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Aux Math

Aux Math lets you create custom derived channels using mathematical expressions. This is useful for computing values that iRacing doesn't provide directly.

Expression Syntax

Expressions use backtick-quoted channel names and standard math operators:

@TBdiff = `Throttle` - `Brake`

This creates a new channel called TBdiff with the difference between throttle and brake at every sample.

Examples

Expression Description
@TBdiff = `Throttle` - `Brake` Throttle minus brake overlap
@SpeedKmh = `Speed` * 3.6 Convert m/s to km/h
@SlipAngle = atan2(`VelocityY`, `VelocityX`) Calculate slip angle
@LateralG = `LatAccel` / 9.81 Convert acceleration to G-force
@BrakePct = `Brake` * 100 Brake as percentage

Supported Operations

  • Arithmetic+, -, *, /, ** (power)
  • Functionsabs, sqrt, sin, cos, tan, atan2, log, exp, min, max
  • Constants — standard numeric values

Configuration

In the workflow panel:

  1. Select Branch — which data branches to apply the expression to (All, or specific)
  2. Select Channel In — which input channel type (Raw, Pred, Val)
  3. Write your expression in the text field

Tips

  • Derived channels appear in plots with an @ prefix
  • You can chain multiple Aux Math nodes for complex calculations
  • Expressions are applied element-wise across all samples