The Code (API)
pacman
s00_table
- class pacman.s00_table.MetaClass[source]
Bases:
object
A Class which will contain all the metadata of the analysis.
- pacman.s00_table.run00(eventlabel: str, pcf_path: Optional[Path] = PosixPath('/home/docs/checkouts/readthedocs.org/user_builds/pacmandocs/checkouts/latest/docs/source'))[source]
This function does the initial setup of the analysis, including creating a table with information on the observations. This table will be saved into ‘filelist.txt’.
Steps:
Creates a MetaData object
Creates a new run directory with the following form, e.g.: ./run/run_2021-01-01_12-34-56_eventname/
Copy and pastes the control file (obs_par.pcf) and the fit parameters file (fit_par.txt) into the new directory
Reads in all fits files and creates a table which will be saved in filelist.txt.
Saves metadata into a file called something like ./run/run_2021-01-01_12-34-56_eventname/WFC3_eventname_Meta_Save.dat
The information listed in filelist.txt are:
filenames: The name of the observational file (the file will end with .ima)
instr: The specific filter or grism used in this observation (taken from the header)
ivisit: The visit number when the observation was taken (will be calculated in s00)
iorbit: The orbit number when the observation was taken (will be calculated in s00)
t_mjd: Mid exposure time (exposure start and end is taken from the header)
t_visit: Time elapsed since the first exposure in the visit
t_orbit: Time elapsed since the first exposure in the visit
scan: Scan direction (0: forward - lower flux, 1: reverse - higher flux, -1: postarg2=0)
exp: Exposure time
Note
We use the following approach to determine the visit and orbit number:
if two exposures arent in the same orbit and more than an orbital period apart -> not subsequent orbits but a new visit
if two exposures are more than 10 min apart but less than an orbital period -> subsequent orbits
else: two exposures less than 10 mins apart -> same orbit and same visit
Note
We use the following approach to determine the scan direction:
if postarg2 < 0 –> scans[i] = 1 –> reverse scan
if postarg2 == 0 –> scans[i] = -1 –> no scan direction given
else: –> scans[i] = 0 –> forward scan
- Parameters:
- eventlabel: str
The label given to the event in the run script. Will determine the name of the run directory
- Returns:
- meta
Meta object with all the meta data stored in s00
s01_horizons
- pacman.s01_horizons.run01(eventlabel, workdir: Path, meta=None)[source]
This function downloads the location of HST during the observations.
Retrieves vector data of Hubble from JPL’s HORIZONS system on https://ssd.jpl.nasa.gov/horizons_batch.cgi (see Web interface on https://ssd.jpl.nasa.gov/horizons.cgi) Based on a perl script found on https://renenyffenegger.ch/notes/Wissenschaft/Astronomie/Ephemeriden/JPL-Horizons Also helpful: https://github.com/kevin218/POET/blob/master/code/doc/spitzer_Horizons_README.txt
txt file with HST positions in space will be saved in ./run/run_2021-01-01_12-34-56_eventname/ancil/horizons
Warning
This step needs an internet connection!
- Parameters:
- eventlabelstr
the label given to the event in the run script. Will determine the name of the run directory
- workdirstr
the name of the work directory.
- meta
the name of the metadata file
- Returns:
- meta
meta object with all the meta data stored in s00
s02_barycorr
- pacman.s02_barycorr.run02(eventlabel: str, workdir: Path, meta=None)[source]
Performs the barycentric correction of the observation times
performs the barycentric correction based on the t_mjd in filelist.txt.
Adds another column to filelist.txt called t_bjd
Plots will be saved in ./run/run_2021-01-01_12-34-56_eventname/ancil/horizons
- Parameters:
- eventlabelstr
the label given to the event in the run script. Will determine the name of the run directory
- workdirstr
the name of the work directory.
- meta
the name of the metadata file
- Returns:
- meta
meta object with all the meta data stored in s01
Notes
- History:
Written by Sebastian Zieba December 2021
s03_refspectra
- pacman.s03_refspectra.run03(eventlabel: str, workdir: Path, meta=None)[source]
Retrieves the bandpass (G102 or G141) and the stellar spectrum and takes the product to create a reference spectrum.
Options for the stellar model: - Blackbody - k93models - ck04models - phoenix
The last three stellar models are retrieved from https://archive.stsci.edu/hlsps/reference-atlases/cdbs/grid/
- Parameters:
- eventlabelstr
The label given to the event in the run script. Will determine the name of the run directory
- workdirstr
The name of the work directory.
- meta
The name of the metadata file.
- Returns:
- meta
Meta object with all the meta data stored in s02.
Notes
- History:
Written by Sebastian Zieba December 2021
s10_direct_images
This code computes the mean position of the direct image for each visit
s20_extract
s21_bin_spectroscopic_lc
This code reads in the optimally extracted lightcurve and bins it into channels 5 pixels wide, following Berta ‘12
s30_run
lib
lib.util
- pacman.lib.util.ancil(meta, s10: Optional[bool] = False, s20: Optional[bool] = False)[source]
This function loads in a lot of useful arrays and values into meta.
The following additional information are being loading into meta:
norbit: number of orbits
nvisit: number of visits
files_sp: all spectra files
files_di: all direct image files
ra: RA of the target in radians (from the header) (Note: this data is taken from the first spectrum file)
dec: DEC of the target in radians (from the header) (Note: this data is taken from the first spectrum file)
coordtable: a list of files containing the vector information of HST downloaded in s01
- Parameters:
- meta
metadata object
- s10: bool
Is set to True when s10 is being performed
- s20: bool
Is set to True when s20 is being performed
- Returns:
- meta
metadata object
Notes
- History:
Written by Sebastian Zieba December 2021
- pacman.lib.util.append_fit_output(fit, meta, fitter=None, medians=None)[source]
Appends fit statistics like rms or chi2 into meta lists.
- pacman.lib.util.computeRMS(data, maxnbins=None, binstep=1, isrmserr=False)[source]
COMPUTE ROOT-MEAN-SQUARE AND STANDARD ERROR OF DATA FOR VARIOUS BIN SIZES Taken from POET: https://github.com/kevin218/POET/blob/master/code/lib/correlated_noise.py
- pacman.lib.util.correct_wave_shift_fct_0(meta, orbnum, cmin, cmax, spec_opt, i)[source]
Use the reference spectrum for the wave cal.
- pacman.lib.util.correct_wave_shift_fct_00(meta, orbnum, cmin, cmax, spec_opt, i)[source]
Use the first exposure in the visit for wave cal.
- pacman.lib.util.correct_wave_shift_fct_0_lin(meta, orbnum, cmin, cmax, spec_opt, i)[source]
Use the reference spectrum for the wave cal.
