colour.Extrapolator¶
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class
colour.
Extrapolator
(interpolator=None, method='Linear', left=None, right=None, dtype=<class 'numpy.float64'>)[source]¶ Extrapolates the 1-D function of given interpolator.
The
colour.Extrapolator
class acts as a wrapper around a given Colour or scipy interpolator class instance with compatible signature. Two extrapolation methods are available:Linear: Linearly extrapolates given points using the slope defined by the interpolator boundaries (xi[0], xi[1]) if x < xi[0] and (xi[-1], xi[-2]) if x > xi[-1].
Constant: Extrapolates given points by assigning the interpolator boundaries values xi[0] if x < xi[0] and xi[-1] if x > xi[-1].
Specifying the left and right arguments takes precedence on the chosen extrapolation method and will assign the respective left and right values to the given points.
- Parameters
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__class__
()¶
Notes
The interpolator must define x and y attributes.
References
Examples
Extrapolating a single numeric variable:
>>> from colour.algebra import LinearInterpolator >>> x = np.array([3, 4, 5]) >>> y = np.array([1, 2, 3]) >>> interpolator = LinearInterpolator(x, y) >>> extrapolator = Extrapolator(interpolator) >>> extrapolator(1) -1.0
Extrapolating an array_like variable:
>>> extrapolator(np.array([6, 7 , 8])) array([ 4., 5., 6.])
Using the Constant extrapolation method:
>>> x = np.array([3, 4, 5]) >>> y = np.array([1, 2, 3]) >>> interpolator = LinearInterpolator(x, y) >>> extrapolator = Extrapolator(interpolator, method='Constant') >>> extrapolator(np.array([0.1, 0.2, 8, 9])) array([ 1., 1., 3., 3.])
Using defined left boundary and Constant extrapolation method:
>>> x = np.array([3, 4, 5]) >>> y = np.array([1, 2, 3]) >>> interpolator = LinearInterpolator(x, y) >>> extrapolator = Extrapolator(interpolator, method='Constant', left=0) >>> extrapolator(np.array([0.1, 0.2, 8, 9])) array([ 0., 0., 3., 3.])
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__init__
(interpolator=None, method='Linear', left=None, right=None, dtype=<class 'numpy.float64'>)[source]¶ Initialize self. See help(type(self)) for accurate signature.
Methods
__init__
([interpolator, method, left, …])Initialize self.
Attributes
interpolator
Getter and setter property for the Colour or scipy interpolator class instance.
left
Getter and setter property for left value to return for x < xi[0].
method
Getter and setter property for the extrapolation method.
right
Getter and setter property for right value to return for x > xi[-1].