gpd-sensitivity-analysis

Computes parameter sensitivity coefficients and ranks uncertainty contributions in physics calculations.

Updated Mar 18, 2026
One-click install
npx skills add https://github.com/MichaelsEngineering/sentinel-multiscale-field-dynamics --skill gpd-sensitivity-analysis-michaelsengineering
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: gpd-sensitivity-analysis
Source: https://github.com/MichaelsEngineering/sentinel-multiscale-field-dynamics/tree/main/.agents/skills/gpd-sensitivity-analysis
Command: npx skills add https://github.com/MichaelsEngineering/sentinel-multiscale-field-dynamics --skill gpd-sensitivity-analysis-michaelsengineering

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires numpy, sympy.

What problem does it solve? Physics models often depend on many parameters, but results are typically dominated by only a few. Without sensitivity analysis, error bars are numbers without actionable meaning, and effort may be wasted improving parameters that barely affect the output. This Skill identifies which input parameters most strongly affect a target quantity and where precision-improvement effort should be directed. ## Core Features & Use Cases - Sensitivity Coefficient Computation: Calculates dimensionless sensitivity coefficients S_i = (df/dp_i)(p_i/f) via analytical (SymPy symbolic differentiation) or numerical (central finite differences) methods. - Parameter Ranking & Uncertainty Budget: Ranks parameters by contribution to output uncertainty, identifies stiff and null directions in parameter space, and flags divergent sensitivities indicating critical points or ill-conditioned formulations. - Approximation Sensitivity: Estimates systematic errors from active approximations (perturbation theory, continuum limits, truncations) as controlling parameters approach validity boundaries. - Use Case: A researcher computing a predicted energy value of 3.7 +/- 0.2 eV uses this Skill to discover that 90% of the uncertainty comes from the coupling constant, directing measurement effort where it has the greatest impact. ## Quick Start Ask the AI to run a sensitivity analysis on a target quantity, for example: analyze which parameters most affect the turbulence energy output and rank them by uncertainty contribution.

Frequently Asked Questions about gpd-sensitivity-analysis

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I perform sensitivity analysis on physics model parameters?▼

Identify the target quantity and its input parameters, then compute dimensionless sensitivity coefficients S_i = (df/dp_i)(p_i/f) using analytical derivatives for closed-form expressions or central finite differences for numerical pipelines. Rank parameters by their contribution to output uncertainty.

What is the difference between local sensitivity, Morris method, and Sobol indices?▼

Local sensitivity uses partial derivatives around a nominal point and costs N+1 evaluations. Morris screening handles many parameters cheaply to identify important ones. Sobol indices give full nonlinear decomposition including interactions but require 1000+ evaluations, suiting fewer than 5 parameters.

When should I use analytical versus numerical sensitivity methods?▼

Use analytical symbolic differentiation when the target function has a closed-form expression, since it gives exact derivatives at zero computational cost. Use numerical finite differences when the computation is a multi-step pipeline without a single symbolic form, or combine both per parameter.

What does a divergent sensitivity coefficient indicate?▼

A sensitivity coefficient exceeding roughly 100 typically signals a critical point, resonance, cancellation between large terms, or an ill-conditioned formulation. Such cases need non-perturbative treatment or reformulation near the divergence rather than standard error propagation.

Why do finite-difference sensitivity calculations give inconsistent results?▼

Inconsistent derivatives at different step sizes indicate numerical instability. Reduce the perturbation fraction, switch to analytical derivatives where possible, or flag the parameter for special treatment. Verify the dependency chain if all sensitivities appear near zero.