- pacman.lib.util.correct_wave_shift_fct_1(meta, orbnum, cmin, cmax, spec_opt, x_data_firstexpvisit, y_data_firstexpvisit, i)[source]
- pacman.lib.util.correct_wave_shift_fct_1_lin(meta, orbnum, cmin, cmax, spec_opt, x_data_firstexpvisit, y_data_firstexpvisit, i)[source]
- pacman.lib.util.create_res_dir(meta)[source]
Creates the result directory depending on which fitters were used.
- pacman.lib.util.di_reformat(meta)[source]
This function was introduced because some observations have several DIs per orbit. The user can set in the pcf how they want to determine the DI target position in this case.
- pacman.lib.util.format_params_for_Model(theta, params, nvisit, fixed_array, tied_array, free_array)[source]
- pacman.lib.util.gaussian_kernel(meta, x, y)[source]
Performs a gaussian kernel over an array. Used in smoothing of the stellar spectrum. Taken from: https://stackoverflow.com/questions/24143320/gaussian-sum-filter-for-irregular-spaced-points.
- pacman.lib.util.get_wave_grid(meta)[source]
Gets grid of wavelength solutions for each orbit and row.
- pacman.lib.util.log_run_setup(meta)[source]
Prepares lists in meta where fit statistics will be saved into.
- pacman.lib.util.make_lsq_rprs_txt(vals, errs, idxs, meta)[source]
Saves the rprs vs wvl as a txt file as resulting from the lsq.
- pacman.lib.util.make_rprs_txt(vals, errs_lower, errs_upper, meta, fitter=None)[source]
Saves the rprs vs wvl as a txt file as resulting from the sampler.
- pacman.lib.util.median_abs_dev(vec)[source]
Used to determine the variance for the background count estimate.
- pacman.lib.util.read_fitfiles(meta)[source]
Read in the files (white or spectroscopic) which will be fitted.
- pacman.lib.util.readfiles(meta)[source]
Reads in the files saved in datadir and saves them into a list.
- Parameters:
- meta
Metadata object’
- Returns:
- meta
Metadata object but adds segment_list to metadata containing the sorted data fits files.
Notes
- History:
Written by Sebastian Zieba December 2021
- pacman.lib.util.return_free_array(nvisit, fixed_array, tied_array)[source]
Reads in the fit_par.txt and determines which parameters are free.
- pacman.lib.util.save_allandata(binsz, rms, stderr, meta, fitter=None)[source]
Saves the data used to create the Allan deviation plot.
- pacman.lib.util.save_fit_output(fit, data, meta)[source]
Saves all the fit statistics like rms or chi2 into an astropy table.
lib.read_pcf
This class loads a PACMAN control file (pcf) and lets you querry the parameters and values.
Constructor Parameters
- filepathlib.Path
A control file containing the parameters and values.
Notes
A parameter can have one or more values, differet parameters can have different number of values.
The function Param.get(index) automatically interprets the type of the values. If they can be cast into a numeric value retuns a numeric value, otherwise returns a string.
Examples
# Load a pcf file >>> import reader3 as rd >>> reload(rd) >>> pcf = rd.Pcffile(‘/home/patricio/ast/esp01/anal/wa011bs11/run/wa011bs11.pcf’)
# Each parameter has the attribute value, wich is a ndarray: >>> pcf.planet.value …array([‘wa011b’], dtype=’|S6’)
# To get the n-th value of a parameter use pcffile.param.get(n): # if it can’t be converted to a number/bool/etc, it returns a string. >>> pcf.planet.get(0) … ‘wa011b’
>>> pcf.photchan.get(0)
... 1
>>> pcf.fluxunits.get(0)
... True
# Use pcffile.param.value[n] to get the n-th value as string: >>> pcf.aorname.get(0) … 38807808
>>> pcf.aorname.value[0]
... '38807808'
# The function pcffile.param.getarr() returns the numeric/bool/etc # values of a parameter as a nparray: >>> pcf.sigma.value … array([‘4.0’, ‘4.0’], dtype=’|S5’)
>>> pcf.sigma.getarr()
... array([4.0, 4.0], dtype=object)
Modification History
- 2009-01-02 chris Initial Version.
by Christopher Campo ccampo@gmail.com
- 2010-03-08 patricio Modified from ccampo version.
by Patricio Cubillos pcubillos@fulbrightmail.org
2010-10-27 patricio Docstring updated 2011-02-12 patricio Merged with ccampo’s tepclass.py 2021-12 Sebastian Zieba Updated for PACMAN usage
- class pacman.lib.read_pcf.Param(vals: Any)[source]
Bases:
object
Methods
get
([index])Return a numeric/boolean/None/etc.
getarr
lib.manageevent
Name
Manage Event
File
manageevnet.py
Description
Routines for handling events.
Package Contents
- saveevent(event, filename, save=[‘event’], delete=[])
Saves an event in .dat (using cpickle) and .h5 (using h5py) files.
- loadevent(filename, load):
Loads an event stored in .dat and .h5 files.
- updateevent(event, filename, add):
Adds parameters given by add from filename to event.
Examples
>>> from manageevent import *
# Save hd209bs51_ini.dat and hd209bs51_ini.h5 files. >>> saveevent(event, ‘d209bs51_ini’,
save=[‘data’, ‘head’,’uncd’, ‘bdmskd’])
# Load the event and its data frames >>> event = loadevent(‘hd209bs51_ini’, [‘data’])
# Load uncd and bdmsk into event: >>> updateevent(event, ‘hd209bs51_ini’, [‘uncd’, ‘bdmskd’])
Revisions
- 2010-07-10 patricio joined loadevent and pcubillos@fulbrightmail.org
saveevent into this package. updateevent added.
2010-11-12 patricio reimplemented using exec()
- pacman.lib.manageevent.loadevent(filename: Path, load: Optional[List[str]] = [], loadfilename: Optional[bool] = None)[source]
Loads an event stored in .dat and .h5 files.
- Parameters:
- filenamepathlib.Path
Path to the event file.
- loadlist of str
The elements of this tuple contain the parameters to read. We usually use the values: ‘data’, ‘uncd’, ‘head’, ‘bdmskd’, ‘brmskd’ or ‘mask’.
- Returns:
- This function return an Event instance.
Notes
The input filename should not have the .dat nor the .h5 extentions.
Examples
See package example.
- pacman.lib.manageevent.saveevent(event, filename: Path, save: Optional[List[str]] = [], delete: Optional[List[str]] = [], protocol: Optional[int] = 3)[source]
Saves an event in .dat (using cpickle) and .h5 (using h5py) files.
- Parameters:
- event
An Event instance.
- filenamepathlib.Path
Path to the event file.
- savelist of str, optional
The elements of this tuple contain the parameters to save. We usually use the values: ‘data’, ‘uncd’, ‘head’, ‘bdmskd’, ‘brmksd’ or ‘mask’.
- deletelist of str, optional
Parameters to be deleted.
Notes
The input filename should not have the .dat nor the .h5 extentions. Side effect: This routine deletes all parameters except ‘event’ after saving it.
Examples
See package example.
