MinP

MinP defines a minimum probability threshold relative to the top token. Any candidate whose probability is below MinP × p(top) is discarded.

Quick reference
Type float
Default 0.05
Range 0.0 – 1.0
Category Core sampling
Field on SamplerParameters.MinP

What it does

After the other filters run, compute the top candidate’s probability p_max. For every remaining token, check if its probability is at least MinP × p_max. If not, discard.

  • MinP = 0.0 — filter disabled.
  • MinP = 0.05 (default) — keep tokens at 5 % of the top token’s probability or higher.
  • MinP = 0.1 — keep tokens at 10 % or higher (stricter).

Unlike TopP (which is cumulative-mass aware) and TopK (which is count aware), MinP is relative-to-top aware. It adapts to distribution shape differently: on a peaked distribution it keeps fewer tokens; on a flat distribution it keeps more.

When to change it

Scenario Value
Disabled 0.0
Loose tail retention 0.02
Default balance 0.05
Conservative, drops more tail 0.1 – 0.15

Some users recommend MinP as a replacement for TopP — simpler to reason about, less sensitive to vocabulary size. The default 0.05 is a conservative, broadly safe value.

Example

var preset = new Qwen25Preset();
preset.SamplerParameters.MinP = 0.1f; // stricter tail cutoff

using var api = AsposeLLMApi.Create(preset);
string reply = await api.SendMessageAsync("Describe today's weather in three words.");
Console.WriteLine(reply);

Creative writing with wider tail:

preset.SamplerParameters.MinP = 0.02f;
preset.SamplerParameters.Temperature = 0.9f;
// More diverse sampling, still filtered against very-low-probability tokens.

Interactions

  • Temperature — applied before MinP.
  • TopP — can coexist; final candidate set respects both.
  • TopK — count-based cap; stacks with MinP.
  • MinKeep — floor; MinP never cuts below MinKeep.
  • Mirostat — bypasses MinP when active.

What’s next

TopK Seed