Variables

The following section will discuss what is required for each variable when using the UQPCE input yaml file. Refer to the variables section for more information on the different distributions.

Supported Distributions

Class	Distribution	Required Parameters	Optional Parameters
ContinuousVariable	continuous	pdf, interval_low, interval_high
EpistemicVariable	epistemic	interval_low, interval_high
NormalVariable	normal	mean, stdev
UniformVariable	uniform	interval_low, interval_high
BetaVariable	beta	alpha, beta	interval_low (default = 0), interval_high (default = 1)
ExponentialVariable	exponential	lambda	interval_low (default = 0)
GammaVariable	gamma	alpha, theta	interval_low (default = 0)
LognormalVariable	lognormal	mean, stdev	interval_low (default = 0)
DiscreteVariable	discrete	pdf, interval_low, interval_high
DiscreteEpistemicVariable	discrete_uniform	interval_low, interval_high
NegativeBinomialVariable	negative_binomial	r, p	interval_low (default = 0)
DiscreteUniformVariable	discrete_uniform	interval_low, interval_high
PoissonVariable	poisson	lambda	interval_low (default = 0)
HypergeometricVariable	hypergeometric	M, n, N	interval_low (default = 0)

 

Variable Parameters

Name	Type	Description
name	str	The name for the physical meaning of the variable (default = x{number})
distribution	str	a string value for the chosen distribution; can be any of the types in the above Distribution column
pdf	str	The PDF for a user-input variable; must follow SymPy notation
mean	float	This option is the mean of a NormalVariable and the mean of the natural logarithm for the LognormalVariable
stdev	float	This option is the standard deviation of a NormalVariable and the mean of the natural logarithm for the LognormalVariable
interval_low	float	This option is the lower interval on which the data lies
interval_high	float	This option is the upper interval on which the data lies
alpha	float	The \(\alpha\) parameter of the BetaVariable and the GammaVariable
beta	float	The \(\beta\) parameter of the BetaVariable
theta	float	The \(\theta\) parameter of the GammaVariable
lambda	float	The \(\lambda\) parameter of the ExponentialVariable and PoissonVariable
r	float	The \(r\) parameter of the NegativeBinomialVariable
p	float	The \(p\) parameter of the NeativeBinomialVariable
M	float	The \(M\) parameter of the HypergeometricVariable
n	float	The \(n\) parameter of the HypergeometricVariable
N	float	The \(N\) parameter of the HypergeometricVariable

Note

The pdf parameter must be in the SymPy notation with x as the variable in the PDF.

sqrt(2 * pi) = \(\sqrt{2\pi}\)

exp(-x) = \(e^{-x}\)

Note

YAML files are sensitive to spacing and tabs. Ensure that there are no trailing spaces in the lines. See the PyYAML documentation for more information.