obikmer/UserDocMD/usage/estimate.md

# estimate

Estimate approximate-index parameters (z, evidence bits, false-positive rate) before building an index with `--approx`, without touching any files.

```bash
obikmer estimate [OPTIONS]
```

## Options

| Option | Default | Description |
|---|---|---|
| `-k, --kmer-size` | `31` | Kmer size used at query time (matches `index`'s `--kmer-size`) |
| `-z, --findere-z` | none | Findere z parameter |
| `--evidence-bits` | none | Fingerprint bits per slot (b) |
| `--fp` | none | Target false-positive rate per z-window |

Any two of `-z`, `--evidence-bits`, `--fp` may be given; the third is derived using the same model as `index --approx` and `convert --approx-evidence` ($FP = 1 / 2^{b \cdot z}$). The report printed to stdout includes: query $k$, effective indexed $k$ ($k-z+1$), $z$, evidence bits, per-kmer false-positive rate, and per-z-window false-positive rate.