PowerDistStretch

class astropy.visualization.PowerDistStretch(a=1000.0)

Bases: BaseStretch

An alternative power stretch.

The stretch is given by:

\[y = \frac{a^x - 1}{a - 1}\]

Parameters:

apython:float, optional

The a parameter used in the above formula. The stretch becomes more linear as a approaches 1, more exponential for a values greater than 1, and more logarithmic for a values less than 1. a must be greater than 0, but cannot be set to 1. Default is 1000.

Examples

(Source code, png, svg, pdf)

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)

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.