Parameterizations

The pages below provide an overview of the five main supported qp parameterizations:

• Histogram
• Interpolation
• Irregular interpolation
• Gaussian Mixture Model
• Quantile

There exist additional parameterizations, however they are in various stages of completeness and are not guaranteed to work with all of the functions described in the documentation. For more information about these parameterizations see the parameterization API documentation.

SciPy parameterizations

qp also incorporates all of the continuous distributions from scipy.stats as parameterizations, allowing you to create Ensembles parameterized by these distributions. The main limitations on these parameterizations is that they cannot be converted to, as they have no conversion functions. Additionally, their create_ensemble() method takes a data dictionary instead of specific arguments, as shown in the Cookbook.

You can access these parameterizations from the qp.stats module, as shown below:

>>> import qp
>>> ens_n = qp.stats.norm.create_ensemble(dict(loc=np.array([0,1]),scale=np.array([0.25,0.5])))
>>> ens_n
Ensemble(the_class=norm,shape=(2,1))

The available parameterizations are listed below, with links to their SciPy documentation for more information.

Function	Inputs	Description
alpha	a	An alpha continuous random variable.
anglit	loc, scale	An anglit continuous random variable.
arcsine	loc, scale	An arcsine continuous random variable.
argus	chi, loc, scale	Argus distribution
beta	a, b, loc, scale	A beta continuous random variable.
betaprime	a, b, loc, scale	A beta prime continuous random variable.
bradford	c, loc, scale	A Bradford continuous random variable.
burr	c, d, loc, scale	A Burr (Type III) continuous random variable.
burr12	c, d, loc, scale	A Burr (Type XII) continuous random variable.
cauchy	loc, scale	A Cauchy continuous random variable.
chi	df, loc, scale	A chi continuous random variable.
chi2	df, loc, scale	A chi-squared continuous random variable.
cosine	loc, scale	A cosine continuous random variable.
crystalball	beta, m, loc, scale	Crystalball distribution
dgamma	a, loc, scale	A double gamma continuous random variable.
dpareto_lognorm	u, s, a, b, loc, scale	A double Pareto lognormal continuous random variable.
dweibull	c, loc, scale	A double Weibull continuous random variable.
erlang	a, loc, scale	An Erlang continuous random variable.
expon	loc, scale	An exponential continuous random variable.
exponnorm	K, loc, scale	An exponentially modified Normal continuous random variable.
exponweib	a, c, loc, scale	An exponentiated Weibull continuous random variable.
exponpow	b, loc, scale	An exponential power continuous random variable.
f	dfn, dfd, loc, scale	An F continuous random variable.
fatiguelife	c, loc, scale	A fatigue-life (Birnbaum-Saunders) continuous random variable.
fisk	c, loc, scale	A Fisk continuous random variable.
foldcauchy	c, loc, scale	A folded Cauchy continuous random variable.
foldnorm	c, loc, scale	A folded normal continuous random variable.
genlogistic	c, loc, scale	A generalized logistic continuous random variable.
gennorm	beta, loc, scale	A generalized normal continuous random variable.
genpareto	c, loc, scale	A generalized Pareto continuous random variable.
genexpon	a, b, c, loc	A generalized exponential continuous random variable.
genextreme	c, loc, scale	A generalized extreme value continuous random variable.
gausshyper	a, b,c, z, loc, scale	A Gauss hypergeometric continuous random variable.
gamma	a, loc, scale	A gamma continuous random variable.
gengamma	a, c, loc, scale	A generalized gamma continuous random variable.
genhalflogistic	c, loc, scale	A generalized half-logistic continuous random variable.
genhyperbolic	p, a, b, loc, scale	A generalized hyperbolic continuous random variable.
geninvgauss	p, b, loc, scale	A Generalized Inverse Gaussian continuous random variable.
gibrat	loc, scale	A Gibrat continuous random variable.
gompertz	c, loc, scale	A Gompertz (or truncated Gumbel) continuous random variable.
gumbel_r	loc, scale	A right-skewed Gumbel continuous random variable.
gumbel_l	loc, scale	A left-skewed Gumbel continuous random variable.
halfcauchy	loc, scale	A Half-Cauchy continuous random variable.
halflogistic	loc, scale	A half-logistic continuous random variable.
halfnorm	loc, scale	A half-normal continuous random variable.
halfgennorm	beta, loc, scale	The upper half of a generalized normal continuous random variable.
