Get the parameter layout for a system

Returns the mapping from global (flat) parameter indices to per-component parameter indices, enabling the series system to distribute a single parameter vector across its components.

Usage

param_layout(x, ...)

# S3 method for class 'dfr_dist_series'
param_layout(x, ...)

Arguments

x

A system object (e.g., dfr_dist_series).

...

Additional arguments passed to methods.

Value

A list of integer vectors, one per component, containing global parameter indices.

Details

Parameters across all components are stored as a single concatenated vector \(\theta = (\theta_1, \ldots, \theta_m)\). The layout maps global indices back to each component. For example, with:

• Component 1: Weibull (shape, scale) — 2 parameters

• Component 2: Exponential (rate) — 1 parameter

• Component 3: Gompertz (a, b) — 2 parameters

the layout is list(1:2, 3, 4:5), so the global parameter vector c(shape1, scale1, rate2, a3, b3) gets sliced as par[1:2] for component 1, par[3] for component 2, and par[4:5] for component 3.

This design enables standard optimizers to work on a flat vector while the series system internally distributes parameters to the correct components.

Methods (by class)

• param_layout(dfr_dist_series): Parameter index mapping for a series system.

See also

component to extract a component with its parameters, params to get the full parameter vector, dfr_dist_series for the constructor

Other system introspection: component(), component_hazard(), ncomponents(), sample_components()

Examples

# \donttest{
library(flexhaz)

sys <- dfr_dist_series(list(
    dfr_weibull(shape = 2, scale = 100),
    dfr_exponential(0.05),
    dfr_gompertz(a = 0.01, b = 0.1)
))
param_layout(sys)
#> [[1]]
#> [1] 1 2
#> 
#> [[2]]
#> [1] 3
#> 
#> [[3]]
#> [1] 4 5
#> 
# list(1:2, 3, 4:5)
# }