Reference/API

Capabilities

astropy.modeling Package

This subpackage provides a framework for representing models and performing model evaluation and fitting. It supports 1D and 2D models and fitting with parameter constraints. It has some predefined models and fitting routines.

Functions

custom_model(\*args[, fit_deriv])

Create a model from a user defined function.

fix_inputs(modelinstance, values)

This function creates a compound model with one or more of the input values of the input model assigned fixed values (scalar or array).

is_separable(transform)

A separability test for the outputs of a transform.

separability_matrix(transform)

Compute the correlation between outputs and inputs.

Classes

CompoundModel(op, left, right[, name, inverse])

Base class for compound models.

Fittable1DModel(*args[, meta, name])

Base class for one-dimensional fittable models.

Fittable2DModel(*args[, meta, name])

Base class for two-dimensional fittable models.

FittableModel(*args[, meta, name])

Base class for models that can be fitted using the built-in fitting algorithms.

InputParameterError

Used for incorrect input parameter values and definitions.

Model(*args[, meta, name])

Base class for all models.

ModelDefinitionError

Used for incorrect models definitions.

Parameter([name, description, default, …])

Wraps individual parameters.

ParameterError

Generic exception class for all exceptions pertaining to Parameters.

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.core.CompoundModel, astropy.modeling.core.Fittable1DModel, astropy.modeling.core.Fittable2DModel, astropy.modeling.core.FittableModel, astropy.modeling.parameters.InputParameterError, astropy.modeling.core.Model, astropy.modeling.core.ModelDefinitionError, astropy.modeling.parameters.Parameter, astropy.modeling.parameters.ParameterError

astropy.modeling.mappings Module

Special models useful for complex compound models where control is needed over which outputs from a source model are mapped to which inputs of a target model.

Classes

Mapping(mapping[, n_inputs, name, meta])

Allows inputs to be reordered, duplicated or dropped.

Identity(n_inputs[, name, meta])

Returns inputs unchanged.

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.mappings.Mapping, astropy.modeling.mappings.Identity

astropy.modeling.fitting Module

This module implements classes (called Fitters) which combine optimization algorithms (typically from scipy.optimize) with statistic functions to perform fitting. Fitters are implemented as callable classes. In addition to the data to fit, the __call__ method takes an instance of FittableModel as input, and returns a copy of the model with its parameters determined by the optimizer.

Optimization algorithms, called “optimizers” are implemented in optimizers and statistic functions are in statistic. The goal is to provide an easy to extend framework and allow users to easily create new fitters by combining statistics with optimizers.

There are two exceptions to the above scheme. LinearLSQFitter uses Numpy’s lstsq function. LevMarLSQFitter uses leastsq which combines optimization and statistic in one implementation.

Classes

LinearLSQFitter()

A class performing a linear least square fitting.

LevMarLSQFitter()

Levenberg-Marquardt algorithm and least squares statistic.

FittingWithOutlierRemoval(fitter, outlier_func)

This class combines an outlier removal technique with a fitting procedure.

SLSQPLSQFitter()

SLSQP optimization algorithm and least squares statistic.

SimplexLSQFitter()

Simplex algorithm and least squares statistic.

JointFitter(models, jointparameters, initvals)

Fit models which share a parameter.

Fitter(optimizer, statistic)

Base class for all fitters.

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.fitting.LinearLSQFitter, astropy.modeling.fitting.LevMarLSQFitter, astropy.modeling.fitting.FittingWithOutlierRemoval, astropy.modeling.fitting.SLSQPLSQFitter, astropy.modeling.fitting.SimplexLSQFitter, astropy.modeling.fitting.JointFitter, astropy.modeling.fitting.Fitter

astropy.modeling.optimizers Module

Optimization algorithms used in fitting.

Classes

Optimization(opt_method)

Base class for optimizers.

SLSQP()

Sequential Least Squares Programming optimization algorithm.

Simplex()

Neald-Mead (downhill simplex) algorithm.

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.optimizers.Optimization, astropy.modeling.optimizers.SLSQP, astropy.modeling.optimizers.Simplex

astropy.modeling.statistic Module

Statistic functions used in fitting.

Functions

leastsquare(measured_vals, updated_model, …)

Least square statistic with optional weights.

astropy.modeling.tabular Module

Tabular models.

Tabular models of any dimension can be created using tabular_model. For convenience Tabular1D and Tabular2D are provided.

Examples

>>> table = np.array([[ 3.,  0.,  0.],
...                  [ 0.,  2.,  0.],
...                  [ 0.,  0.,  0.]])
>>> points = ([1, 2, 3], [1, 2, 3])
>>> t2 = Tabular2D(points, lookup_table=table, bounds_error=False,
...                fill_value=None, method='nearest')

Functions

tabular_model(dim[, name])

Make a Tabular model where n_inputs is based on the dimension of the lookup_table.

astropy.modeling.separable Module

Functions to determine if a model is separable, i.e. if the model outputs are independent.