- pacman.lib.manageevent.updateevent(event, filename: Path, add: List[str])[source]
Adds parameters given by add from filename to event.
- Parameters:
- eventAn Event instance.
- filenamepathlib.Path
Path to the event file.
- addlist of str
The elements of this tuple contain the parameters to add. We usually use the values: ‘data’, ‘uncd’, ‘head’, ‘bdmskd’, ‘brmaskd’ or ‘mask’.
- Returns:
- This function return an Event instance.
Notes
The input filename should not have the .dat nor the .h5 extentions.
Examples
See package example.
lib.update_meta
lib.suntimecorr
Author: carthik Revision: 267 Date: 2010-06-08 22:33:22 -0400 (Tue, 08 Jun 2010) HeadURL: file:///home/esp01/svn/code/python/branches/patricio/photpipe/lib/suntimecorr.py Id: suntimecorr.py 267 2010-06-09 02:33:22Z carthik
- pacman.lib.suntimecorr.getcoords(file)[source]
Use regular expressions to extract X,Y,Z, and time values from the horizons file.
- Parameters:
- fileStrings list
A list containing the lines of a horizons file.
- Returns:
- A four elements list containing the X, Y, Z, and time arrays of
- values from file.
- pacman.lib.suntimecorr.suntimecorr(meta, obst, coordtable: List[Path], verbose=False)[source]
This function calculates the light-travel time correction from observer to a standard location. It uses the 2D coordinates (RA and DEC) of the object being observed and the 3D position of the observer relative to the standard location. The latter (and the former, for solar-system objects) may be gotten from JPL’s Horizons system.
- Parameters:
- meta
includes ra, dec and other information
- obstfloat or numpy.ndarray
Time of observation in Julian Date (may be a vector)
- coordtablestr
Filename of output table from JPL HORIZONS specifying the position of the observatory relative to the standard position.
- verbosebool
If True, print X,Y,Z coordinates.
- Returns:
- This function returns the time correction in seconds to be ADDED
- to the observation time to get the time when the observed photons
- would have reached the plane perpendicular to their travel and
- containing the reference position.
Notes
The position vectors from coordtable are given in the following coordinate system: Reference epoch: J2000.0 xy-plane: plane of the Earth’s mean equator at the reference epoch x-axis : out along ascending node of instantaneous plane of the Earth’s
orbit and the Earth’s mean equator at the reference epoch
z-axis : along the Earth mean north pole at the reference epoch
Ephemerides are often calculated for BJD, barycentric Julian date. That is, they are correct for observations taken at the solar system barycenter’s distance from the target. The BJD of our observation is the time the photons we observe would have crossed the sphere centered on the object and containing the barycenter. We must thus add the light-travel time from our observatory to this sphere. For non-solar-system observations, we approximate the sphere as a plane, and calculate the dot product of the vector from the barycenter to the telescope and a unit vector to from the barycenter to the target, and divide by the speed of light.
Properly, the coordinates should point from the standard location to the object. Practically, for objects outside the solar system, the adjustment from, e.g., geocentric (RA-DEC) coordinates to barycentric coordinates has a negligible effect on the trig functions used in the routine.
The horizons file in coordtable should be in the form of the following example, with a subject line of JOB:
!$$SOF ! ! Example e-mail command file. If mailed to “horizons@ssd.jpl.nasa.gov” ! with subject “JOB”, results will be mailed back. ! ! This example demonstrates a subset of functions. See main doc for ! full explanation. Send blank e-mail with subject “BATCH-LONG” to ! horizons@ssd.jpl.nasa.gov for complete example. !
- EMAIL_ADDR = ‘shl35@cornell.edu’ ! Send output to this address
! (can be blank for auto-reply)
COMMAND = ‘-79’ ! Target body, closest apparition
OBJ_DATA = ‘YES’ ! No summary of target body data MAKE_EPHEM = ‘YES’ ! Make an ephemeris
START_TIME = ‘2005-Aug-24 06:00’ ! Start of table (UTC default) STOP_TIME = ‘2005-Aug-25 02:00’ ! End of table STEP_SIZE = ‘1 hour’ ! Table step-size
TABLE_TYPE = ‘VECTOR’ ! Specify VECTOR ephemeris table type CENTER = ‘@10’ ! Set observer (coordinate center) REF_PLANE = ‘FRAME’ ! J2000 equatorial plane
VECT_TABLE = ‘3’ ! Selects output type (3=all).
OUT_UNITS = ‘KM-S’ ! Vector units# KM-S, AU-D, KM-D CSV_FORMAT = ‘NO’ ! Comma-separated output (YES/NO) VEC_LABELS = ‘YES’ ! Label vectors in output (YES/NO) VECT_CORR = ‘NONE’ ! Correct for light-time (LT),
! or lt + stellar aberration (LT+S), ! or (NONE) return geometric ! vectors only.
!$$EOF
lib.plots
- pacman.lib.plots.badmask_2d(array1, array2, array3, meta, i)[source]
Plots the badmask arrays which are used by the optimal extraction routine.
- pacman.lib.plots.barycorr(x, y, z, time, obsx, obsy, obsz, coordtable: List[Path], meta)[source]
This function plots the vectorfile positions of HST and where the observations where taken
- Parameters:
- x: array
X position from vectorfile.
- y: array
Y position from vectorfile.
- z: array
Z position from vectorfile.
- time: array
times from the vectorfile.
- obsx: array
X position of observations.
- obsy: array
Y position of observations.
- obsz: array
Z position of observations.
- coordtablelist of pathlib.Path
a list of files containing the vector information of HST downloaded in s01.
- meta
the name of the metadata file.
- Returns:
- Saves and/or Shows a plot.
Notes
- History:
Written by Sebastian Zieba December 2021
- pacman.lib.plots.bkg_evo(bkg_evo, meta)[source]
Plot of the background flux as a function of up the ramp sample.
- pacman.lib.plots.bkg_hist(fullframe_diff, skymedian, meta, i, ii)[source]
Plot saving a histogram of the fluxes in the up-the-ramp sample. Showing the user decided background threshold and the median flux below the threshold.
- pacman.lib.plots.dyplot_traceplot(results, meta)[source]
Plot traces and 1-D marginalized posteriors.
- pacman.lib.plots.image(dat, ima, results, i, meta)[source]
This plots the full direct image with the guess of the target (defined using di_rmin, etc.) marked as a red box. It also plots a zoom into the guess position of the target with the gaussian fit solution marked with a cross.
- pacman.lib.plots.lsq_rprs(vals, errs, idxs, meta)[source]
Plots the spectrum (rprs vs wvl) as fitted by the least square routine.
- pacman.lib.plots.mcmc_chains(ndim, sampler, nburn, labels, meta)[source]
Plots the temporal evolution of the MCMC chain.
- pacman.lib.plots.mcmc_pairs(samples, params, meta, fit_par, data)[source]
Plots a pairs plot of the MCMC.
