# Infection Dynamic Model (Global Sensitivity Analysis - GUI)

This page shows how to perform Global Sensitivity Analysis of the Infection Dynamic Model in the Graphical User interface of * COSSAN-X*.

## Contents

# Analysis

In order to perform Sensitivity Analysis it is necessary to start from a model. In this example the sensitivity analysis can be started clicking on the green bottom on the right top corner of the Physical Model defined here.

## Global Sensitivity Analysis

First at all the sensitivity analysis must be selected from the first page of the wizard.

Then the kind of sensitivity analysis should be selected and the output factor of interest. In our case there is only 1 output provide by the model (Y).

### Random Design Balance

In the next page of the wizard, it is possible to select the method used to calculate the sensitivity measures and the uncertainty factors considered in the sensitivity analysis. By default all uncertainty factors defined in the model are selected. The user can decide to change the order of these input factors or calculate the sensitivity analysis for a subset of the uncertainty factors.

### Sobol' indices

The first order Sobol' indices and the Total indices can be estimated by means of the Saltelli' method implemented in the method SobolIndices@Sensitivity. This algorithm can be selection choosing the option Sobol' indices.

This method requires a Simulation object to generate samples for the global sensitivity analysis. This simulation object is created by the Uncertainty Quantification (wizard). For instance, a Monte Carlo analysis can be used to generate the samples. Alternatively, other quasi-Monte Carlo method can be used.

Finally pressing finish button the global sensitivity analysis is starting