microplex

Microdata synthesis and reweighting using normalizing flows.

Overview

microplex creates rich, calibrated microdata through:

• Conditional relationships: Generate target variables given demographics
• Zero-inflated distributions: Handle variables that are 0 for many observations
• Joint correlations: Preserve relationships between target variables
• Hierarchical structures: Keep household/firm compositions intact

Installation

pip install microplex

Quick Start

from microplex import Synthesizer
import pandas as pd

# Load training data with known target variables
training_data = pd.read_csv("survey_with_income.csv")

# Initialize synthesizer
synth = Synthesizer(
    target_vars=["income", "expenditure", "savings"],
    condition_vars=["age", "education", "region"],
)

# Fit on training data
synth.fit(training_data, weight_col="weight", epochs=100)

# Generate synthetic targets for new demographics
new_demographics = pd.read_csv("demographics_only.csv")
synthetic = synth.generate(new_demographics)

Why microplex?

Use Cases

• Survey enhancement: Impute income variables from tax data onto census demographics
• Privacy-preserving synthesis: Generate synthetic data that preserves statistical properties without copying real records
• Data fusion: Combine variables from multiple surveys with different sample designs
• Missing data imputation: Fill in missing values conditioned on observed variables

Architecture

┌─────────────────────────────────────────────────────────┐
│                      Synthesizer                         │
├─────────────────────────────────────────────────────────┤
│                                                          │
│  Training:                                               │
│  ┌──────────┐    ┌──────────────┐    ┌──────────────┐  │
│  │ Training │───▶│ Transformer  │───▶│ Normalizing  │  │
│  │   Data   │    │ (log, std)   │    │    Flow      │  │
│  └──────────┘    └──────────────┘    └──────────────┘  │
│                                                          │
│  Generation:                                             │
│  ┌──────────┐    ┌──────────────┐    ┌──────────────┐  │
│  │ Context  │───▶│ Zero + Flow  │───▶│  Inverse     │  │
│  │  Vars    │    │   Sampling   │    │  Transform   │  │
│  └──────────┘    └──────────────┘    └──────────────┘  │
│                                                          │
└─────────────────────────────────────────────────────────┘

Documentation

Full documentation at cosilicoai.github.io/microplex

• Tutorial
• API Reference
• Benchmarks

Benchmarks

See benchmarks/ for comparisons against:

• CT-GAN: Conditional Tabular GAN (from SDV)
• TVAE: Tabular VAE (from SDV)
• Copulas: Gaussian copula synthesis (from SDV)
• synthpop: CART-based synthesis (R package, via rpy2)

Citation

@software{microplex2024,
  author = {Cosilico},
  title = {microplex: Microdata synthesis and reweighting using normalizing flows},
  year = {2024},
  url = {https://github.com/CosilicoAI/microplex}
}

License

MIT License - see LICENSE for details.