- pacman.lib.plots.mcmc_rprs(vals_mcmc, errs_lower_mcmc, errs_upper_mcmc, meta)[source]
Plots the spectrum (rprs vs wvl) as resulting from the MCMC.
- pacman.lib.plots.mjd_to_isot(time)[source]
Converts a list of MJDs to a list of dates in YYYY-MM-DD.
- pacman.lib.plots.nested_pairs(samples, params, meta, fit_par, data)[source]
Plots a pairs plot of the nested sampling.
- pacman.lib.plots.nested_rprs(vals_nested, errs_lower_nested, errs_upper_nested, meta)[source]
Plots the spectrum (rprs vs wvl) as resulting from the nested sampling.
- pacman.lib.plots.obs_times(meta, times, ivisits, iorbits, updated=False)[source]
Plot of the visit index as a function of observed time for the observations. Includes a table with the number of orbits in each visit and a zoom into each visit.
- Parameters:
- updatedbool
If the user decided to not use all visits but set some “which_visits” in the pcf, this bool is need to save a plot for all files in the data directory and a plot for the onces defined with “which_visits”. It prevents that when the function is being called again, the previous plot isnt overwritten.
- pacman.lib.plots.params_vs_wvl(vals, errs, idxs, meta)[source]
Plots every fitted parameter as a function of bin. It is able to show how astrophysical & systematical parameters change over wavelength.
- pacman.lib.plots.params_vs_wvl_mcmc(vals_mcmc, errs_lower_mcmc, errs_upper_mcmc, meta)[source]
Plots every fitted parameter as a function of bin. It is able to show how astrophysical & systematical parameters change over wavelength.
- pacman.lib.plots.params_vs_wvl_nested(vals_nested, errs_lower_nested, errs_upper_nested, meta)[source]
Plots every fitted parameter as a function of bin. It is able to show how astrophysical & systematical parameters change over wavelength.
- pacman.lib.plots.plot_fit_lc2(data, fit, meta, mcmc=False, nested=False)[source]
Plots phase folded fit.
- pacman.lib.plots.plot_fit_lc3(data, fit, meta, mcmc=False)[source]
Plots light curve without systematics model.
- pacman.lib.plots.plot_raw(data, meta)[source]
Saves a plot with the raw light curve (which includes the systematics).
- pacman.lib.plots.plot_wvl_bins(w_hires, f_interp, wave_bins, wvl_bins, dirname)[source]
Plot of a 1D spectrum and the bins.
- pacman.lib.plots.refspec(bp_wvl, bp_val, sm_wvl, sm_flux, ref_wvl, ref_flux, meta)[source]
Plots the bandpass, the stellar spectrum and the product of the both.
- pacman.lib.plots.rmsplot(model, data, meta, fitter=None)[source]
Plot RMS vs. bin size looking for time-correlated noise Taken from POET: https://github.com/kevin218/POET/blob/master/code/lib/plots.py.
- pacman.lib.plots.save_astrolc_data(data, fit, meta)[source]
Saves the data used to plot the astrophysical model (without the systematics) and the data (without the systematics) not phase folded.
- pacman.lib.plots.save_astrolc_data_nested(data, fit, meta)[source]
Saves the data used to plot the astrophysical model (without the systematics) and the data (without the systematics) not phase folded.
- pacman.lib.plots.save_plot_raw_data(data, meta)[source]
Saves the data used for the raw light curve plot.
- pacman.lib.plots.smooth(meta, x, y, x_smoothed, y_smoothed)[source]
Plots the raw stellar spectrum and the smoothed spectrum.
- pacman.lib.plots.sp1d(template_waves, spec_box, meta, i, spec_opt=False)[source]
Plots the resulting spectrum. If the user did optimal extraction, a comparison between optextr and box sum will be shown.
- pacman.lib.plots.sp1d_diff(sp1d_all_diff, meta, wvl_hires)[source]
Difference of 1D spectrum between two consecutive exposures.
- pacman.lib.plots.sp2d(d, meta, i)[source]
Plot the spectrum with a low vmax to make the background better visible.
- pacman.lib.plots.trace(d, meta, visnum, orbnum, i)[source]
Plots the spectrum together with the trace.
lib.stellar_spectrum
- pacman.lib.stellar_spectrum.downloader(url: str) None [source]
This function downloads a file from the given url using urllib.request.
- pacman.lib.stellar_spectrum.find_nearest(array: Union[Sequence[Sequence[Sequence[Sequence[Sequence[Any]]]]], _SupportsArray[dtype], Sequence[_SupportsArray[dtype]], Sequence[Sequence[_SupportsArray[dtype]]], Sequence[Sequence[Sequence[_SupportsArray[dtype]]]], Sequence[Sequence[Sequence[Sequence[_SupportsArray[dtype]]]]], bool, int, float, complex, str, bytes, Sequence[Union[bool, int, float, complex, str, bytes]], Sequence[Sequence[Union[bool, int, float, complex, str, bytes]]], Sequence[Sequence[Sequence[Union[bool, int, float, complex, str, bytes]]]], Sequence[Sequence[Sequence[Sequence[Union[bool, int, float, complex, str, bytes]]]]]], value: float)[source]
Finds nearest element to a value in an array.
Taken from https://stackoverflow.com/questions/2566412/find-nearest-value-in-numpy-array
- pacman.lib.stellar_spectrum.get_bb(user_teff)[source]
Creates a blackbody spectrum for a given stellar effective temperature, Teff.
- Parameters:
- user_teff: float
stellar effective temperature
- Returns:
- wvl: numpy array
wavelength np.linspace(0.1, 6, 1000) / 1e6
- flux: numpy array
stellar flux in units of W/sr/m^3
- pacman.lib.stellar_spectrum.get_sm(meta, user_met, user_logg: float, user_teff: float)[source]
Creates a Kurucz 1994, Castelli and Kurucz 2004 or Phoenix stellar spectrum for a given stellar effective temperature, metallicity and log g.
- Parameters:
- meta
a metadata instance.
- user_metfloat
stellar metallicity.
- user_loggfloat
stellar logg.
- user_tefffloat
stellar effective temperature.
- Returns:
- wvlnumpy array
wavelength np.linspace(0.1, 6, 1000) / 1e6.
- fluxnumpy array
stellar flux in units of W/sr/m^3.
lib.gaussfitter
Latest version available at <http://code.google.com/p/agpy/source/browse/trunk/agpy/gaussfitter.py>
Note about mpfit/leastsq: I switched everything over to the Markwardt mpfit routine for a few reasons, but foremost being the ability to set limits on parameters, not just force them to be fixed. As far as I can tell, leastsq does not have that capability.