It analyzes n_inputs, n_outputs and the operators in a compound model by stepping through the transforms and creating a coord_matrix of shape (n_outputs, n_inputs).

Each modeling operator is represented by a function which takes two simple models (or two coord_matrix arrays) and returns an array of shape (n_outputs, n_inputs).

Functions

is_separable(transform)

A separability test for the outputs of a transform.

separability_matrix(transform)

Compute the correlation between outputs and inputs.

Pre-Defined Models

astropy.modeling.functional_models Module

Mathematical models.

Classes

AiryDisk2D([amplitude, x_0, y_0, radius])

Two dimensional Airy disk model.

Moffat1D([amplitude, x_0, gamma, alpha])

One dimensional Moffat model.

Moffat2D([amplitude, x_0, y_0, gamma, alpha])

Two dimensional Moffat model.

Box1D([amplitude, x_0, width])

One dimensional Box model.

Box2D([amplitude, x_0, y_0, x_width, y_width])

Two dimensional Box model.

Const1D([amplitude])

One dimensional Constant model.

Const2D([amplitude])

Two dimensional Constant model.

Ellipse2D([amplitude, x_0, y_0, a, b, theta])

A 2D Ellipse model.

Disk2D([amplitude, x_0, y_0, R_0])

Two dimensional radial symmetric Disk model.

Gaussian1D([amplitude, mean, stddev])

One dimensional Gaussian model.

Gaussian2D([amplitude, x_mean, y_mean, …])

Two dimensional Gaussian model.

Linear1D([slope, intercept])

One dimensional Line model.

Lorentz1D([amplitude, x_0, fwhm])

One dimensional Lorentzian model.

RickerWavelet1D([amplitude, x_0, sigma])

One dimensional Ricker Wavelet model (sometimes known as a “Mexican Hat” model).

RickerWavelet2D([amplitude, x_0, y_0, sigma])

Two dimensional Ricker Wavelet model (sometimes known as a “Mexican Hat” model).

RedshiftScaleFactor([z])

One dimensional redshift scale factor model.

Multiply([factor])

Multiply a model by a quantity or number.

Planar2D([slope_x, slope_y, intercept])

Two dimensional Plane model.

Scale([factor])

Multiply a model by a dimensionless factor.

Sersic1D([amplitude, r_eff, n])

One dimensional Sersic surface brightness profile.

Sersic2D([amplitude, r_eff, n, x_0, y_0, …])

Two dimensional Sersic surface brightness profile.

Shift([offset])

Shift a coordinate.

Sine1D([amplitude, frequency, phase])

One dimensional Sine model.

Trapezoid1D([amplitude, x_0, width, slope])

One dimensional Trapezoid model.

TrapezoidDisk2D([amplitude, x_0, y_0, R_0, …])

Two dimensional circular Trapezoid model.

Ring2D([amplitude, x_0, y_0, r_in, width, r_out])

Two dimensional radial symmetric Ring model.

Voigt1D([x_0, amplitude_L, fwhm_L, fwhm_G])

One dimensional model for the Voigt profile.

KingProjectedAnalytic1D([amplitude, r_core, …])

Projected (surface density) analytic King Model.

Exponential1D([amplitude, tau])

One dimensional exponential model.

Logarithmic1D([amplitude, tau])

One dimensional logarithmic model.

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.functional_models.AiryDisk2D, astropy.modeling.functional_models.Moffat1D, astropy.modeling.functional_models.Moffat2D, astropy.modeling.functional_models.Box1D, astropy.modeling.functional_models.Box2D, astropy.modeling.functional_models.Const1D, astropy.modeling.functional_models.Const2D, astropy.modeling.functional_models.Ellipse2D, astropy.modeling.functional_models.Disk2D, astropy.modeling.functional_models.Gaussian1D, astropy.modeling.functional_models.Gaussian2D, astropy.modeling.functional_models.Linear1D, astropy.modeling.functional_models.Lorentz1D, astropy.modeling.functional_models.RickerWavelet1D, astropy.modeling.functional_models.RickerWavelet2D, astropy.modeling.functional_models.RedshiftScaleFactor, astropy.modeling.functional_models.Multiply, astropy.modeling.functional_models.Planar2D, astropy.modeling.functional_models.Scale, astropy.modeling.functional_models.Sersic1D, astropy.modeling.functional_models.Sersic2D, astropy.modeling.functional_models.Shift, astropy.modeling.functional_models.Sine1D, astropy.modeling.functional_models.Trapezoid1D, astropy.modeling.functional_models.TrapezoidDisk2D, astropy.modeling.functional_models.Ring2D, astropy.modeling.functional_models.Voigt1D, astropy.modeling.functional_models.KingProjectedAnalytic1D, astropy.modeling.functional_models.Exponential1D, astropy.modeling.functional_models.Logarithmic1D

astropy.modeling.physical_models Module

Models that have physical origins.

