Skip to content

jonghyunharrylee/pyPCGA

Repository files navigation

pyPCGA

Python library for Principal Component Geostatistical Approach

version 0.1

updates

  • Exact preconditioner construction (inverse of cokriging/saddle-point matrix) using generalized eigendecomposition [Lee et al., WRR 2016, Saibaba et al, NLAA 2016]
  • Fast hyperparameter tuning and predictive model validation using cR/Q2 criteria [Kitanidis, Math Geol 1991] ([Lee et al., 2021 in preparation])
  • Fast posterior variance/std computation using exact preconditioner

version 0.2 will include

  • automatic covariance model parameter calibration with nearshore application example
  • link with FMM and HMatrix to support unstructured grids

Installation

python -m pip install git+https://github.com/jonghyunharrylee/pyPCGA.git

Courses

Example Notebooks

1D linear inversion example below will be helpful to understand how pyPCGA can be implemented. Please check Google Colab examples.

Credits

pyPCGA is based on Lee et al. [2016] and currently used for Stanford-USACE ERDC project led by EF Darve and PK Kitanidis and NSF EPSCoR `Ike Wai project.

Code contributors include:

  • Jonghyun Harry Lee
  • Matthew Farthing
  • Ty Hesser (STWAVE example)
  • Antoine COLLET

FFT-based matvec code is adapted from Arvind Saibaba's work (https://github.com/arvindks/kle).

FMM-based code (https://arxiv.org/abs/1903.02153) will be incorporated in version 0.2

References

  • J Lee, H Yoon, PK Kitanidis, CJ Werth, AJ Valocchi, "Scalable subsurface inverse modeling of huge data sets with an application to tracer concentration breakthrough data from magnetic resonance imaging", Water Resources Research 52 (7), 5213-5231

  • AK Saibaba, J Lee, PK Kitanidis, Randomized algorithms for generalized Hermitian eigenvalue problems with application to computing Karhunen–Loève expansion, Numerical Linear Algebra with Applications 23 (2), 314-339

  • J Lee, PK Kitanidis, "Large‐scale hydraulic tomography and joint inversion of head and tracer data using the Principal Component Geostatistical Approach (PCGA)", WRR 50 (7), 5410-5427

  • PK Kitanidis, J Lee, Principal Component Geostatistical Approach for large‐dimensional inverse problems, WRR 50 (7), 5428-5443

Applications

  • T. Kadeethum, D. O'Malley, JN Fuhg, Y. Choi, J. Lee, HS Viswanathan and N. Bouklas, A framework for data-driven solution and parameter estimation of PDEs using conditional generative adversarial networks, Nature Computational Science, 819–829, 2021

  • J Lee, H Ghorbanidehno, M Farthing, T. Hesser, EF Darve, and PK Kitanidis, Riverine bathymetry imaging with indirect observations, Water Resources Research, 54(5): 3704-3727, 2018

  • J Lee, A Kokkinaki, PK Kitanidis, Fast large-scale joint inversion for deep aquifer characterization using pressure and heat tracer measurements, Transport in Porous Media, 123(3): 533-543, 2018

  • PK Kang, J Lee, X Fu, S Lee, PK Kitanidis, J Ruben, Improved Characterization of Heterogeneous Permeability in Saline Aquifers from Transient Pressure Data during Freshwater Injection, Water Resources Research, 53(5): 4444-458, 2017

  • S. Fakhreddine, J Lee, PK Kitanidis, S Fendorf, M Rolle, Imaging Geochemical Heterogeneities Using Inverse Reactive Transport Modeling: an Example Relevant for Characterizing Arsenic Mobilization and Distribution, Advances in Water Resources, 88: 186-197, 2016