- The version of mpfit I use can be found here:
- pacman.lib.gaussfitter.collapse_gaussfit(cube, xax=None, axis=2, negamp=False, usemoments=True, nsigcut=1.0, mppsigcut=1.0, return_errors=False, **kwargs)[source]
- pacman.lib.gaussfitter.gaussfit(data, err=None, params=(), autoderiv=True, return_all=False, circle=False, fixed=array([False, False, False, False, False, False, False]), limitedmin=[False, False, False, False, True, True, True], limitedmax=[False, False, False, False, False, False, True], usemoment=array([], dtype=bool), minpars=array([0, 0, 0, 0, 0, 0, 0]), maxpars=[0, 0, 0, 0, 0, 0, 360], rotate=1, vheight=1, quiet=True, returnmp=False, returnfitimage=False, **kwargs)[source]
Gaussian fitter with the ability to fit a variety of different forms of 2-dimensional gaussian.
- Input Parameters:
data - 2-dimensional data array err=None - error array with same size as data array params=[] - initial input parameters for Gaussian function.
(height, amplitude, x, y, width_x, width_y, rota) if not input, these will be determined from the moments of the system, assuming no rotation
- autoderiv=1 - use the autoderiv provided in the lmder.f function (the
alternative is to us an analytic derivative with lmdif.f: this method is less robust)
- return_all=0 - Default is to return only the Gaussian parameters.
1 - fit params, fit error
returnfitimage - returns (best fit params,best fit image) returnmp - returns the full mpfit struct circle=0 - default is an elliptical gaussian (different x, y widths),
but can reduce the input by one parameter if it’s a circular gaussian
- rotate=1 - default allows rotation of the gaussian ellipse. Can remove
last parameter by setting rotate=0. numpy.expects angle in DEGREES
- vheight=1 - default allows a variable height-above-zero, i.e. an
additive constant for the Gaussian function. Can remove first parameter by setting this to 0
- usemoment - can choose which parameters to use a moment estimation for.
Other parameters will be taken from params. Needs to be a boolean array.
- Output:
- Default output is a set of Gaussian parameters with the same shape as
the input parameters
- Can also output the covariance matrix, ‘infodict’ that contains a lot
more detail about the fit (see scipy.optimize.leastsq), and a message from leastsq telling what the exit status of the fitting routine was
Warning: Does NOT necessarily output a rotation angle between 0 and 360 degrees.
- pacman.lib.gaussfitter.moments(data, circle, rotate, vheight, estimator=<function median>, **kwargs)[source]
Returns (height, amplitude, x, y, width_x, width_y, rotation angle) the gaussian parameters of a 2D distribution by calculating its moments. Depending on the input parameters, will only output a subset of the above.
If using masked arrays, pass estimator=numpy.ma.median.
- pacman.lib.gaussfitter.multigaussfit(xax, data, ngauss=1, err=None, params=[1, 0, 1], fixed=[False, False, False], limitedmin=[False, False, True], limitedmax=[False, False, False], minpars=[0, 0, 0], maxpars=[0, 0, 0], quiet=True, shh=True, veryverbose=False)[source]
An improvement on onedgaussfit. Lets you fit multiple gaussians.
- Inputs:
xax - x axis data - y axis ngauss - How many gaussians to fit? Default 1 (this could supersede onedgaussfit) err - error corresponding to data
These parameters need to have length = 3*ngauss. If ngauss > 1 and length = 3, they will be replicated ngauss times, otherwise they will be reset to defaults:
- params - Fit parameters: [amplitude, offset, width] * ngauss
If len(params) % 3 == 0, ngauss will be set to len(params) / 3
fixed - Is parameter fixed? limitedmin/minpars - set lower limits on each parameter (default: width>0) limitedmax/maxpars - set upper limits on each parameter
quiet - should MPFIT output each iteration? shh - output final parameters?
- Returns:
Fit parameters Model Fit errors chi2
- pacman.lib.gaussfitter.n_gaussian(pars=None, a=None, dx=None, sigma=None)[source]
Returns a function that sums over N gaussians, where N is the length of a,dx,sigma OR N = len(pars) / 3
The background “height” is assumed to be zero (you must “baseline” your spectrum before fitting)
pars - a list with len(pars) = 3n, assuming a,dx,sigma repeated dx - offset (velocity center) values sigma - line widths a - amplitudes
- pacman.lib.gaussfitter.onedgaussfit(xax, data, err=None, params=[0, 1, 0, 1], fixed=[False, False, False, False], limitedmin=[False, False, False, True], limitedmax=[False, False, False, False], minpars=[0, 0, 0, 0], maxpars=[0, 0, 0, 0], quiet=True, shh=True, veryverbose=False, vheight=True, negamp=False, usemoments=False)[source]
- Inputs:
xax - x axis data - y axis err - error corresponding to data
params - Fit parameters: Height of background, Amplitude, Shift, Width fixed - Is parameter fixed? limitedmin/minpars - set lower limits on each parameter (default: width>0) limitedmax/maxpars - set upper limits on each parameter quiet - should MPFIT output each iteration? shh - output final parameters? usemoments - replace default parameters with moments
- Returns:
Fit parameters Model Fit errors chi2
- pacman.lib.gaussfitter.onedgaussian(x, H, A, dx, w)[source]
Returns a 1-dimensional gaussian of form H+A*numpy.exp(-(x-dx)**2/(2*w**2))
- pacman.lib.gaussfitter.onedmoments(Xax, data, vheight=True, estimator=<function median>, negamp=None, veryverbose=False, **kwargs)[source]
Returns (height, amplitude, x, width_x) the gaussian parameters of a 1D distribution by calculating its moments. Depending on the input parameters, will only output a subset of the above.
If using masked arrays, pass estimator=numpy.ma.median ‘estimator’ is used to measure the background level (height)
negamp can be used to force the peak negative (True), positive (False), or it will be “autodetected” (negamp=None)
- pacman.lib.gaussfitter.twodgaussian(inpars, circle=False, rotate=True, vheight=True, shape=None)[source]
Returns a 2d gaussian function of the form: x’ = numpy.cos(rota) * x - numpy.sin(rota) * y y’ = numpy.sin(rota) * x + numpy.cos(rota) * y (rota should be in degrees) g = b + a * numpy.exp ( - ( ((x-center_x)/width_x)**2 + ((y-center_y)/width_y)**2 ) / 2 )
- inpars = [b,a,center_x,center_y,width_x,width_y,rota]
(b is background height, a is peak amplitude)
where x and y are the input parameters of the returned function, and all other parameters are specified by this function
However, the above values are passed by list. The list should be: inpars = (height,amplitude,center_x,center_y,width_x,width_y,rota)
- You can choose to ignore / neglect some of the above input parameters
unumpy.sing the following options: circle=0 - default is an elliptical gaussian (different x, y
widths), but can reduce the input by one parameter if it’s a circular gaussian
- rotate=1 - default allows rotation of the gaussian ellipse. Can
remove last parameter by setting rotate=0
- vheight=1 - default allows a variable height-above-zero, i.e. an
additive constant for the Gaussian function. Can remove first parameter by setting this to 0
- shape=None - if shape is set (to a 2-parameter list) then returns
an image with the gaussian defined by inpars
lib.mpfit
Perform Levenberg-Marquardt least-squares minimization, based on MINPACK-1.
