2D SWE: default LSPG¶
ROM technique: basic LSPG
problem: 2D shallow water equations (SWE)
Prerequisites¶
A valid build of the tutorials, see here,
The following env variables MUST be set:
export REPOSRC=<full-path-to-the-pressio-tutorials-source-repo>/end-to-end-roms export BUILDDIR=<full-path-to-where-you-built-the-tutorials>
To run the demo scripts below, you MUST be inside the correct directory:
cd $BUILDDIR/end-to-end-roms/2d_swe_lspg_default
Workflow File¶
The workflow file for this demo is shown below for exposition purposes, but it is automatically copied to the build directory, so you don’t need to do anything:
1problem: 2d_swe
2
3parameterSpace:
4 names: ['coriolis', 'pulsemag', 'gravity']
5 trainPoints:
6 0: [-1.0, 0.125, 9.8]
7 1: [ 0.0, 0.125, 9.8]
8 testPoints:
9 0: [-0.5, 0.125, 9.8]
10
11fom:
12 meshSize: [65, 65]
13 inviscidFluxReconstruction: "Weno3"
14 odeScheme: "BDF1"
15 timeStepSize: 0.01
16 nonlinearSolverName: NewtonRaphson
17 nonlinearSolverTolerance: 1e-6
18 train:
19 finalTime: 5.0
20 stateSamplingFreq: 10
21 test:
22 finalTime: 5.0
23 stateSamplingFreq: 10
24
25offlineRom:
26 pod:
27 stateData:
28 useTrainingRuns: all
29
30onlineRom:
31 algorithm: defaultLspg
32 nonlinearSolverName: GaussNewton
33 nonlinearSolverTolerance: 1e-6
34 podTruncation:
35 energyBased: [99.999, 99.99999]
Step 1: execute FOMs¶
# from within $BUILDDIR/end-to-end-roms/2d_swe_lspg_default
python3 $REPOSRC/wf_foms.py --wf wf.yaml
Warning
This might take a few mins to run, be patient!
At the end, doing tree -L 1 . should produce:
.
├── CMakeFiles
├── Makefile
├── cmake_install.cmake
├── fom_mesh
├── fom_test_runid_0
├── fom_train_runid_0
├── fom_train_runid_1
├── plot.py
└── wf.yaml
Step 2: offline rom¶
# from within $BUILDDIR/end-to-end-roms/2d_swe_lspg_default
python3 $REPOSRC/wf_offline_rom.py --wf wf.yaml
The offline rom takes care of using the FOM training data to compute the POD modes, and creates all data into an “offline_rom” subdirectory:
./offline_rom/
├── pod_input.yaml
├── state_left_singular_vectors.bin
├── state_singular_values.txt
└── state_snapshots.bin
Step 3: lspg rom¶
# from within $BUILDDIR/end-to-end-roms/2d_swe_lspg_default
python3 $REPOSRC/wf_lspg.py --wf wf.yaml
At the end, you should have the following directory structure:
.
├── CMakeFiles
├── Makefile
├── cmake_install.cmake
├── default_lspg_truncation_energybased_99.99999_runid_0
├── default_lspg_truncation_energybased_99.999_runid_0
├── fom_mesh
├── fom_test_runid_0
├── fom_train_runid_0
├── fom_train_runid_1
├── offline_rom
├── plot.py
└── wf.yaml
Step 4: process results¶
# from within $BUILDDIR/end-to-end-roms/2d_swe_lspg_default
python3 $REPOSRC/wf_reconstruct_on_full_mesh.py
python3 plot.py
