterface.
Parameters
----------
grid : :class:`GridInterface` or str
The grid interface to decompose
pca_kwargs : dict, optional
The keyword arguments to pass to PCA. By default, `n_components=0.99` and
`svd_solver='full'`.
See Also
--------
sklearn.decomposition.PCA
"""
# Load grid if a string is given
if isinstance(grid, str):
grid = HDF5Interface(grid)
fluxes = np.array(list(grid.fluxes))
# Normalize to an average of 1 to remove uninteresting correlation
flux_scalar = fluxes.mean(1, keepdims=True)
fluxes /= flux_scalar
# Center and whiten
flux_mean = fluxes.mean(0)
fluxes -= flux_mean
flux_std = fluxes.std(0)
fluxes /= flux_std
# Perform PCA using sklearn
default_pca_kwargs = dict(n_components=0.99, svd_solver="full")
default_pca_kwargs.update(pca_kwargs)
pca = PCA(**default_pca_kwargs)
weights = pca.fit_transform(fluxes)
eigenspectra = pca.components_
exp_var = pca.explained_variance_ratio_.sum()
# This is basically the mean square error of the reconstruction
log.info(
f"PCA fit {exp_var:.2f}% of the variance with {pca.n_components_:d} components."
)
w_hat = get_w_hat(eigenspectra, fluxes)
emulator = cls(
grid_points=grid.grid_points,
param_names=grid.param_names,
wavelength=grid.wl,
weights=weights,
eigenspectra=eigenspectra,
w_hat=w_hat,
flux_mean=flux_mean,
flux_std=flux_std,
flux_scalar=flux_scalar,
)
return emulator
)
args = parser.parse_args()
import matplotlib.pyplot as plt
import multiprocessing as mp
import numpy as np
import itertools
import Starfish
from Starfish import emulator
from Starfish.grid_tools import HDF5Interface
from Starfish.emulator import PCAGrid, Gprior, Glnprior, Emulator
from Starfish.covariance import Sigma
import os
if args.create:
myHDF5 = HDF5Interface()
my_pca = PCAGrid.create(myHDF5)
my_pca.write()
if args.plot == "reconstruct":
my_HDF5 = HDF5Interface()
my_pca = PCAGrid.open()
recon_fluxes = my_pca.reconstruct_all()
# we need to apply the same normalization to the synthetic fluxes that we
# used for the reconstruction
fluxes = np.empty((my_pca.M, my_pca.npix))
for i, spec in enumerate(my_HDF5.fluxes):
fluxes[i, :] = spec
def initialize(self, key):
'''
Initialize to the correct chunk of data (echelle order).
:param key: (spectrum_id, order_key)
:param type: (int, int)
This method should only be called after all subprocess have been forked.
'''
self.id = key
spectrum_id, self.order_key = self.id
# Make sure these are ints
self.spectrum_id = int(spectrum_id)
self.instrument = Instruments[self.spectrum_id]
self.dataSpectrum = DataSpectra[self.spectrum_id]
self.wl = self.dataSpectrum.wls[self.order_key]
self.fl = self.dataSpectrum.fls[self.order_key]
self.sigma = self.dataSpectrum.sigmas[self.order_key]
self.ndata = len(self.wl)
self.mask = self.dataSpectrum.masks[self.order_key]
self.order = int(self.dataSpectrum.orders[self.order_key])
self.logger = logging.getLogger("{} {}".format(self.__class__.__name__,
self.order))
if self.debug:
self.logger.setLevel(logging.DEBUG)
else:
self.logger.setLevel(logging.INFO)
self.logger.info("Initializing model on Spectrum {}, order {}.".format(
self.spectrum_id, self.order_key))
self.npoly = Starfish.config["cheb_degree"]
self.chebyshevSpectrum = ChebyshevSpectrum(self.dataSpectrum,
self.order_key,
npoly=self.npoly)
# If the file exists, optionally initiliaze to the chebyshev values
fname = Starfish.specfmt.format(self.spectrum_id,
self.order) + "phi.json"
if os.path.exists(fname):
self.logger.debug("Loading stored Chebyshev parameters.")
phi = PhiParam.load(fname)
self.chebyshevSpectrum.update(phi.cheb)
self.resid_deque = deque(
maxlen=500
) #Deque that stores the last residual spectra, for averaging
self.counter = 0
self.interpolator = Interpolator(self.wl, HDF5Interface())
self.flux = None # Where the interpolator will store the flux
self.wl_FFT = self.interpolator.wl
# The raw eigenspectra and mean flux components
self.ss = np.fft.rfftfreq(len(self.wl_FFT),
d=self.interpolator.interface.dv)
self.ss[0] = 0.01 # junk so we don't get a divide by zero error
self.sigma_mat = self.sigma**2 * np.eye(self.ndata)
self.lnprior = 0.0 # Modified and set by NuisanceSampler.lnprob
# self.nregions = 0
# self.exceptions = []
# Update the outdir based upon id
self.noutdir = Starfish.routdir + "{}/{}/".format(
self.spectrum_id, self.order)
I notice a difference in the flux level of starfish spectra compared to the manually loaded spectra.