AUTHORS
The original version of this software, called LMFIT, was written in FORTRAN as part of the MINPACK-1 package by XXX.
Craig Markwardt converted the FORTRAN code to IDL. The information for the IDL version is:
Craig B. Markwardt, NASA/GSFC Code 662, Greenbelt, MD 20770
craigm@lheamail.gsfc.nasa.gov UPDATED VERSIONs can be found on my WEB PAGE:
- Mark Rivers created this Python version from Craig’s IDL version.
Mark Rivers, University of Chicago Building 434A, Argonne National Laboratory 9700 South Cass Avenue, Argonne, IL 60439 rivers@cars.uchicago.edu Updated versions can be found at http://cars.uchicago.edu/software
- Sergey Koposov converted the Mark’s Python version from Numeric to numpy
Sergey Koposov, University of Cambridge, Institute of Astronomy, Madingley road, CB3 0HA, Cambridge, UK koposov@ast.cam.ac.uk Updated versions can be found at http://code.google.com/p/astrolibpy/source/browse/trunk/
DESCRIPTION
MPFIT uses the Levenberg-Marquardt technique to solve the least-squares problem. In its typical use, MPFIT will be used to fit a user-supplied function (the “model”) to user-supplied data points (the “data”) by adjusting a set of parameters. MPFIT is based upon MINPACK-1 (LMDIF.F) by More’ and collaborators.
For example, a researcher may think that a set of observed data points is best modelled with a Gaussian curve. A Gaussian curve is parameterized by its mean, standard deviation and normalization. MPFIT will, within certain constraints, find the set of parameters which best fits the data. The fit is “best” in the least-squares sense; that is, the sum of the weighted squared differences between the model and data is minimized.
The Levenberg-Marquardt technique is a particular strategy for iteratively searching for the best fit. This particular implementation is drawn from MINPACK-1 (see NETLIB), and is much faster and more accurate than the version provided in the Scientific Python package in Scientific.Functions.LeastSquares. This version allows upper and lower bounding constraints to be placed on each parameter, or the parameter can be held fixed.
The user-supplied Python function should return an array of weighted deviations between model and data. In a typical scientific problem the residuals should be weighted so that each deviate has a gaussian sigma of 1.0. If X represents values of the independent variable, Y represents a measurement for each value of X, and ERR represents the error in the measurements, then the deviates could be calculated as follows:
DEVIATES = (Y - F(X)) / ERR
where F is the analytical function representing the model. You are recommended to use the convenience functions MPFITFUN and MPFITEXPR, which are driver functions that calculate the deviates for you. If ERR are the 1-sigma uncertainties in Y, then
TOTAL( DEVIATES^2 )
will be the total chi-squared value. MPFIT will minimize the chi-square value. The values of X, Y and ERR are passed through MPFIT to the user-supplied function via the FUNCTKW keyword.
Simple constraints can be placed on parameter values by using the PARINFO keyword to MPFIT. See below for a description of this keyword.
MPFIT does not perform more general optimization tasks. See TNMIN instead. MPFIT is customized, based on MINPACK-1, to the least-squares minimization problem.
USER FUNCTION
The user must define a function which returns the appropriate values as specified above. The function should return the weighted deviations between the model and the data. It should also return a status flag and an optional partial derivative array. For applications which use finite-difference derivatives – the default – the user function should be declared in the following way:
def myfunct(p, fjac=None, x=None, y=None, err=None)
# Parameter values are passed in “p” # If fjac==None then partial derivatives should not be # computed. It will always be None if MPFIT is called with default # flag. model = F(x, p) # Non-negative status value means MPFIT should continue, negative means # stop the calculation. status = 0 return([status, (y-model)/err]
See below for applications with analytical derivatives.
The keyword parameters X, Y, and ERR in the example above are suggestive but not required. Any parameters can be passed to MYFUNCT by using the functkw keyword to MPFIT. Use MPFITFUN and MPFITEXPR if you need ideas on how to do that. The function must accept a parameter list, P.
In general there are no restrictions on the number of dimensions in X, Y or ERR. However the deviates must be returned in a one-dimensional Numeric array of type Float.
User functions may also indicate a fatal error condition using the status return described above. If status is set to a number between -15 and -1 then MPFIT will stop the calculation and return to the caller.
ANALYTIC DERIVATIVES
In the search for the best-fit solution, MPFIT by default calculates derivatives numerically via a finite difference approximation. The user-supplied function need not calculate the derivatives explicitly. However, if you desire to compute them analytically, then the AUTODERIVATIVE=0 keyword must be passed to MPFIT. As a practical matter, it is often sufficient and even faster to allow MPFIT to calculate the derivatives numerically, and so AUTODERIVATIVE=0 is not necessary.
If AUTODERIVATIVE=0 is used then the user function must check the parameter FJAC, and if FJAC!=None then return the partial derivative array in the return list. def myfunct(p, fjac=None, x=None, y=None, err=None) # Parameter values are passed in “p” # If FJAC!=None then partial derivatives must be comptuer. # FJAC contains an array of len(p), where each entry # is 1 if that parameter is free and 0 if it is fixed. model = F(x, p) Non-negative status value means MPFIT should continue, negative means # stop the calculation. status = 0 if (dojac): pderiv = zeros([len(x), len(p)], Float) for j in range(len(p)): pderiv[:,j] = FGRAD(x, p, j) else: pderiv = None return([status, (y-model)/err, pderiv]
where FGRAD(x, p, i) is a user function which must compute the derivative of the model with respect to parameter P[i] at X. When finite differencing is used for computing derivatives (ie, when
AUTODERIVATIVE=1), or when MPFIT needs only the errors but not the
derivatives the parameter FJAC=None.
Derivatives should be returned in the PDERIV array. PDERIV should be an m x n array, where m is the number of data points and n is the number of parameters. dp[i,j] is the derivative at the ith point with respect to the jth parameter.
The derivatives with respect to fixed parameters are ignored; zero is an appropriate value to insert for those derivatives. Upon input to the user function, FJAC is set to a vector with the same length as P, with a value of 1 for a parameter which is free, and a value of zero for a parameter which is fixed (and hence no
derivative needs to be calculated).
If the data is higher than one dimensional, then the last dimension should be the parameter dimension. Example: fitting a 50x50 image, “dp” should be 50x50xNPAR.
CONSTRAINING PARAMETER VALUES WITH THE PARINFO KEYWORD
The behavior of MPFIT can be modified with respect to each parameter to be fitted. A parameter value can be fixed; simple boundary constraints can be imposed; limitations on the parameter changes can be imposed; properties of the automatic derivative can be modified; and parameters can be tied to one another.
These properties are governed by the PARINFO structure, which is passed as a keyword parameter to MPFIT.
PARINFO should be a list of dictionaries, one list entry for each parameter. Each parameter is associated with one element of the array, in numerical order. The dictionary can have the following keys (none are required, keys are case insensitive):
- ‘value’ - the starting parameter value (but see the START_PARAMS
parameter for more information).
