lognormal_series: Series of independent Lognormal components (closed form)

In dist.structure: Structured Random Variables for Reliability System Distributions

Series of independent Lognormal components (closed form)

Description

Constructs a dist_structure for a series system whose components are independent Lognormals. Closed-form surv is the product of per-component upper-tail probabilities; cdf is 1 - surv; sampler generates m independent Lognormals and takes the min.

Usage

lognormal_series(meanlogs, sdlogs)

## S3 method for class 'lognormal_series'
surv(x, ...)

## S3 method for class 'lognormal_series'
sampler(x, ...)

Arguments

meanlogs	Numeric vector of length m: per-component meanlog parameters.
sdlogs	Positive numeric vector of length m: per-component sdlog parameters.
x	A lognormal_series object.
...	Ignored.

Value

lognormal_series() returns an object of class c("lognormal_series", "series_dist", "coherent_dist", "dist_structure", "univariate_dist", "continuous_dist", "dist").

The associated S3 methods return:

• surv(): a closure ⁠function(t, ...)⁠.

• cdf() is derived via the dist_structure default and returns a closure ⁠function(t, ...)⁠ equal to 1 - surv(x)(t).

• sampler(): a closure ⁠function(n, ...)⁠ returning n random variates from the system lifetime distribution.

Examples

sys <- lognormal_series(meanlogs = c(0, 1), sdlogs = c(1, 0.5))
algebraic.dist::surv(sys)(1)

dist.structure documentation built on May 13, 2026, 1:07 a.m.