# Box2D¶

class astropy.modeling.functional_models.Box2D(amplitude=1, x_0=0, y_0=0, x_width=1, y_width=1, **kwargs)[source] [edit on github]

Two dimensional Box model.

Parameters: Other Parameters: amplitude : float Amplitude A x_0 : float x position of the center of the box function x_width : float Width in x direction of the box y_0 : float y position of the center of the box function y_width : float Width in y direction of the box fixed : a dict, optional A dictionary {parameter_name: boolean} of parameters to not be varied during fitting. True means the parameter is held fixed. Alternatively the fixed property of a parameter may be used. tied : dict, optional A dictionary {parameter_name: callable} of parameters which are linked to some other parameter. The dictionary values are callables providing the linking relationship. Alternatively the tied property of a parameter may be used. bounds : dict, optional A dictionary {parameter_name: value} of lower and upper bounds of parameters. Keys are parameter names. Values are a list or a tuple of length 2 giving the desired range for the parameter. Alternatively, the min and max properties of a parameter may be used. eqcons : list, optional A list of functions of length n such that eqcons[j](x0,*args) == 0.0 in a successfully optimized problem. ineqcons : list, optional A list of functions of length n such that ieqcons[j](x0,*args) >= 0.0 is a successfully optimized problem.

Notes

Model formula:

$\begin{split}f(x, y) = \left \{ \begin{array}{ll} A : & x_0 - w_x/2 \leq x \leq x_0 + w_x/2 \text{ and} \\ & y_0 - w_y/2 \leq y \leq y_0 + w_y/2 \\ 0 : & \text{else} \end{array} \right.\end{split}$

Attributes Summary

 amplitude 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). param_names x_0 x_width y_0 y_width

Methods Summary

 evaluate(x, y, amplitude, x_0, y_0, x_width, …) Two dimensional Box model function

Attributes Documentation

amplitude
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).

Model sub-classes can also use function annotations in evaluate to indicate valid input units, in which case this property should not be overridden since it will return the input units based on the annotations.

param_names = ('amplitude', 'x_0', 'y_0', 'x_width', 'y_width')
x_0
x_width
y_0
y_width

Methods Documentation

static evaluate(x, y, amplitude, x_0, y_0, x_width, y_width)[source] [edit on github]

Two dimensional Box model function