sa_analyze
Analyze saved simulation variable results from sensitivity analysis designs. Computes Sobol indices or elementary effects and returns fit quality and factor effect tables.
Instructions
Analyse the design results for one saved variable with LSD's R package LSDsensitivity. metamodel 'kriging' (default for lhs, random and nolh designs) or 'polynomial' fits a meta-model and computes its Sobol decomposition: returns the fit quality (Q2 for kriging, R2 for polynomial) and a table with direct effects and interactions per factor. For a design made with method 'ee' the analysis is elementary effects (metamodel 'ee', chosen automatically): returns per factor mu, mu_star, sigma, se and p_value (parameters scaled to [0, 1]; mu_star is the overall effect, sigma non-linear or interaction effects, p_value tests mu_star = 0), sorted by mu_star. Kriging or polynomial on an ee design, or ee on another design, is an error. For an ee design made in LSD's own interface (no design file) pass metamodel='ee' with its levels and jump. ini_drop drops initial time steps, n_keep keeps that many (-1 = all). The response is the mean of the variable over the kept steps, averaged over runs. Variables whose name starts with '_' work; with several instances only the first instance is analysed. ini_drop must be below MAX_STEP and ini_drop + n_keep at most MAX_STEP. r_seed seeds R's random numbers, so identical calls give identical results. A warning is added when a meta-model fit is below 0.5. The polynomial meta-model fails when a design point has a negative mean response (LSD weights points by mean/SD) and needs at least two factors; use kriging then. Kriging can fail numerically when design points nearly coincide (the message says so; try polynomial). Needs Rscript and LSDsensitivity; says so if they are missing.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| jump | No | ||
| model | Yes | ||
| config | Yes | ||
| levels | No | ||
| n_keep | No | ||
| r_seed | No | ||
| ini_drop | No | ||
| variable | Yes | ||
| metamodel | No |