AffineTransformation2D

class astropy.modeling.projections.AffineTransformation2D(matrix=Parameter('matrix', value=[[1. 0.]  [0. 1.]]), translation=Parameter('translation', value=[0. 0.]), **kwargs)

Bases: Model

Perform an affine transformation in 2 dimensions.

Parameters:

matrixarray

A 2x2 matrix specifying the linear transformation to apply to the inputs

translationarray

A 2D vector (given as either a 2x1 or 1x2 array) specifying a translation to apply to the inputs

Attributes Summary

input_units	This property is used to indicate what units or sets of units the evaluate method expects, and returns a dictionary mapping inputs to units (or None if any units are accepted).
matrix
n_inputs	The number of inputs.
n_outputs	The number of outputs.
param_names	Names of the parameters that describe models of this type.
standard_broadcasting
translation

Methods Summary

__call__(*inputs[, model_set_axis, ...])	Evaluate this model using the given input(s) and the parameter values that were specified when the model was instantiated.
evaluate(x, y, matrix, translation)	Apply the transformation to a set of 2D Cartesian coordinates given as two lists--one for the x coordinates and one for a y coordinates--or a single coordinate pair.

Attributes Documentation

input_units

matrix = Parameter('matrix', value=[[1. 0.]  [0. 1.]])

n_inputs = 2

The number of inputs.

n_outputs = 2

The number of outputs.

param_names = ('matrix', 'translation')

Names of the parameters that describe models of this type.

The parameters in this tuple are in the same order they should be passed in when initializing a model of a specific type. Some types of models, such as polynomial models, have a different number of parameters depending on some other property of the model, such as the degree.

When defining a custom model class the value of this attribute is automatically set by the Parameter attributes defined in the class body.

standard_broadcasting = False

translation = Parameter('translation', value=[0. 0.])

Methods Documentation

__call__(*inputs, model_set_axis=None, with_bounding_box=False, fill_value=nan, equivalencies=None, inputs_map=None, **new_inputs)

Evaluate this model using the given input(s) and the parameter values that were specified when the model was instantiated.

classmethod evaluate(x, y, matrix, translation)

Apply the transformation to a set of 2D Cartesian coordinates given as two lists–one for the x coordinates and one for a y coordinates–or a single coordinate pair.

Parameters:

x, yarray, float

x and y coordinates