Specific Meaning of workdirs

[mlochhead]

I am running R2D for 12 structures in a region. In each of the responses (tmp.SimCenter > Results > Buildings > 1), I am getting five working directories. In the documentation, it says that the UQ engine creates the working directories for each realization of structural response. I'm assuming the number of workdirs corresponds to the number of samples I put in the UQ tab in the user interface.

However, can you clarify how the ground motions are selected for these realizations? I have an EventGrid with 10 ground motion time histories for each site, and I am using NearestNeighbor using 5 samples and 4 neighbors (like many of the examples). In each working directory, is it selecting just one ground motion time history to use? Thus, if I specify 5 samples in the UQ tab and 10 samples for the NearestNeighbor, would only five of those ground motions actually be used in analysis? Thanks for the clarification.

[fmk]

Yes only 5, the number specified in the UQ tab,  would be used.

[Obect1980]

The selection of ground motion time histories for each realization is determined by the UQ methodology you've chosen and the settings you've specified. In your case, you mentioned using NearestNeighbor with 5 samples and 4 neighbors. If you've specified 5 samples in the UQ tab, this corresponds to the number of different sets of input parameters that will be sampled. If you're using NearestNeighbor with 4 neighbors, this means that for each sampled set of parameters, the code will select the nearest 4 ground motion time histories from your EventGrid based on some similarity metric. These 4 selected ground motion time histories will then be used for that particular realization of structural response. mcdvoice