Tutorial 3: BSS-ANOVA¶
This tutorial covers the BSS-ANOVA surrogate modeling method. The Bayesian Smoothing Spline ANOVA (BSS-ANOVA) is essentially a Bayesian version of ACOSSO (Reich et al. 2009). It is Gaussian Process (GP) model with a non-conventional covariance function that borrows its form from SS-ANOVA. It tackles the high dimensionality (of inputs) on two fronts: (1) variable selection to eliminate uninformative variables from the model and (2) restricting the level of interactions involved among the variables in the model. This is done through a fully Bayesian approach which can also allow for categorical input variables with relative ease. Since it is closely related to ACOSSO, it generally works well in similar settings as ACOSSO. The BSS-ANOVA procedure also allows for categorical inputs (Storlie et al. 2013). In this current implementation, BSS-ANOVA is more computationally intensive than ACOSSO, so ACOSSO is preferred for faster surrogate generation.
This tutorial uses the same flowsheet and sample setup as the ALAMO tutorial in Section Tutorial 1: ALAMO.
The FOQUS file for this tutorial is Surrogate_Tutorial_1.foqus, and
this file is located in: examples/tutorial_files/Surrogates
Note
The examples/ directory refers to the location where the FOQUS examples were installed, as described in Install FOQUS Examples.
The statistics software “R” is also required to use ACOSSO and BSS-ANOVA. Before starting this tutorial, you will need to install R version 3.1 or later (see http://cran.r-project.org/).
Set the path to the RScript executable.
Click the Settings button from the Home window.
Change the RScript path if necessary. The Browse button opens a file browser that can be used to set the path.
Complete the ALAMO tutorial in Section Tutorial 1: ALAMO through Step 32, load the FOQUS session saved after completing the ALAMO tutorial, or load the “Surrogate_Tutorial_1.foqus” file from the examples/tutorial_files/Surrogates folder.
Click the Surrogates button from the Home window (Figure BSS-ANOVA Session Set Up).
Select “BSS-ANOVA” in the Tool drop-down list.
Select the Method Settings tab.
Set “Data Filter” to “Initial.”
Set “Use Flowsheet Data” to “Yes.”
Set “FOQUS Model (for UQ)” to “bssanova_tutorial_uq.py.”
Set “FOQUS Model (for Flowsheet)” to “bssanova_tutorial_fs.py.”
Click the Run icon (Figure BSS-ANOVA Session Set Up).
BSS-ANOVA Session Set Up¶
The execution window will automatically display. While BSS-ANOVA is running, the execution window may show warnings, but this is normal.
When the run completes, a UQ driver file is created, allowing the BSS-ANOVA surrogate to be used as a user-defined response surface in UQ analyses. (See Section Tutorial 4: Surrogates with UQ Tools.)
BSS-ANOVA also produces a flowsheet plugin.