# Dependencies

## Core Library Wiring

### Database Layer
```
ibis → DuckDB → MotionDatabase singleton (database.py)
         ↑
    sqlglot (ibis dependency)
```

### Data Processing
```
pandas → (used throughout for DataFrame operations)
numpy → (used by sklearn, scipy, umap)
scipy → spatial.procrustes for window alignment
```

### ML Pipeline
```
sklearn.cluster → KMeans, Procrustes
sklearn.preprocessing → StandardScaler
umap → UMAP (optional, graceful fallback)
```

### Visualization
```
plotly → explorer_helpers.py chart builders
st.plotly_chart → explorer.py rendering
```

### Streamlit
```
streamlit → all pages, @st.cache_data decorators
```

## Optional Dependencies
| Package | Required | Fallback |
|---------|----------|----------|
| `umap` | No | Use raw SVD vectors (first 2 dims) |
| `plotly` | Yes | Raises ImportError |
| `duckdb` | Yes | — |
| `ibis` | Yes | — |
| `sklearn` | Yes | — |

## Singleton Instances
| Module | Instance | Type |
|--------|----------|------|
| `database.py` | `db` | `MotionDatabase` |
| `config.py` | `config` | `Config` (dataclass) |
| `config.py` | `PARTY_COLOURS` | `dict[str, str]` |

## Key Imports by File
```
explorer.py:
  - import streamlit as st
  - from database import db
  - from explorer_helpers import *

explorer_helpers.py:
  - import pandas as pd
  - import plotly.graph_objects as go
  - from database import db (optional, for type hints)

database.py:
  - import ibis
  - import duckdb
  - from config import config, PARTY_COLOURS

config.py:
  - from dataclasses import dataclass, field
  - import streamlit as st (optional, for warnings)
```

## Environment
- Python ≥3.13
- Environment variables via `.env` (DB path, API keys)
- No `.env` values in constraint files (security)