Sensitivity threshold value (Fast)

[monbiola]

Hi,

I would like to know how the sensitivity threshold value is calculated (red dotted line in the graph https://spotpy.readthedocs.io/en/latest/Sensitivity_analysis_with_FAST/). From which formula or bibliographic reference is it derived ?

Thanks !

[thouska]

Hi @monbiola,
there is no generally accepted way to calculate a sensitivity threshold of the FAST sensitivity index. The visual differentiation in the spotpy analyser and the example you referenced is a a simply a user defined number of parameters that are colored different. The keyword in the spotpy.analyser.plot_fast_sensitivity is number_of_sensitiv_pars. So, if the keyword is set to, e.g. 3, the three most sensitive parameters would get a blue color and the red line would be plotted at the sensitivity index of the 3rd most sensitive parameter.