Classes

BlackBody([temperature, scale])

Blackbody model using the Planck function.

Drude1D([amplitude, x_0, fwhm])

Drude model based one the behavior of electons in materials (esp.

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.physical_models.BlackBody, astropy.modeling.physical_models.Drude1D

astropy.modeling.powerlaws Module

Power law model variants

Classes

PowerLaw1D([amplitude, x_0, alpha])

One dimensional power law model.

BrokenPowerLaw1D([amplitude, x_break, …])

One dimensional power law model with a break.

SmoothlyBrokenPowerLaw1D([amplitude, …])

One dimensional smoothly broken power law model.

ExponentialCutoffPowerLaw1D([amplitude, …])

One dimensional power law model with an exponential cutoff.

LogParabola1D([amplitude, x_0, alpha, beta])

One dimensional log parabola model (sometimes called curved power law).

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.powerlaws.PowerLaw1D, astropy.modeling.powerlaws.BrokenPowerLaw1D, astropy.modeling.powerlaws.SmoothlyBrokenPowerLaw1D, astropy.modeling.powerlaws.ExponentialCutoffPowerLaw1D, astropy.modeling.powerlaws.LogParabola1D

astropy.modeling.polynomial Module

This module contains models representing polynomials and polynomial series.

Classes

Chebyshev1D(degree[, domain, window, …])

Univariate Chebyshev series.

Chebyshev2D(x_degree, y_degree[, x_domain, …])

Bivariate Chebyshev series..

Hermite1D(degree[, domain, window, …])

Univariate Hermite series.

Hermite2D(x_degree, y_degree[, x_domain, …])

Bivariate Hermite series.

InverseSIP(ap_order, bp_order[, ap_coeff, …])

Inverse Simple Imaging Polynomial

Legendre1D(degree[, domain, window, …])

Univariate Legendre series.

Legendre2D(x_degree, y_degree[, x_domain, …])

Bivariate Legendre series.

Polynomial1D(degree[, domain, window, …])

1D Polynomial model.

Polynomial2D(degree[, x_domain, y_domain, …])

2D Polynomial model.

SIP(crpix, a_order, b_order[, a_coeff, …])

Simple Imaging Polynomial (SIP) model.

OrthoPolynomialBase(x_degree, y_degree[, …])

This is a base class for the 2D Chebyshev and Legendre models.

PolynomialModel(degree[, n_models, …])

Base class for polynomial models.

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.polynomial.Chebyshev1D, astropy.modeling.polynomial.Chebyshev2D, astropy.modeling.polynomial.Hermite1D, astropy.modeling.polynomial.Hermite2D, astropy.modeling.polynomial.InverseSIP, astropy.modeling.polynomial.Legendre1D, astropy.modeling.polynomial.Legendre2D, astropy.modeling.polynomial.Polynomial1D, astropy.modeling.polynomial.Polynomial2D, astropy.modeling.polynomial.SIP, astropy.modeling.polynomial.OrthoPolynomialBase, astropy.modeling.polynomial.PolynomialModel

astropy.modeling.projections Module

Implements projections–particularly sky projections defined in WCS Paper II [1].

All angles are set and and displayed in degrees but internally computations are performed in radians. All functions expect inputs and outputs degrees.

References

1

Calabretta, M.R., Greisen, E.W., 2002, A&A, 395, 1077 (Paper II)

Classes

Projection(*args[, meta, name])

Base class for all sky projections.

Pix2SkyProjection(*args, **kwargs)

Base class for all Pix2Sky projections.

Sky2PixProjection(*args, **kwargs)

Base class for all Sky2Pix projections.

Zenithal(*args[, meta, name])

Base class for all Zenithal projections.

Cylindrical(*args[, meta, name])

Base class for Cylindrical projections.

PseudoCylindrical(*args[, meta, name])

Base class for pseudocylindrical projections.

Conic(*args[, meta, name])

Base class for conic projections.

PseudoConic(*args[, meta, name])

Base class for pseudoconic projections.

QuadCube(*args[, meta, name])

Base class for quad cube projections.

HEALPix(*args[, meta, name])

Base class for HEALPix projections.

AffineTransformation2D([matrix, translation])

Perform an affine transformation in 2 dimensions.

Pix2Sky_ZenithalPerspective([mu, gamma])

Zenithal perspective projection - pixel to sky.