‘fixed’ - a boolean value, whether the parameter is to be held fixed or not. Fixed parameters are not varied by MPFIT, but are passed on to MYFUNCT for evaluation.
‘limited’ - a two-element boolean array. If the first/second element is set, then the parameter is bounded on the lower/upper side. A parameter can be bounded on both
- sides. Both LIMITED and LIMITS must be given
together.
- ‘limits’ - a two-element float array. Gives the
parameter limits on the lower and upper sides, respectively. Zero, one or two of these values can be set, depending on the values of LIMITED. Both LIMITED and LIMITS must be given together.
- ‘parname’ - a string, giving the name of the parameter. The
fitting code of MPFIT does not use this tag in any way. However, the default iterfunct will print the parameter name if available.
- ‘step’ - the step size to be used in calculating the numerical
derivatives. If set to zero, then the step size is computed automatically. Ignored when AUTODERIVATIVE=0.
- ‘mpside’ - the sidedness of the finite difference when computing
numerical derivatives. This field can take four values:
0 - one-sided derivative computed automatically
1 - one-sided derivative (f(x+h) - f(x) )/h
- -1 - one-sided derivative (f(x) - f(x-h))/h
2 - two-sided derivative (f(x+h) - f(x-h))/(2*h)
Where H is the STEP parameter described above. The “automatic” one-sided derivative method will chose a direction for the finite difference which does not violate any constraints. The other methods do not perform this check. The two-sided method is in principle more precise, but requires twice as many function evaluations. Default: 0.
- ‘mpmaxstep’ - the maximum change to be made in the parameter
value. During the fitting process, the parameter will never be changed by more than this value in one iteration.
A value of 0 indicates no maximum. Default: 0.
- ‘tied’ - a string expression which “ties” the parameter to other
free or fixed parameters. Any expression involving constants and the parameter array P are permitted. Example: if parameter 2 is always to be twice parameter 1 then use the following: parinfo(2).tied = ‘2 * p(1)’. Since they are totally constrained, tied parameters are considered to be fixed; no errors are computed for them. [ NOTE: the PARNAME can’t be used in expressions. ]
- ‘mpprint’ - if set to 1, then the default iterfunct will print the
parameter value. If set to 0, the parameter value will not be printed. This tag can be used to selectively print only a few parameter values out of many. Default: 1 (all parameters printed)
Future modifications to the PARINFO structure, if any, will involve adding dictionary tags beginning with the two letters “MP”. Therefore programmers are urged to avoid using tags starting with the same letters; otherwise they are free to include their own fields within the PARINFO structure, and they will be ignored.
- PARINFO Example:
- parinfo = [{‘value’:0., ‘fixed’:0, ‘limited’:[0,0], ‘limits’:[0.,0.]}
for i in range(5)]
parinfo[0][‘fixed’] = 1 parinfo[4][‘limited’][0] = 1 parinfo[4][‘limits’][0] = 50. values = [5.7, 2.2, 500., 1.5, 2000.] for i in range(5): parinfo[i][‘value’]=values[i]
A total of 5 parameters, with starting values of 5.7, 2.2, 500, 1.5, and 2000 are given. The first parameter is fixed at a value of 5.7, and the last parameter is constrained to be above 50.
EXAMPLE
import mpfit import numpy.oldnumeric as Numeric x = arange(100, float) p0 = [5.7, 2.2, 500., 1.5, 2000.] y = ( p[0] + p[1]*[x] + p[2]*[x**2] + p[3]*sqrt(x) +
p[4]*log(x))
fa = {‘x’:x, ‘y’:y, ‘err’:err} m = mpfit(‘myfunct’, p0, functkw=fa) print ‘status = ‘, m.status if (m.status <= 0): print ‘error message = ‘, m.errmsg print ‘parameters = ‘, m.params
Minimizes sum of squares of MYFUNCT. MYFUNCT is called with the X, Y, and ERR keyword parameters that are given by FUNCTKW. The results can be obtained from the returned object m.
THEORY OF OPERATION
There are many specific strategies for function minimization. One very popular technique is to use function gradient information to realize the local structure of the function. Near a local minimum the function value can be taylor expanded about x0 as follows:
- f(x) = f(x0) + f’(x0) . (x-x0) + (1/2) (x-x0) . f’’(x0) . (x-x0)
—– ————— ——————————- (1)
Order 0th 1st 2nd
Here f’(x) is the gradient vector of f at x, and f’’(x) is the Hessian matrix of second derivatives of f at x. The vector x is the set of function parameters, not the measured data vector. One can find the minimum of f, f(xm) using Newton’s method, and arrives at the following linear equation:
f’’(x0) . (xm-x0) = - f’(x0) (2)
If an inverse can be found for f’’(x0) then one can solve for (xm-x0), the step vector from the current position x0 to the new projected minimum. Here the problem has been linearized (ie, the
gradient information is known to first order). f’’(x0) is
symmetric n x n matrix, and should be positive definite.
The Levenberg - Marquardt technique is a variation on this theme. It adds an additional diagonal term to the equation which may aid the convergence properties:
(f’’(x0) + nu I) . (xm-x0) = -f’(x0) (2a)
where I is the identity matrix. When nu is large, the overall matrix is diagonally dominant, and the iterations follow steepest descent. When nu is small, the iterations are quadratically convergent.
In principle, if f’’(x0) and f’(x0) are known then xm-x0 can be determined. However the Hessian matrix is often difficult or impossible to compute. The gradient f’(x0) may be easier to compute, if even by finite difference techniques. So-called quasi-Newton techniques attempt to successively estimate f’’(x0) by building up gradient information as the iterations proceed.
In the least squares problem there are further simplifications which assist in solving eqn (2). The function to be minimized is a sum of squares:
f = Sum(hi^2) (3)
where hi is the ith residual out of m residuals as described above. This can be substituted back into eqn (2) after computing the derivatives:
f’ = 2 Sum(hi hi’) f’’ = 2 Sum(hi’ hj’) + 2 Sum(hi hi’’) (4)
If one assumes that the parameters are already close enough to a minimum, then one typically finds that the second term in f’’ is negligible [or, in any case, is too difficult to compute]. Thus, equation (2) can be solved, at least approximately, using only gradient information.
In matrix notation, the combination of eqns (2) and (4) becomes:
hT’ . h’ . dx = - hT’ . h (5)
Where h is the residual vector (length m), hT is its transpose, h’ is the Jacobian matrix (dimensions n x m), and dx is (xm-x0). The user function supplies the residual vector h, and in some cases h’ when it is not found by finite differences (see MPFIT_FDJAC2,
which finds h and hT’). Even if dx is not the best absolute step
to take, it does provide a good estimate of the best direction, so often a line minimization will occur along the dx vector direction.
