Though robustness analysis does elucidate the effects of perturbations of one parameter, it cannot show any non-linear effects which occur when two or more are adjusted simultaneously. A Global Sensitivity Analysis technique is needed to identify such effects, and to give an indication of the parameters which have the greatest influence on the simulation output. This technique uses the method described by Read et al in their paper reference in the tutorial, which uses a latin-hypercube design to sample the parameter space. Ranges are set for each parameter, and all parameter values perturbed concurrently. This method creates the parameter value sets with which simulations should be run. This is output as a CSV file. For each set of parameters, the simulation should be run for the number of times identified in Aleatory Analysis. Once this has been completed, the set of remaining methods within spartan can be used to analyse the results. Note: To run this, you will require the lhs library. Version 3.1 adds returning the sample as a object, should this be easier to process than reading back in a file
lhc_generate_lhc_sample(FILEPATH, PARAMETERS, NUMSAMPLES, PMIN, PMAX,
ALGORITHM, PINC = NULL, write_csv = TRUE)Directory where the parameter samples should be output to
Array containing the names of the parameters of which parameter samples will be generated
The number of parameter subsets to generate
Array containing the minimum value that should be used for each parameter. Sets a lower bound on sampling space
Array containing the maximum value that should be used for each parameter. Sets an upper bound on sampling space
Choice of algorithm to use to generate the hypercube. Can be set to either 'normal' or 'optimum'. Beware optimum can take a long time to generate an optimised parameter set (more than 24 hours in some circumstances)
Array containing the increment value that should be applied for each parameter. For example, a parameter could have a minimum value of 10, and maximum value of 100, and be incremented by 10. Added after user request on Github
Whether the sample should be output to a CSV file or not. Introduced with spartan database link. Defaults to TRUE
LHC generated parameter sets