Sky2Pix_ZenithalPerspective([mu, gamma])

Zenithal perspective projection - sky to pixel.

Pix2Sky_SlantZenithalPerspective([mu, phi0, …])

Slant zenithal perspective projection - pixel to sky.

Sky2Pix_SlantZenithalPerspective([mu, phi0, …])

Zenithal perspective projection - sky to pixel.

Pix2Sky_Gnomonic(*args, **kwargs)

Gnomonic projection - pixel to sky.

Sky2Pix_Gnomonic(*args, **kwargs)

Gnomonic Projection - sky to pixel.

Pix2Sky_Stereographic(*args, **kwargs)

Stereographic Projection - pixel to sky.

Sky2Pix_Stereographic(*args, **kwargs)

Stereographic Projection - sky to pixel.

Pix2Sky_SlantOrthographic([xi, eta])

Slant orthographic projection - pixel to sky.

Sky2Pix_SlantOrthographic([xi, eta])

Slant orthographic projection - sky to pixel.

Pix2Sky_ZenithalEquidistant(*args, **kwargs)

Zenithal equidistant projection - pixel to sky.

Sky2Pix_ZenithalEquidistant(*args, **kwargs)

Zenithal equidistant projection - sky to pixel.

Pix2Sky_ZenithalEqualArea(*args, **kwargs)

Zenithal equidistant projection - pixel to sky.

Sky2Pix_ZenithalEqualArea(*args, **kwargs)

Zenithal equidistant projection - sky to pixel.

Pix2Sky_Airy([theta_b])

Airy projection - pixel to sky.

Sky2Pix_Airy([theta_b])

Airy - sky to pixel.

Pix2Sky_CylindricalPerspective([mu, lam])

Cylindrical perspective - pixel to sky.

Sky2Pix_CylindricalPerspective([mu, lam])

Cylindrical Perspective - sky to pixel.

Pix2Sky_CylindricalEqualArea([lam])

Cylindrical equal area projection - pixel to sky.

Sky2Pix_CylindricalEqualArea([lam])

Cylindrical equal area projection - sky to pixel.

Pix2Sky_PlateCarree(*args, **kwargs)

Plate carrée projection - pixel to sky.

Sky2Pix_PlateCarree(*args, **kwargs)

Plate carrée projection - sky to pixel.

Pix2Sky_Mercator(*args, **kwargs)

Mercator - pixel to sky.

Sky2Pix_Mercator(*args, **kwargs)

Mercator - sky to pixel.

Pix2Sky_SansonFlamsteed(*args, **kwargs)

Sanson-Flamsteed projection - pixel to sky.

Sky2Pix_SansonFlamsteed(*args, **kwargs)

Sanson-Flamsteed projection - sky to pixel.

Pix2Sky_Parabolic(*args, **kwargs)

Parabolic projection - pixel to sky.

Sky2Pix_Parabolic(*args, **kwargs)

Parabolic projection - sky to pixel.

Pix2Sky_Molleweide(*args, **kwargs)

Molleweide’s projection - pixel to sky.

Sky2Pix_Molleweide(*args, **kwargs)

Molleweide’s projection - sky to pixel.

Pix2Sky_HammerAitoff(*args, **kwargs)

Hammer-Aitoff projection - pixel to sky.

Sky2Pix_HammerAitoff(*args, **kwargs)

Hammer-Aitoff projection - sky to pixel.

Pix2Sky_ConicPerspective(*args, **kwargs)

Colles’ conic perspective projection - pixel to sky.

Sky2Pix_ConicPerspective(*args, **kwargs)

Colles’ conic perspective projection - sky to pixel.

Pix2Sky_ConicEqualArea(*args, **kwargs)

Alber’s conic equal area projection - pixel to sky.

Sky2Pix_ConicEqualArea(*args, **kwargs)

Alber’s conic equal area projection - sky to pixel.

Pix2Sky_ConicEquidistant(*args, **kwargs)

Conic equidistant projection - pixel to sky.

Sky2Pix_ConicEquidistant(*args, **kwargs)

Conic equidistant projection - sky to pixel.

Pix2Sky_ConicOrthomorphic(*args, **kwargs)

Conic orthomorphic projection - pixel to sky.

Sky2Pix_ConicOrthomorphic(*args, **kwargs)

Conic orthomorphic projection - sky to pixel.

Pix2Sky_BonneEqualArea([theta1])

Bonne’s equal area pseudoconic projection - pixel to sky.

Sky2Pix_BonneEqualArea([theta1])

Bonne’s equal area pseudoconic projection - sky to pixel.

Pix2Sky_Polyconic(*args, **kwargs)

Polyconic projection - pixel to sky.

Sky2Pix_Polyconic(*args, **kwargs)

Polyconic projection - sky to pixel.

