PowerDistStretch¶
- class astropy.visualization.PowerDistStretch(a=1000.0)[source]¶
Bases:
BaseStretch
An alternative power stretch.
The stretch is given by:
\[y = \frac{a^x - 1}{a - 1}\]- Parameters:
- a
python:float
, optional The
a
parameter used in the above formula.a
must be greater than or equal to 0, but cannot be set to 1. Default is 1000.
- a
Attributes Summary
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.- 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.
- result