Investigating that here.
"""
import os
import matplotlib.pyplot as plt
import numpy as np
from Starfish.grid_tools import HDF5Interface
from astropy.io import fits
from spectrum_overload import Spectrum
import simulators
myHDF5 = HDF5Interface()
wl = myHDF5.wl
params = [6100, 4.5, 0.0]
flux = myHDF5.load_flux(np.array(params))
# Load direct phoenix spectra
path = simulators.starfish_grid["raw_path"]
phoenix = os.path.join(
path, "Z-0.0",
"lte{:05d}-{:0.2f}-0.0.PHOENIX-ACES-AGSS-COND-2011-HiRes.fits".format(
params[0], params[1]))
phoenix_wav = os.path.join(path, "WAVE_PHOENIX-ACES-AGSS-COND-2011.fits")
print(phoenix)
cfg = yaml.load(f)
f.close()
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.ticker import FormatStrFormatter as FSF
from matplotlib.ticker import MaxNLocator
from matplotlib.ticker import MultipleLocator
from Starfish.grid_tools import HDF5Interface
from Starfish.emulator import PCAGrid
pcagrid = PCAGrid.from_cfg(cfg)
ind = pcagrid.ind
#Make sure that we can get the same indices from the main grid.
grid = HDF5Interface(cfg["grid"], ranges=cfg["ranges"])
wl = grid.wl[ind]
temps = np.unique(pcagrid.gparams[:,0])
loggs = np.unique(pcagrid.gparams[:,1])
Zs = np.unique(pcagrid.gparams[:,2])
points = {"temp":temps, "logg":loggs, "Z":Zs}
base = cfg['outdir']
# Plot the eigenspectra
for i,comp in enumerate(pcagrid.pcomps):
print("plotting {}".format(i))
fig = plt.figure(figsize=(8, 5))
ax = fig.add_subplot(111)
def from_cfg(cls, cfg):
'''
:param cfg: dictionary containing the parameters.
'''
grid = HDF5Interface(cfg["grid"], ranges=cfg["ranges"])
wl = grid.wl
min_v = grid.wl_header["min_v"]
if 'wl' in cfg:
low, high = cfg['wl']
ind = determine_chunk_log(
wl, low, high) #Sets the wavelength vector using a power of 2
wl = wl[ind]
else:
ind = np.ones_like(wl, dtype="bool")
npix = len(wl)
m = len(grid.list_grid_points)
test_index = cfg['test_index']
if test_index < m:
#If the index actually corresponds to a spectrum in the grid, we're dropping it out. Otherwise,
#leave it in by simply setting test_index to something larger than the number of spectra in the grid.
m -= 1
fluxes = np.empty((m, npix))
z = 0
for i, spec in enumerate(grid.fluxes):
if i == test_index:
test_spectrum = spec[ind]
continue
fluxes[z, :] = spec[ind]
z += 1
#Normalize all of the fluxes to an average value of 1
#In order to remove interesting correlations
fluxes = fluxes / np.average(fluxes, axis=1)[np.newaxis].T
#Subtract the mean from all of the fluxes.
flux_mean = np.average(fluxes, axis=0)
fluxes -= flux_mean
#"Whiten" each spectrum such that the variance for each wavelength is 1
flux_std = np.std(fluxes, axis=0)
fluxes /= flux_std
pca = PCA()
pca.fit(fluxes)
comp = pca.transform(fluxes)
components = pca.components_
mean = pca.mean_
print("Shape of PCA components {}".format(components.shape))
if not np.allclose(mean, np.zeros_like(mean)):
import sys
sys.exit(
"PCA mean is more than just numerical noise. Something's wrong!"
)
#Otherwise, the PCA mean is just numerical noise that we can ignore.
ncomp = cfg['ncomp']
print("Keeping only the first {} components".format(ncomp))
pcomps = components[0:ncomp]
gparams = np.empty((m, 3))
z = 0
for i, params in enumerate(grid.list_grid_points):
if i == test_index:
test_params = np.array(
[params["temp"], params["logg"], params["Z"]])
continue
gparams[z, :] = np.array(
[params["temp"], params["logg"], params["Z"]])
z += 1
#Create w
w = np.empty((ncomp, m))
for i, pcomp in enumerate(pcomps):
for j, spec in enumerate(fluxes):
w[i, j] = np.sum(pcomp * spec)
pca = cls(wl, min_v, flux_mean, flux_std, pcomps, w, gparams)
pca.ind = ind
return pca
I notice a difference in the flux level of starfish spectra compared to the manually loaded spectra.