Pix2Sky_TangentialSphericalCube(*args, **kwargs)

Tangential spherical cube projection - pixel to sky.

Sky2Pix_TangentialSphericalCube(*args, **kwargs)

Tangential spherical cube projection - sky to pixel.

Pix2Sky_COBEQuadSphericalCube(*args, **kwargs)

COBE quadrilateralized spherical cube projection - pixel to sky.

Sky2Pix_COBEQuadSphericalCube(*args, **kwargs)

COBE quadrilateralized spherical cube projection - sky to pixel.

Pix2Sky_QuadSphericalCube(*args, **kwargs)

Quadrilateralized spherical cube projection - pixel to sky.

Sky2Pix_QuadSphericalCube(*args, **kwargs)

Quadrilateralized spherical cube projection - sky to pixel.

Pix2Sky_HEALPix([H, X])

HEALPix - pixel to sky.

Sky2Pix_HEALPix([H, X])

HEALPix projection - sky to pixel.

Pix2Sky_HEALPixPolar(*args, **kwargs)

HEALPix polar, aka “butterfly” projection - pixel to sky.

Sky2Pix_HEALPixPolar(*args, **kwargs)

HEALPix polar, aka “butterfly” projection - pixel to sky.

Pix2Sky_AZP

alias of astropy.modeling.projections.Pix2Sky_ZenithalPerspective

Sky2Pix_AZP

alias of astropy.modeling.projections.Sky2Pix_ZenithalPerspective

Pix2Sky_SZP

alias of astropy.modeling.projections.Pix2Sky_SlantZenithalPerspective

Sky2Pix_SZP

alias of astropy.modeling.projections.Sky2Pix_SlantZenithalPerspective

Pix2Sky_TAN

alias of astropy.modeling.projections.Pix2Sky_Gnomonic

Sky2Pix_TAN

alias of astropy.modeling.projections.Sky2Pix_Gnomonic

Pix2Sky_STG

alias of astropy.modeling.projections.Pix2Sky_Stereographic

Sky2Pix_STG

alias of astropy.modeling.projections.Sky2Pix_Stereographic

Pix2Sky_SIN

alias of astropy.modeling.projections.Pix2Sky_SlantOrthographic

Sky2Pix_SIN

alias of astropy.modeling.projections.Sky2Pix_SlantOrthographic

Pix2Sky_ARC

alias of astropy.modeling.projections.Pix2Sky_ZenithalEquidistant

Sky2Pix_ARC

alias of astropy.modeling.projections.Sky2Pix_ZenithalEquidistant

Pix2Sky_ZEA

alias of astropy.modeling.projections.Pix2Sky_ZenithalEqualArea

Sky2Pix_ZEA

alias of astropy.modeling.projections.Sky2Pix_ZenithalEqualArea

Pix2Sky_AIR

alias of astropy.modeling.projections.Pix2Sky_Airy

Sky2Pix_AIR

alias of astropy.modeling.projections.Sky2Pix_Airy

Pix2Sky_CYP

alias of astropy.modeling.projections.Pix2Sky_CylindricalPerspective

Sky2Pix_CYP

alias of astropy.modeling.projections.Sky2Pix_CylindricalPerspective

Pix2Sky_CEA

alias of astropy.modeling.projections.Pix2Sky_CylindricalEqualArea

Sky2Pix_CEA

alias of astropy.modeling.projections.Sky2Pix_CylindricalEqualArea

Pix2Sky_CAR

alias of astropy.modeling.projections.Pix2Sky_PlateCarree

Sky2Pix_CAR

alias of astropy.modeling.projections.Sky2Pix_PlateCarree

Pix2Sky_MER

alias of astropy.modeling.projections.Pix2Sky_Mercator

Sky2Pix_MER

alias of astropy.modeling.projections.Sky2Pix_Mercator

Pix2Sky_SFL

alias of astropy.modeling.projections.Pix2Sky_SansonFlamsteed

Sky2Pix_SFL

alias of astropy.modeling.projections.Sky2Pix_SansonFlamsteed

Pix2Sky_PAR

alias of astropy.modeling.projections.Pix2Sky_Parabolic

Sky2Pix_PAR

alias of astropy.modeling.projections.Sky2Pix_Parabolic

Pix2Sky_MOL

alias of astropy.modeling.projections.Pix2Sky_Molleweide

Sky2Pix_MOL

alias of astropy.modeling.projections.Sky2Pix_Molleweide

Pix2Sky_AIT

alias of astropy.modeling.projections.Pix2Sky_HammerAitoff

Sky2Pix_AIT

alias of astropy.modeling.projections.Sky2Pix_HammerAitoff

Pix2Sky_COP

alias of astropy.modeling.projections.Pix2Sky_ConicPerspective

Sky2Pix_COP

alias of astropy.modeling.projections.Sky2Pix_ConicPerspective

Pix2Sky_COE

alias of astropy.modeling.projections.Pix2Sky_ConicEqualArea

Sky2Pix_COE

alias of astropy.modeling.projections.Sky2Pix_ConicEqualArea

Pix2Sky_COD

alias of astropy.modeling.projections.Pix2Sky_ConicEquidistant

Sky2Pix_COD

