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. The stretch becomes more linear asa
approaches 1, more exponential fora
values greater than 1, and more logarithmic fora
values less than 1.a
must be greater than 0, but cannot be set to 1. Default is 1000.
- a
Examples
(
Source code
,png
,svg
,pdf
)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