Input moment and sampling

UQ with UQLab Community Q&A and How To
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Hi

Thanks for your interest in UQLab. You have many questions in a single post. It would be better to be more specific on one topic at a time.

Some answers though:

  1. According to the general framework for uncertainty quantification, you have to assume some input distributions, based on your existing data or prior knowledge.
    You can find more detailed information here.
  2. Regarding your plot of the inputs for the truss problem: this is only a plot from say 1,000 samples, so the plotted histograms are not accurate. Yet in the calculations, the Gumbel distributions defined in the INPUT object are used.
  3. Regarding copulas, the best way to start is to read the relevant section of the Input manual, and then refer to the references therein. Regarding the inference of copulas from existing data, you can look at the Inference manual.

Good luck with UQ!
Best regards
Bruno