alias of astropy.modeling.projections.Sky2Pix_ConicEquidistant

Pix2Sky_COO

alias of astropy.modeling.projections.Pix2Sky_ConicOrthomorphic

Sky2Pix_COO

alias of astropy.modeling.projections.Sky2Pix_ConicOrthomorphic

Pix2Sky_BON

alias of astropy.modeling.projections.Pix2Sky_BonneEqualArea

Sky2Pix_BON

alias of astropy.modeling.projections.Sky2Pix_BonneEqualArea

Pix2Sky_PCO

alias of astropy.modeling.projections.Pix2Sky_Polyconic

Sky2Pix_PCO

alias of astropy.modeling.projections.Sky2Pix_Polyconic

Pix2Sky_TSC

alias of astropy.modeling.projections.Pix2Sky_TangentialSphericalCube

Sky2Pix_TSC

alias of astropy.modeling.projections.Sky2Pix_TangentialSphericalCube

Pix2Sky_CSC

alias of astropy.modeling.projections.Pix2Sky_COBEQuadSphericalCube

Sky2Pix_CSC

alias of astropy.modeling.projections.Sky2Pix_COBEQuadSphericalCube

Pix2Sky_QSC

alias of astropy.modeling.projections.Pix2Sky_QuadSphericalCube

Sky2Pix_QSC

alias of astropy.modeling.projections.Sky2Pix_QuadSphericalCube

Pix2Sky_HPX

alias of astropy.modeling.projections.Pix2Sky_HEALPix

Sky2Pix_HPX

alias of astropy.modeling.projections.Sky2Pix_HEALPix

Pix2Sky_XPH

alias of astropy.modeling.projections.Pix2Sky_HEALPixPolar

Sky2Pix_XPH

alias of astropy.modeling.projections.Sky2Pix_HEALPixPolar

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.projections.Projection, astropy.modeling.projections.Pix2SkyProjection, astropy.modeling.projections.Sky2PixProjection, astropy.modeling.projections.Zenithal, astropy.modeling.projections.Cylindrical, astropy.modeling.projections.PseudoCylindrical, astropy.modeling.projections.Conic, astropy.modeling.projections.PseudoConic, astropy.modeling.projections.QuadCube, astropy.modeling.projections.HEALPix, astropy.modeling.projections.AffineTransformation2D, astropy.modeling.projections.Pix2Sky_ZenithalPerspective, astropy.modeling.projections.Sky2Pix_ZenithalPerspective, astropy.modeling.projections.Pix2Sky_SlantZenithalPerspective, astropy.modeling.projections.Sky2Pix_SlantZenithalPerspective, astropy.modeling.projections.Pix2Sky_Gnomonic, astropy.modeling.projections.Sky2Pix_Gnomonic, astropy.modeling.projections.Pix2Sky_Stereographic, astropy.modeling.projections.Sky2Pix_Stereographic, astropy.modeling.projections.Pix2Sky_SlantOrthographic, astropy.modeling.projections.Sky2Pix_SlantOrthographic, astropy.modeling.projections.Pix2Sky_ZenithalEquidistant, astropy.modeling.projections.Sky2Pix_ZenithalEquidistant, astropy.modeling.projections.Pix2Sky_ZenithalEqualArea, astropy.modeling.projections.Sky2Pix_ZenithalEqualArea, astropy.modeling.projections.Pix2Sky_Airy, astropy.modeling.projections.Sky2Pix_Airy, astropy.modeling.projections.Pix2Sky_CylindricalPerspective, astropy.modeling.projections.Sky2Pix_CylindricalPerspective, astropy.modeling.projections.Pix2Sky_CylindricalEqualArea, astropy.modeling.projections.Sky2Pix_CylindricalEqualArea, astropy.modeling.projections.Pix2Sky_PlateCarree, astropy.modeling.projections.Sky2Pix_PlateCarree, astropy.modeling.projections.Pix2Sky_Mercator, astropy.modeling.projections.Sky2Pix_Mercator, astropy.modeling.projections.Pix2Sky_SansonFlamsteed, astropy.modeling.projections.Sky2Pix_SansonFlamsteed, astropy.modeling.projections.Pix2Sky_Parabolic, astropy.modeling.projections.Sky2Pix_Parabolic, astropy.modeling.projections.Pix2Sky_Molleweide, astropy.modeling.projections.Sky2Pix_Molleweide, astropy.modeling.projections.Pix2Sky_HammerAitoff, astropy.modeling.projections.Sky2Pix_HammerAitoff, astropy.modeling.projections.Pix2Sky_ConicPerspective, astropy.modeling.projections.Sky2Pix_ConicPerspective, astropy.modeling.projections.Pix2Sky_ConicEqualArea, astropy.modeling.projections.Sky2Pix_ConicEqualArea, astropy.modeling.projections.Pix2Sky_ConicEquidistant, astropy.modeling.projections.Sky2Pix