Mirostat

Mirostat is an adaptive sampler that targets a specific output entropy (roughly perplexity) instead of relying on fixed temperature and nucleus filters. When enabled, it bypasses Temperature, TopP, TopK, and MinP.

Quick reference


Type	`int`
Default	`0` (disabled)
Range	`0` = disabled, `1` = Mirostat 1.0, `2` = Mirostat 2.0
Category	Adaptive sampler
Field on	`SamplerParameters.Mirostat`

What it does

Mirostat monitors the entropy of the output distribution and adjusts the sampling process to match a target entropy (MirostatTau). Higher measured entropy → Mirostat tightens. Lower → Mirostat relaxes.

Mirostat = 0 (default) — disabled. Standard Temperature + TopP + TopK + MinP pipeline is used.
Mirostat = 1 — Mirostat 1.0. Original algorithm from the paper.
Mirostat = 2 — Mirostat 2.0. Simplified and usually preferred; faster convergence.

When Mirostat is enabled, the standard filters (TopP, TopK, MinP, TypicalP, TopNSigma) are effectively bypassed. Temperature tuning is ignored — Mirostat manages its own temperature-like adjustments internally.

When to change it

Scenario	Value
Default — use standard filters	`0`
Adaptive perplexity-targeting (preferred)	`2`
Older Mirostat 1.0 (rarely preferred)	`1`

Consider Mirostat when:

You want consistent perplexity across very long outputs.
Fixed temperature produces output that is either too tight or too loose in different parts of the same generation.
Research / experimentation with entropy-aware sampling.

Example

var preset = new Qwen25Preset();
preset.SamplerParameters.Mirostat = 2;           // Mirostat 2.0
preset.SamplerParameters.MirostatTau = 5.0f;     // target entropy
preset.SamplerParameters.MirostatEta = 0.1f;     // learning rate

using var api = AsposeLLMApi.Create(preset);

Interactions

MirostatTau — target entropy.
MirostatEta — learning rate.
Temperature, TopP, TopK, MinP, TypicalP, TopNSigma — all bypassed when Mirostat is active.
DynatempRange — alternative entropy-aware sampler; do not combine.
Seed — still affects the RNG; reproducibility works with Mirostat.

What’s next

MirostatTau — entropy target.
MirostatEta — learning rate.
DynatempRange — alternative adaptive approach.

DrySequenceBreakers MirostatTau