arch.univariate.Normal

class arch.univariate.Normal(*, seed: int | RandomState | Generator | None = None)[source]

Standard normal distribution for use with ARCH models.

Parameters:
seed: int | RandomState | Generator | None = None

Random number generator instance or int to use. Set to ensure reproducibility. If using an int, which must not be negative, the argument is passed to np.random.default_rng. If not provided, default_rng is used with system-provided entropy.

Raises:
  • TypeError – If seed is not None, an integer, a Generator or a RandomState.

  • ValueError – If seed is a negative integer.

Methods

bounds(resids)

Construct parameter bounds for use in optimization.

cdf(resids[, parameters])

Compute the cumulative distribution function.

constraints()

Construct arrays to use in constrained optimization.

loglikelihood(parameters, resids, sigma2[, ...])

Compute the log-likelihood of normally distributed residuals.

moment(n[, parameters])

Compute the moment of order n.

parameter_names()

Return the names of the distribution shape parameters.

partial_moment(n[, z, parameters])

Compute the order n lower partial moment from -inf to z.

ppf(pits[, parameters])

Compute the inverse cumulative density function (ICDF).

simulate(parameters)

Simulate i.i.d.

starting_values(std_resid)

Construct starting values for use in optimization.

Properties

generator

The NumPy Generator or RandomState attached to the distribution.

name

The name of the distribution.