_ConicEquidistant, astropy.modeling.projections.Pix2Sky_ConicOrthomorphic, astropy.modeling.projections.Sky2Pix_ConicOrthomorphic, astropy.modeling.projections.Pix2Sky_BonneEqualArea, astropy.modeling.projections.Sky2Pix_BonneEqualArea, astropy.modeling.projections.Pix2Sky_Polyconic, astropy.modeling.projections.Sky2Pix_Polyconic, astropy.modeling.projections.Pix2Sky_TangentialSphericalCube, astropy.modeling.projections.Sky2Pix_TangentialSphericalCube, astropy.modeling.projections.Pix2Sky_COBEQuadSphericalCube, astropy.modeling.projections.Sky2Pix_COBEQuadSphericalCube, astropy.modeling.projections.Pix2Sky_QuadSphericalCube, astropy.modeling.projections.Sky2Pix_QuadSphericalCube, astropy.modeling.projections.Pix2Sky_HEALPix, astropy.modeling.projections.Sky2Pix_HEALPix, astropy.modeling.projections.Pix2Sky_HEALPixPolar, astropy.modeling.projections.Sky2Pix_HEALPixPolar, astropy.modeling.projections.Pix2Sky_ZenithalPerspective, astropy.modeling.projections.Sky2Pix_ZenithalPerspective, astropy.modeling.projections.Pix2Sky_SlantZenithalPerspective, astropy.modeling.projections.Sky2Pix_SlantZenithalPerspective, astropy.modeling.projections.Pix2Sky_Gnomonic, astropy.modeling.projections.Sky2Pix_Gnomonic, astropy.modeling.projections.Pix2Sky_Stereographic, astropy.modeling.projections.Sky2Pix_Stereographic, astropy.modeling.projections.Pix2Sky_SlantOrthographic, astropy.modeling.projections.Sky2Pix_SlantOrthographic, astropy.modeling.projections.Pix2Sky_ZenithalEquidistant, astropy.modeling.projections.Sky2Pix_ZenithalEquidistant, astropy.modeling.projections.Pix2Sky_ZenithalEqualArea, astropy.modeling.projections.Sky2Pix_ZenithalEqualArea, astropy.modeling.projections.Pix2Sky_Airy, astropy.modeling.projections.Sky2Pix_Airy, astropy.modeling.projections.Pix2Sky_CylindricalPerspective, astropy.modeling.projections.Sky2Pix_CylindricalPerspective, astropy.modeling.projections.Pix2Sky_CylindricalEqualArea, astropy.modeling.projections.Sky2Pix_CylindricalEqualArea, astropy.modeling.projections.Pix2Sky_PlateCarree, astropy.modeling.projections.Sky2Pix_PlateCarree, astropy.modeling.projections.Pix2Sky_Mercator, astropy.modeling.projections.Sky2Pix_Mercator, astropy.modeling.projections.Pix2Sky_SansonFlamsteed, astropy.modeling.projections.Sky2Pix_SansonFlamsteed, astropy.modeling.projections.Pix2Sky_Parabolic, astropy.modeling.projections.Sky2Pix_Parabolic, astropy.modeling.projections.Pix2Sky_Molleweide, astropy.modeling.projections.Sky2Pix_Molleweide, astropy.modeling.projections.Pix2Sky_HammerAitoff, astropy.modeling.projections.Sky2Pix_HammerAitoff, astropy.modeling.projections.Pix2Sky_ConicPerspective, astropy.modeling.projections.Sky2Pix_ConicPerspective, astropy.modeling.projections.Pix2Sky_ConicEqualArea, astropy.modeling.projections.Sky2Pix_ConicEqualArea, astropy.modeling.projections.Pix2Sky_ConicEquidistant, astropy.modeling.projections.Sky2Pix_ConicEquidistant, astropy.modeling.projections.Pix2Sky_ConicOrthomorphic, astropy.modeling.projections.Sky2Pix_ConicOrthomorphic, astropy.modeling.projections.Pix2Sky_BonneEqualArea, astropy.modeling.projections.Sky2Pix_BonneEqualArea, astropy.modeling.projections.Pix2Sky_Polyconic, astropy.modeling.projections.Sky2Pix_Polyconic, astropy.modeling.projections.Pix2Sky_TangentialSphericalCube, astropy.modeling.projections.Sky2Pix_TangentialSphericalCube, astropy.modeling.projections.Pix2Sky_COBEQuadSphericalCube, astropy.modeling.projections.Sky2Pix_COBEQuadSphericalCube, astropy.modeling.projections.Pix2Sky_QuadSphericalCube, astropy.modeling.projections.Sky2Pix_QuadSphericalCube, astropy.modeling.projections.Pix2Sky_HEALPix, astropy.modeling.projections.Sky2Pix_HEALPix, astropy.modeling.projections.Pix2Sky_HEALPixPolar, astropy.modeling.projections.Sky2Pix_HEALPixPolar

