Math Functions

Settings

Evaluation

• Continuous - the expressions are evaluated constantly at 100Hz
• On Event - the expressions are evaluated only when the assigned event occurs

Variable Name

This is the variable name that will become available for use in the expression.

Derivative

When checked, an additional variable will become available containing the derivative of the input channel. The derivative variable uses the standard variable name with a d prefix.

e.g. If the channel variable is EngineSpeed, then the derivative variable will be dEngineSpeed.

Expression Syntax

Expressions are written using the Expr language.

Numeric Literals

Arithmetic Operators

Comparison Operators

Returns 1 (true) or 0 (false).

Logical Operators

Conditional (Ternary) Operator

condition ? valueIfTrue : valueIfFalse

Example: rpm > 3000 ? 1 : 0

Local Variables

Use let to declare intermediate values within an expression. Separate statements with ;.

let x = rpm / 60;
let y = x * 2;
y + offset

Special Variables:

• timeDelta Time since last evaluation in seconds.
• previousResult Previous result of the expression.

Math Utilities:

All trig functions are in radians.

• math.Sin(x) Returns the sine of x.
• math.Cos(x) Returns the cosine of x.
• math.Tan(x) Returns the tanginent of x.
• math.Asin(x) Returns the arcsine of x.
• math.Acos(x) Returns the arccosine of x.
• math.Atan(x) Returns the arctangent of x.
• math.Hypot(p, q) Returns the hypotenuse of p and q.
• math.Exp(x) Returns the base e exponential of x.
• math.Abs(x) Returns the absolute of x.
• math.Log(x) Returns the natural log of x.
• math.Log10(x) Returns the decimal log of x.
• math.Sqrt(x) Square root.
• math.Min(x, y) Mimimum.
• math.Max(x, y) Maximum.
• math.Clamp(x, min, max) Clamps x between min and max.
• math.Pow(x, y) Returns x to the power of y.
• math.Pow10(n) Returns 10 to the power of n.
• math.Round(x) Rounds to the nearest ingteger.
• math.Deg2Rad(x) Converts degrees to radians.
• math.Rad2Deg(x) Converts radians to degrees.
• math.Blend(ratio, x, y) Blends x and y together depending on the ratio. A ratio of 0 uses all of x, 0.5 half of each and 1 uses all of y.

Filter Utilities:

Only one of each type of filter function can be used per expession.

• filter.MovingAverage(input, n) Returns the moving average based on n samples. The value of n must be constant.
• filter.Exponential(input, smoothing) Returns the exponential filtered value based on smoothing factor. Smoothing factor ranges from 0 to 1, with 0 being the most filtering. The smoothing factor can be changed dynamically.
• filter.Schmitt(input, lowValue, highValue) Schmitt trigger. Turns the input into 1 once the value has gone above highValue, then to 0 once the value has gone below lowValue.
• filter.DelayedSchmitt(input, lowValue, highValue, offTimeS, onTimeS) Schmitt trigger. Turns the input into 1 once the value has gone above highValue for onTimeS, then to 0 once the value has gone below lowValue for offTimeS.
• filter.RateOfChange(input, maxPositiveRatePerSecond, maxNegativeRatePerSecond) Limits the rate of change of the input. The rate of change is limited to the maxPositiveRatePerSecond and maxNegativeRatePerSecond. Both rates limits are positive numbers.
• filter.Median(input, n) Returns the median of the last n samples. The value of n must be constant and should be an odd number.
• filter2.MovingAverage(input, n) Same as filter.MovingAverage.
• filter2.Exponential(input, smoothing) Same as filter.Exponential.
• filter3.... Same as filter…

Calculus Utilities:

• calc.Integrate(input, deltaTime, initial, enable) Returns the integral of the input. The initial value is the starting value of the integral. If the enable flag is false, the integral is reset to the initial value..
• calc.IntegrateClamped(input, deltaTime, initial, min, max, enable) Same as calc.Integrate, but clamps the output between min and max.