The method of solution employed by MINPACK is to form the Q . R factorization of h’, where Q is an orthogonal matrix such that QT . Q = I, and R is upper right triangular. Using h’ = Q . R and the ortogonality of Q, eqn (5) becomes
- (RT . QT) . (Q . R) . dx = - (RT . QT) . h
- RT . R . dx = - RT . QT . h (6)
R . dx = - QT . h
where the last statement follows because R is upper triangular. Here, R, QT and h are known so this is a matter of solving for dx. The routine MPFIT_QRFAC provides the QR factorization of h, with pivoting, and MPFIT_QRSOLV provides the solution for dx.
REFERENCES
MINPACK-1, Jorge More’, available from netlib (www.netlib.org). “Optimization Software Guide,” Jorge More’ and Stephen Wright,
SIAM, Frontiers in Applied Mathematics, Number 14.
- More’, Jorge J., “The Levenberg-Marquardt Algorithm:
Implementation and Theory,” in Numerical Analysis, ed. Watson,
A., Lecture Notes in Mathematics 630, Springer-Verlag, 1977.
MODIFICATION HISTORY
Translated from MINPACK-1 in FORTRAN, Apr-Jul 1998, CM
Copyright (C) 1997-2002, Craig Markwardt This software is provided as is without any warranty whatsoever. Permission to use, copy, modify, and distribute modified or unmodified copies is granted, provided this copyright and disclaimer are included unchanged.
Translated from MPFIT (Craig Markwardt’s IDL package) to Python, August, 2002. Mark Rivers Converted from Numeric to numpy (Sergey Koposov, July 2008)
- class pacman.lib.mpfit.mpfit(fcn, xall=None, functkw={}, parinfo=None, ftol=1e-10, xtol=1e-10, gtol=1e-10, damp=0.0, maxiter=200, factor=100.0, nprint=1, iterfunct='default', iterkw={}, nocovar=0, rescale=0, autoderivative=1, quiet=0, diag=None, epsfcn=None, debug=0)[source]
Bases:
object
Methods
blas_enorm32
(x,[n,offx,incx])blas_enorm64
(x,[n,offx,incx])call
(fcn, x, functkw[, fjac])defiter
(fcn, x, iter[, fnorm, functkw, ...])parinfo
([parinfo, key, default, n])tie
(p[, ptied])calc_covar
enorm
fdjac2
lmpar
qrfac
qrsolv
- blas_enorm32(x[, n, offx, incx]) = <fortran dnrm2>
- blas_enorm64(x[, n, offx, incx]) = <fortran dnrm2>
- defiter(fcn, x, iter, fnorm=None, functkw=None, quiet=0, iterstop=None, parinfo=None, format=None, pformat='%.10g', dof=1)[source]
lib.geometry102
- pacman.lib.geometry102.dispersion(X_ref, Y_ref)[source]
Calculates coefficients for the dispersion solution See also: https://ui.adsabs.harvard.edu/abs/2009wfc..rept…18K/abstract
- Parameters:
- eventlabelX_ref and Y_ref
centroid position in physical pixels
- pacman.lib.geometry102.trace(X_ref, Y_ref)[source]
Calculates the slope and intercept for the trace, given the position of the direct image in physical pixels. These coefficients are for the WFC3 G102 grism. See also: https://ui.adsabs.harvard.edu/abs/2009wfc..rept…18K/abstract
lib.geometry141
- pacman.lib.geometry141.dispersion(X_ref, Y_ref)[source]
Calculates coefficients for the dispersion solution See also: https://ui.adsabs.harvard.edu/abs/2009wfc..rept…17K/abstract
- Parameters:
- eventlabelX_ref and Y_ref
centroid position in physical pixels
- pacman.lib.geometry141.trace(X_ref, Y_ref)[source]
Calculates the slope and intercept for the trace, given the position of the direct image in physical pixels. These coefficients are for the WFC3 G141 grism. See also: https://ui.adsabs.harvard.edu/abs/2009wfc..rept…17K/abstract
lib.optextr
- pacman.lib.optextr.diagnostics_plot(D, M, indmax, outlier_array, f_opt, profile, i, ii, meta)[source]
- pacman.lib.optextr.optextr(D, err, f_std, var_std, M, nsmooth, sig_cut, save_optextr_plot, i_sp, ii_sp, meta)[source]
Function to optimally extract a spectrum.
- Parameters:
- D:
data array (already background subtracted)
- err:
error array (in addition to photon noise; e.g. error due to background subtraction)
- f_std:
box-extracted spectrum (from step 4 of Horne)
- var_std:
variance of standard spectrum (also from step 4)
- M:
array masking bad pixels; 0 is bad and 1 is good
- nsmooth:
number of pixels to smooth over to estimate the spatial profile (7 works well)
- sig_cut:
cutoff sigma for flagging outliers (10.0 works well)
- diagnostics:
boolean flag specifying whether to make diagnostic plots
- Returns:
- f_opt, var_opt:
optimally extracted spectrum and its variance
lib.sort_nicely
- pacman.lib.sort_nicely.alphanum_key(string: str) str [source]
Turn a string into a list of string and number chunks. “z23a” -> [“z”, 23, “a”].
lib.read_fit_par
lib.read_data
- class pacman.lib.read_data.Data(data_file, meta, fit_par, clip_idx=[])[source]
Bases:
object
Reads in and stores raw light curve data :param data_file: :param obs_par: :param fit_par:
lib.model
lib.least_squares
lib.mcmc
lib.models
lib.models.constant
lib.models.constants_cj
- pacman.lib.models.constants_cj.constants_cj(t, data, params, visit=0)[source]
Example
In [47]: iexp_orb_sp = np.array([0,1,2,3,0,1,2,3,4])
In [48]: Cs = np.array([[7.8], [8.3], [8.5], [8.6], [8.65]])
In [49]: C_data_mask = [iexp_orb_sp == i for i in range(max(iexp_orb_sp)+1)]
In [50]: C_data_mask Out[50]: [array([ True, False, False, False, True, False, False, False, False]),
array([False, True, False, False, False, True, False, False, False]), array([False, False, True, False, False, False, True, False, False]), array([False, False, False, True, False, False, False, True, False]), array([False, False, False, False, False, False, False, False, True])]
In [51]: C_data_mask*Cs Out[51]: array([[7.8 , 0. , 0. , 0. , 7.8 , 0. , 0. , 0. , 0. ],
[0. , 8.3 , 0. , 0. , 0. , 8.3 , 0. , 0. , 0. ], [0. , 0. , 8.5 , 0. , 0. , 0. , 8.5 , 0. , 0. ], [0. , 0. , 0. , 8.6 , 0. , 0. , 0. , 8.6 , 0. ], [0. , 0. , 0. , 0. , 0. , 0. , 0. , 0. , 8.65]])
In [52]: np.sum(C_data_mask*Cs, axis=0) Out[52]: array([7.8 , 8.3 , 8.5 , 8.6 , 7.8 , 8.3 , 8.5 , 8.6 , 8.65])