AsinhStretch

class astropy.visualization.AsinhStretch(a=0.1)[source] [edit on github]

Bases: astropy.visualization.BaseStretch

An asinh stretch.

The stretch is given by:

\[y = \frac{{\rm asinh}(x / a)}{{\rm asinh}(1 / a)}.\]
Parameters:

a : float, optional

The a parameter used in the above formula. The value of this parameter is where the asinh curve transitions from linear to logarithmic behavior, expressed as a fraction of the normalized image. Must be in the range between 0 and 1. Default is 0.1

Attributes Summary

inverse A stretch object that performs the inverse operation.

Methods Summary

__call__(values[, clip, out]) Transform values using this stretch.

Attributes Documentation

inverse

A stretch object that performs the inverse operation.

Methods Documentation

__call__(values, clip=True, out=None)[source] [edit on github]

Transform values using this stretch.

Parameters:

values : array-like

The input values, which should already be normalized to the [0:1] range.

clip : bool, optional

If True (default), values outside the [0:1] range are clipped to the [0:1] range.

out : ndarray, optional

If specified, the output values will be placed in this array (typically used for in-place calculations).

Returns:

result : ndarray

The transformed values.