RopeFreqScale

RopeFreqScale is a multiplicative scaling factor applied to RoPE frequencies. It implements simple linear scaling of positions — equivalent to Linear RopeScalingType at the value set here.

Quick reference


Type	`float?`
Default	`null` (use model default)
Range	`0` – `1.0`; `< 1.0` stretches the context window
Category	Position encoding
Field on	`ContextParameters.RopeFreqScale`

What it does

RoPE frequencies are scaled by RopeFreqScale. A scale of 1.0 is no scaling. Smaller values stretch the effective context:

RopeFreqScale = 1.0 — no scaling.
RopeFreqScale = 0.5 — effective context doubled (2× training window). Moderate quality loss.
RopeFreqScale = 0.25 — 4× training window. More quality loss.

This is the simplest context-extension approach. More sophisticated algorithms (Yarn, LongRope) produce better quality at the same effective extension.

When to change it

Scenario	Value
Default (use model metadata)	`null`
Simple 2× extension	`0.5` with `RopeScalingType = Linear`
Prefer better algorithms	Use `RopeScalingType = Yarn` instead

Modern built-in presets target models that already ship with proper scaling metadata. Override only when adapting a model without adequate metadata.

Example

using Aspose.LLM.Abstractions.Models;

var preset = new Qwen25Preset();
preset.ContextParameters.RopeScalingType = RopeScalingType.Linear;
preset.ContextParameters.RopeFreqScale = 0.5f;  // 2x linear extension

Interactions

RopeScalingType — Linear uses this scale; Yarn/LongRope have their own knobs.
RopeFreqBase — base frequency.
ContextSize — the target extended context size.

What’s next

RopeScalingType — algorithm selector.
YarnOrigCtx — better long-context extension via YaRN.
Long context tuning — practical recipes.

RopeFreqBase YarnExtFactor