chaospy.Logn

class chaospy.Logn(dist, base=2)[source]

Logarithm with base N.

Args:
dist (Distribution):

Distribution to perform transformation on.

base (int, float):

the logarithm base.

Example:
>>> distribution = chaospy.Logn(chaospy.Uniform(1, 2), 3)
>>> distribution
Logn(Uniform(lower=1, upper=2), 3)
>>> q = numpy.linspace(0,1,6)[1:-1]
>>> distribution.inv(q).round(4)
array([0.166 , 0.3063, 0.4278, 0.535 ])
>>> distribution.fwd(distribution.inv(q)).round(4)
array([0.2, 0.4, 0.6, 0.8])
>>> distribution.pdf(distribution.inv(q)).round(4)
array([1.3183, 1.5381, 1.7578, 1.9775])
>>> distribution.sample(4).round(4)
array([0.4578, 0.0991, 0.608 , 0.3582])
>>> distribution.mom(1).round(4)
0.3516
__init__(dist, base=2)[source]

Distribution initializer.

In addition to assigning some object variables, also checks for some consistency issues.

Args:
parameters (Optional[Distribution[str, Union[ndarray, Distribution]]]):

Collection of model parameters.

dependencies (Optional[Sequence[Set[int]]]):

Dependency identifiers. One collection for each dimension.

rotation (Optional[Sequence[int]]):

The order of which to resolve dependencies.

exclusion (Optional[Sequence[int]]):

Distributions that has been “taken out of play” and therefore can not be reused other places in the dependency hierarchy.

repr_args (Optional[Sequence[str]]):

Positional arguments to place in the object string representation. The repr output will then be: <class name>(<arg1>, <arg2>, …).

Raises:
StochasticallyDependentError:

For dependency structures that can not later be rectified. This include under-defined distributions, and inclusion of distributions that should be exclusion.

Methods

pdf(x_data[, decompose, allow_approx, step_size])

Probability density function.

cdf(x_data)

Cumulative distribution function.

fwd(x_data)

Forward Rosenblatt transformation.

inv(q_data[, max_iterations, tollerance])

Inverse Rosenblatt transformation.

sample([size, rule, antithetic, ...])

Create pseudo-random generated samples.

mom(K[, allow_approx])

Raw statistical moments.

ttr(kloc)

Three terms relation's coefficient generator.

Attributes

interpret_as_integer

Flag indicating that return value from the methods sample, and inv should be interpreted as integers instead of floating point.

lower

Lower bound for the distribution.

stochastic_dependent

True if distribution contains stochastically dependent components.

upper

Upper bound for the distribution.