alpha_lab/stock_1d/d033/alpha158_beta/BUG_ANALYSIS.md

# Data Pipeline Bug Analysis

## Summary

The generated embeddings do not match the database 0_7 embeddings due to multiple bugs in the data pipeline migration from qlib to standalone Polars implementation.

---

## Bugs Fixed

### 1. Market Classification (`FlagMarketInjector`) ✓ FIXED

**Original (incorrect):**
```python
market_0 = (instrument >= 600000)  # SH
market_1 = (instrument < 600000)   # SZ
```

**Fixed:**
```python
inst_str = str(instrument).zfill(6)
market_0 = inst_str.startswith('6')  # SH: 6xxxxx
market_1 = inst_str.startswith('0') | inst_str.startswith('3')  # SZ: 0xxx, 3xxx
market_2 = inst_str.startswith('4') | inst_str.startswith('8')  # NE: 4xxx, 8xxx
```

**Impact:** 167 instruments (4xxxxx, 8xxxxx - 新三板) were misclassified.

---

### 2. ColumnRemover Missing `IsN` ✓ FIXED

**Original (incorrect):**
```python
columns_to_remove = ['TotalValue_diff', 'IsZt', 'IsDt']
```

**Fixed:**
```python
columns_to_remove = ['TotalValue_diff', 'IsN', 'IsZt', 'IsDt']
```

**Impact:** Extra column caused feature dimension mismatch.

---

### 3. RobustZScoreNorm Applied to Wrong Columns ✓ FIXED

**Original (incorrect):**
Applied normalization to ALL 341 features including market flags and indus_idx.

**Fixed:**
Only normalize `alpha158 + alpha158_ntrl + market_ext + market_ext_ntrl` (330 features), excluding:
- Market flags (Limit, Stopping, IsTp, IsXD, IsXR, IsDR, market_0, market_1, market_2, IsST)
- indus_idx

---

## Critical Remaining Issue: Data Schema Mismatch

### `Limit` and `Stopping` Column Types Changed

**Original qlib pipeline expected:**
- `Limit`: **Boolean** flag (True = limit up)
- `Stopping`: **Boolean** flag (True = suspended trading)

**Current Parquet data has:**
- `Limit`: **Float64** price change percentage (0.0 to 1301.3)
- `Stopping`: **Float64** price change percentage

**Evidence:**
```
Limit values sample: [8.86, 9.36, 31.0, 7.32, 2.28, 6.39, 5.38, 4.03, 3.86, 9.89]
Limit == 0: only 2 rows
Limit > 0: 3738 rows
```

This is a **fundamental data schema change**. The current Parquet files contain different data than what the original VAE model was trained on.

**Possible fixes:**
1. Convert `Limit` and `Stopping` to boolean flags using a threshold
2. Find the original data source that had boolean flags
3. Re-train the VAE model with the new data schema

---

## Correlation Results

After fixing bugs 1-3, the embedding correlation with database 0_7:

| Metric | Value |
|--------|-------|
| Mean correlation (32 dims) | 0.0068 |
| Median correlation | 0.0094 |
| Overall correlation | 0.2330 |

**Conclusion:** Embeddings remain essentially uncorrelated (≈0).

---

## Root Cause

The **Limit/Stopping data schema change** is the most likely root cause. The VAE model learned to encode features that included binary limit/stopping flags, but the standalone pipeline feeds it continuous price change percentages instead.

---

## Next Steps

1. **Verify original data schema:**
   - Check if the original DolphinDB table had boolean `Limit` and `Stopping` columns
   - Compare with the current Parquet schema

2. **Fix the data loading:**
   - Either convert continuous values to binary flags
   - Or use the correct boolean columns (`IsZt`, `IsDt`) for limit flags

3. **Verify feature order:**
   - Ensure the qlib RobustZScoreNorm parameters are applied in the correct order
   - Check that `[alpha158, alpha158_ntrl, market_ext, market_ext_ntrl]` matches the 330-parameter shape

4. **Re-run comparison:**
   - Generate new embeddings with the corrected pipeline
   - Compare correlation with database