ML4EO ‐ MVP - jejjohnson/research_journal_v2 GitHub Wiki

Interpolation

Ideas

  • Patch-Based GPR
  • EOF Priors with Probabilistic PCA
  • GP Priors with Conditional Flows
  • L2 Data Priors with Conditional Flows
  • L3 Data Priors with Conditional Flows
  • Deep Equilibrium Models
  • Dynamical Emulators

Gaussian Process

The upside of interpolation methods is that they are physically consistent, i.e., things that are closer should be similar. The downside of this is that it isn’t causally consistent. Especially with respect to time. In addition, coordinate-based methods have trouble capturing multiscale activities because this requires many many samples which becomes expensive very fast.


EOF

We use a the classic DINEOF algorithm to perform gap-filling on missing data.


Resources


Missing Data Challenges


Baseline

  • Classic DINEOF algorithm
  • Iterative Updates
  • Scalable Iterative Eigenvalue Decomposition
  • Covariance Matrix Regularizers (Laplacian)
  • Equilibrium Model Formulation

Examples

  • Simplest Example (no fast eigenvalue solver) - tieof
  • Simple Example (no fast eigenvalue solver) - PyPlume

Stategy

  1. Parameter Estimation w/ Probabilistic PCA
  2. State Estimation w/ PPCA AutoEncoder
  3. Latent State Estimation w/ PPCA Decoder

Field Initialization

  • Mean
  • Partial Convolutions - Astropy

Weight Initialization

  • scikit-learn - PCA

Tutorials - GP

  • Locality - K-Nearest Neighbours (Unstructured, Semantic) vs Radius Neighbours (Structured)
  • Weighted Distances - Inverse, RBF
  • Scale - Algorithm (KD-Tree, Ball-Tree, R-Tree, PyNNDescent)
  • Scale - Hardware (Parallel CPU, GPU)
  • Kernel Density Estimation
  • GPs from scratch
  • GPs with a PPL
  • Scale - Algorithm (Subset, Approximate Kernel - inversion, logdet), Hardware (GPU)
  • Reduced Points - Sparse GP (Fixed vs Variable)
  • Locality at Scale - Patches - Split-Apply-Combine (Patch Size, Stride, DataLoader, Weighted Stitching)
  • MegaScale Patching from the cloud
  • Patches - MegaScale Combination with memory issues
  • Patches vs Neighbours
  • Patch-Based - GP & SparseGP Interpolation
  • Linear Regression
  • Basis Function - Polynomial, RBF, Spherical Harmonics
  • Neural Fields

Tutorials

In this tutorial, we will look at feature extractors as a way to fill in the gaps. we will start with the simplest method: PCA/EOFs/POD which is a parametric linear method. We will apply this method to missing data. Afterwards, we will enhance this method by using more non-linear representations.


Tutorials - Dynamical Models

In this tutorial, we will work with dynamical models. We will look at the anatomy of a state space model to understand all of the pieces. Then we will look at the Dynamic Mode Decomposition as the simplest start. Then we will look at some more non-linear structures taking inspiration from Numerical methods.

  • Anatomy of a State Space Model - Initial Condition, Dynamical Model, Measurement Model
  • DMD From Scratch - Video
  • Scaling -> Randomized SVD, Scalable Eigenvalue Decomposition
  • DMD as a Minimization Problem - OptDMD
  • DMD w/ Missing Observations
  • Markovian Gaussian Process
  • Conditional Flows