SymmetricInterval

class astropy.visualization.SymmetricInterval(radius=None, *, midpoint=0)

Bases: BaseInterval

Interval based on a symmetric radius away from a midpoint.

Parameters:

radiuspython:float or python:None

The amount the interval extends to either side of the midpoint, so the total interval is twice this value. If None, the radius is automatically determined such that the resulting interval contains both the image minimum and maximum (ignoring NaNs).

midpointpython:float, optional

The midpoint of the symmetric interval. Defaults to zero.

Methods Summary

__call__(values[, clip, out])	Transform values using this interval.
get_limits(values)	Return the minimum and maximum value in the interval based on the values provided.

Methods Documentation

__call__(values, clip=True, out=None)

Transform values using this interval.

The vmin and vmax values are determined by the get_limits method.

The following transformation is then applied to the values:

\[{\rm result} = \frac{{\rm values} - v_{\rm min}} {v_{\rm max} - v_{\rm min}}\]

If clip is True (default), the result is then clipped to the [0:1] range.

Parameters:

valuesnumpy:array_like

The input values.

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.

get_limits(values)

Return the minimum and maximum value in the interval based on the values provided.

Parameters:

valuesndarray

The image values.

Returns:

vmin, vmaxpython:float

The mininium and maximum image value in the interval.