BrokenPowerLaw1D¶

class astropy.modeling.powerlaws.BrokenPowerLaw1D(amplitude, x_break, alpha_1, alpha_2, **constraints)[source] [edit on github]¶

Bases: astropy.modeling.Fittable1DModel

One dimensional power law model with a break.

Parameters:

amplitude : float

Model amplitude at the break point

x_break : float

Break point

alpha_1 : float

Power law index for x < x_break

alpha_2 : float

Power law index for x > x_break

Notes

Model formula (with $A$ for amplitude and $\alpha_1$ for alpha_1 and $\alpha_2$ for alpha_2):

$f(x) = \left \{ \begin{array}{ll} A (x / x_{break}) ^ {-\alpha_1} & : x < x_{break} \\ A (x / x_{break}) ^ {-\alpha_2} & : x > x_{break} \\ \end{array} \right.$

Attributes Summary

`alpha_1`
`alpha_2`
`amplitude`
`input_names`	list() -> new empty list
`param_names`	list() -> new empty list
`x_break`

Methods Summary

`eval`(args, *kwargs)	Deprecated since version 1.0.
`evaluate`(x, amplitude, x_break, alpha_1, alpha_2)	One dimensional broken power law model function
`fit_deriv`(x, amplitude, x_break, alpha_1, ...)	One dimensional broken power law derivative with respect to parameters

Attributes Documentation

alpha_1¶

alpha_2¶

amplitude¶

input_names = ['x']¶

param_names = ['amplitude', 'x_break', 'alpha_1', 'alpha_2']¶

x_break¶

Methods Documentation

static eval(*args, **kwargs) [edit on github]¶: Deprecated since version 1.0: The eval method is deprecated and may be removed in a future version. Use BrokenPowerLaw1D.evaluate instead.

One dimensional broken power law model function

static evaluate(x, amplitude, x_break, alpha_1, alpha_2)[source] [edit on github]¶: One dimensional broken power law model function

static fit_deriv(x, amplitude, x_break, alpha_1, alpha_2)[source] [edit on github]¶: One dimensional broken power law derivative with respect to parameters

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BrokenPowerLaw1D¶

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