hypsecant	loc, scale	A hyperbolic secant continuous random variable.
invgamma	a, loc, scale	An inverted gamma continuous random variable.
invgauss	mu, loc, scale	An inverse Gaussian continuous random variable.
invweibull	c, loc, scale	An inverted Weibull continuous random variable.
irwinhall	n, loc, scale	An Irwin-Hall (Uniform Sum) continuous random variable.
jf_skew_t	a, b, loc, scale	Jones and Faddy skew-t distribution.
johnsonsb	a, b, loc, scale	A Johnson SB continuous random variable.
johnsonsu	a, b, loc, scale	A Johnson SU continuous random variable.
kappa4	h, k, loc, scale	Kappa 4 parameter distribution.
kappa3	a, loc, scale	Kappa 3 parameter distribution.
ksone	n, loc, scale	Kolmogorov-Smirnov one-sided test statistic distribution.
kstwo	n, loc, scale	Kolmogorov-Smirnov two-sided test statistic distribution.
kstwobign	loc, scale	Limiting distribution of scaled Kolmogorov-Smirnov two-sided test statistic.
landau	loc, scale	A Landau continuous random variable.
laplace	loc, scale	A Laplace continuous random variable.
laplace_asymmetric	kappa, loc, scale	An asymmetric Laplace continuous random variable.
levy	loc, scale	A Levy continuous random variable.
levy_l	loc, scale	A left-skewed Levy continuous random variable.
levy_stable	alpha, beta, loc, scale	A Levy-stable continuous random variable.
logistic	loc, scale	A logistic (or Sech-squared) continuous random variable.
loggamma	c, loc, scale	A log gamma continuous random variable.
loglaplace	c, loc, scale	A log-Laplace continuous random variable.
lognorm	s, loc, scale	A lognormal continuous random variable.
loguniform	a, b, loc, scale	A loguniform or reciprocal continuous random variable.
lomax	c, loc, scale	A Lomax (Pareto of the second kind) continuous random variable.
maxwell	loc, scale	A Maxwell continuous random variable.
mielke	k, s, loc, scale	A Mielke Beta-Kappa / Dagum continuous random variable.
moyal	loc, scale	A Moyal continuous random variable.
nakagami	nu, loc, scale	A Nakagami continuous random variable.
ncx2	df, nc, loc, scale	A non-central chi-squared continuous random variable.
ncf	dfn, dfd, nc, loc, scale	A non-central F distribution continuous random variable.
nct	df, nc, loc, scale	A non-central Student’s t continuous random variable.
norm	loc, scale	A normal continuous random variable.
norminvgauss	a, b, loc, scale	A Normal Inverse Gaussian continuous random variable.
pareto	b, loc, scale	A Pareto continuous random variable.
pearson3	skew, loc, scale	A pearson type III continuous random variable.
powerlaw	a, loc, scale	A power-function continuous random variable.
powerlognorm	c, s, loc, scale	A power log-normal continuous random variable.
powernorm	c, loc, scale	A power normal continuous random variable.
rdist	c, loc, scale	An R-distributed (symmetric beta) continuous random variable.
rayleigh	loc, scale	A Rayleigh continuous random variable.
rel_breitwigner	rho, loc, scale	A relativistic Breit-Wigner random variable.
rice	b, loc, scale	A Rice continuous random variable.
recipinvgauss	mu, loc, scale	A reciprocal inverse Gaussian continuous random variable.
semicircular	loc, scale	A semicircular continuous random variable.
skewcauchy	a, loc, scale	A skewed Cauchy random variable.
skewnorm	a, loc, scale	A skew-normal random variable.
studentized_range	k, df, loc, scale	A studentized range continuous random variable.
t	df, loc, scale	A Student’s t continuous random variable.
trapezoid	c, d, loc, scale	A trapezoidal continuous random variable.
triang	c, loc, scale	A triangular continuous random variable.
truncexpon	b, loc, scale	A truncated exponential continuous random variable.
truncnorm	a, b, loc, scale	A truncated normal continuous random variable.
truncpareto	b, c, loc, scale	An upper truncated Pareto continuous random variable.
truncweibull_min	c, a, b, loc, scale	A doubly truncated Weibull minimum continuous random variable.
tukeylambda	lam, loc, scale	A Tukey-Lamdba continuous random variable.
uniform	loc, scale	A uniform continuous random variable.
vonmises	kappa, loc	A Von Mises continuous random variable.
vonmises_line	kappa, loc	A Von Mises continuous random variable.
wald	loc, scale	A Wald continuous random variable.
weibull_min	c, loc, scale	Weibull minimum continuous random variable.
weibull_max	c, loc, scale	Weibull maximum continuous random variable.
wrapcauchy	c, loc, scale	A wrapped Cauchy continuous random variable.