# Solver Benchmark Correlation Thresholds

> Sub-skill of solver-benchmark: Correlation Thresholds (+1).

- Skill: `vamseeachanta/solver-benchmark-correlation-thresholds` (Agent Skill)
- Install (CLI): `npx skillmds@latest add vamseeachanta/solver-benchmark-correlation-thresholds`
- Raw SKILL.md: https://api.skillmd.com/api/skills/vamseeachanta/solver-benchmark-correlation-thresholds/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: vamseeachanta (https://skillmd.com/u/vamseeachanta)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/vamseeachanta/solver-benchmark-correlation-thresholds

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# Correlation Thresholds (+1)

## Correlation Thresholds


| Range | Interpretation | Action |
|-------|---------------|--------|
| > 0.99 | Excellent agreement | Solvers validated |
| 0.95 – 0.99 | Good agreement | Minor differences (phase convention, numerics) |
| 0.80 – 0.95 | Fair agreement | Investigate input differences |
| < 0.80 | Poor agreement | Likely input mismatch or unit error |
| Negative | Anti-correlated | Data extraction bug (wrong frequency order, wrong units) |

## Common Causes of Poor Correlation


1. **Negative correlations**: Frequency arrays in different order (ascending vs descending)
2. **Near-zero correlations**: Hz vs rad/s mismatch (factor of 2*pi offset)
3. **NaN correlations**: Zero standard deviation (all-zero DOF, e.g. yaw for head seas)
4. **Good amplitude, bad phase**: Different time convention (e^{+iwt} vs e^{-iwt})