astropy.modeling.rotations Module

Implements rotations, including spherical rotations as defined in WCS Paper II [1]

RotateNative2Celestial and RotateCelestial2Native follow the convention in WCS Paper II to rotate to/from a native sphere and the celestial sphere.

The implementation uses EulerAngleRotation. The model parameters are three angles: the longitude (lon) and latitude (lat) of the fiducial point in the celestial system (CRVAL keywords in FITS), and the longitude of the celestial pole in the native system (lon_pole). The Euler angles are lon+90, 90-lat and -(lon_pole-90).

References

1

Calabretta, M.R., Greisen, E.W., 2002, A&A, 395, 1077 (Paper II)

Classes

RotateCelestial2Native(lon, lat, lon_pole, …)

Transform from Celestial to Native Spherical Coordinates.

RotateNative2Celestial(lon, lat, lon_pole, …)

Transform from Native to Celestial Spherical Coordinates.

Rotation2D([angle])

Perform a 2D rotation given an angle.

EulerAngleRotation(phi, theta, psi, …)

Implements Euler angle intrinsic rotations.

RotationSequence3D(angles, axes_order[, name])

Perform a series of rotations about different axis in 3D space.

SphericalRotationSequence(angles, axes_order)

Perform a sequence of rotations about arbitrary number of axes in spherical coordinates.

Class Inheritance Diagram

Inheritance diagram of astropy.modeling.rotations.RotateCelestial2Native, astropy.modeling.rotations.RotateNative2Celestial, astropy.modeling.rotations.Rotation2D, astropy.modeling.rotations.EulerAngleRotation, astropy.modeling.rotations.RotationSequence3D, astropy.modeling.rotations.SphericalRotationSequence

class astropy.modeling.tabular.Tabular1D(points=None, lookup_table=None, method='linear', bounds_error=True, fill_value=nan, **kwargs)

Tabular model in 1D. Returns an interpolated lookup table value.

Parameters
pointsarray_like of float of ndim=1.

The points defining the regular grid in n dimensions.

lookup_tablearray_like, of ndim=1.

The data in one dimensions.

methodstr, optional

The method of interpolation to perform. Supported are “linear” and “nearest”, and “splinef2d”. “splinef2d” is only supported for 2-dimensional data. Default is “linear”.

bounds_errorbool, optional

If True, when interpolated values are requested outside of the domain of the input data, a ValueError is raised. If False, then fill_value is used.

fill_valuefloat, optional

If provided, the value to use for points outside of the interpolation domain. If None, values outside the domain are extrapolated. Extrapolation is not supported by method “splinef2d”.

Returns
valuendarray

Interpolated values at input coordinates.

Raises
ImportError

Scipy is not installed.

Notes

Uses scipy.interpolate.interpn.

class astropy.modeling.tabular.Tabular2D(points=None, lookup_table=None, method='linear', bounds_error=True, fill_value=nan, **kwargs)

Tabular model in 2D. Returns an interpolated lookup table value.

Parameters
pointstuple of ndarray of float, with shapes (m1, m2), optional

The points defining the regular grid in n dimensions.

lookup_tablearray_like, shape (m1, m2)

The data on a regular grid in 2 dimensions.

methodstr, optional

The method of interpolation to perform. Supported are “linear” and “nearest”, and “splinef2d”. “splinef2d” is only supported for 2-dimensional data. Default is “linear”.

bounds_errorbool, optional

If True, when interpolated values are requested outside of the domain of the input data, a ValueError is raised. If False, then fill_value is used.

fill_valuefloat, optional

If provided, the value to use for points outside of the interpolation domain. If None, values outside the domain are extrapolated. Extrapolation is not supported by method “splinef2d”.

Returns
valuendarray

Interpolated values at input coordinates.

Raises
ImportError

Scipy is not installed.

Notes

Uses scipy.interpolate.interpn.