Qualitative inputs

UQ with UQLab Community Q&A and How To
1

Hi everyone,

I was wondering if there were any tools in UQLab in dealing with qualitative (rather than quantitative) inputs for a engineering system.

Let’s say we have a system with inputs x1 and x2. x1 is a quantitative input with certain distribution, while x2 is a qualitative input such as the type of simulation algorithm, whether to include some modeling features or not, or ordinal variables.

In this case, it that possible to do sensitivity analysis in order to determine whether x1 or x2 has more impact on the output of the system?

Thanks a lot in advance!

Best,

Hongzhou

2

Hi @HZhang,

No, unfortunately UQLab does not support categorical input variables yet.

So you cannot use UQLab directly to do sensitivity analysis in such a case. However you can probably build separate metamodels for each possible combination of categorical variables, and then aggregate the information in some way. (Not sure how exactly, but I have the impression it should be possible…)

If you find a way to deal with this interesting problem, please let us know how! :slight_smile:

3

Thank you very much @nluethen for the reply. I will let you know once I find how to deal with it. :blush:

4

Hello,

Is there any update on how to use qualitative inputs into sensitivity analyisis? I want to apply a Sobol sensitivity analysis but I have a mixed type of inputs both continous and categorical ones.

I’ve encounter that UQLab doesn’t support categorical variables right now. But is there a way to overcome this?

I’ve been looking at the posts in the community but couldn’t find one that helps.

Best regards
Erhan.