Investigating that here.
"""
import os
import Starfish
import matplotlib.pyplot as plt
import numpy as np
from Starfish.grid_tools import HDF5Interface
from astropy.io import fits
import simulators
myHDF5 = HDF5Interface(
filename=
"/home/jneal/Phd/Codes/companion_simulations/starfish_tests/libraries/PHOENIX_50k.hdf5"
)
myHDF5_air = HDF5Interface(
filename=
"/home/jneal/Phd/Codes/companion_simulations/starfish_tests/libraries/PHOENIX_air.hdf5"
)
myHDF5_norm_air = HDF5Interface(
filename=
"/home/jneal/Phd/Codes/companion_simulations/starfish_tests/libraries/PHOENIX_norm_air.hdf5"
)
myHDF5_norm = HDF5Interface(
filename=
"/home/jneal/Phd/Codes/companion_simulations/starfish_tests/libraries/PHOENIX_norm.hdf5"
)
wl = myHDF5.wl
wl_air = myHDF5_air.wl
#!/usr/bin/env python # Test reading hdf5 file that I created import numpy as np from Starfish.grid_tools import HDF5Interface my_hdf5 = HDF5Interface() wl = my_hdf5.wl flux = my_hdf5.load_flux(np.array([6100, 4.5, 0.0]))
def load_starfish_spectrum(params,
limits=None,
hdr=False,
normalize=False,
area_scale=False,
flux_rescale=False,
wav_scale=True):
"""Load spectrum from hdf5 grid file.
Parameters
----------
params: list
Model parameters [teff, logg, Z]
limits= List[float, float] default=None
Wavelength limits.
hdr: bool
Include the model header. Default False.
normalize: bool
Locally normalize the spectrum. Default False.
area_scale: bool
Multiply by stellar surface area pi*R**2 (towards Earth)
flux_rescale: bool
Convert from /cm to /nm by dividing by 1e7
wav_scale: bool
Multiply by wavelength to turn into [erg/s/cm^2]
Returns
-------
spec: Spectrum
The loaded spectrum as Spectrum object.
"""
my_hdf5 = HDF5Interface()
my_hdf5.wl = my_hdf5.wl / 10 # Turn into Nanometer
if hdr:
flux, myhdr = my_hdf5.load_flux_hdr(np.array(params))
spec = Spectrum(flux=flux, xaxis=my_hdf5.wl, header=myhdr)
else:
flux = my_hdf5.load_flux(np.array(params))
spec = Spectrum(flux=flux, xaxis=my_hdf5.wl)
if flux_rescale:
spec = spec * 1e-7 # convert flux unit from /cm to /nm
if area_scale:
if hdr:
emitting_area = phoenix_area(spec.header)
spec = spec * emitting_area
spec.header["emit_area"] = (emitting_area, "pi*r^2")
else:
raise ValueError("No header provided for stellar area scaling")
if wav_scale:
# Convert into photon counts, (constants ignored)
spec = spec * spec.xaxis
if normalize:
spec = spec_local_norm(spec, method="exponential")
if limits is not None:
if limits[0] > spec.xaxis[-1] or limits[-1] < spec.xaxis[0]:
logging.warning(
"Warning: The wavelength limits do not overlap the spectrum."
"There is no spectrum left... Check your wavelength, or limits."
)
spec.wav_select(*limits)
return spec
def mock_hdf5_interface(mock_hdf5):
yield HDF5Interface(mock_hdf5)
if args.plot:
# Check to make sure the file exists
import os
hdf5_path = os.path.expandvars(Starfish.grid["hdf5_path"])
if not os.path.exists(hdf5_path):
print(
"HDF5 file does not yet exist. Please run `grid.py create` first.")
import sys
sys.exit()
import multiprocessing as mp
import matplotlib.pyplot as plt
from Starfish.grid_tools import HDF5Interface
interface = HDF5Interface()
par_fluxes = zip(interface.grid_points, interface.fluxes)
# Define the plotting function
def plot(par_flux):
par, flux = par_flux
fig, ax = plt.subplots(nrows=1, figsize=(8, 6))
ax.plot(interface.wl, flux)
ax.set_xlabel(r"$\lambda$ [AA]")
ax.set_ylabel(r"$f_\lambda$")
fmt = "=".join(["{:.2f}" for i in range(len(Starfish.parname))])
name = fmt.format(*[p for p in par])
fig.savefig(Starfish.config["plotdir"] + "g" + name + ".png")
plt.close("all")