AsinhStretch#

class astropy.visualization.AsinhStretch(a=0.1)[source]#

Bases: BaseStretch

An asinh stretch.

The stretch is given by:

\[y = \frac{{\rm asinh}(x / a)}{{\rm asinh}(1 / a)}.\]
Parameters:
apython: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. The stretch becomes more linear for larger a values and more logarithmic for smaller a values. a must be greater than 0. Default is 0.1.

Examples

(Source code, png, svg, pdf)

../_images/astropy-visualization-AsinhStretch-1.png

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]#

Transform values using this stretch.

Parameters:
valuesnumpy:array_like

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

clipbool, optional

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

outndarray, optional

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

Returns:
resultndarray

The transformed values.