MapRange

The MapRange operation rescales a number from one range into another — the linear interpolation that turns a raw sensor reading into engineering units, a percentage into a PWM level, or a 0–1 fraction into any span you need.

Out Min equal to Out Max makes Out that one value whatever arrives, and the Editor marks both fields with an info mark.

Inputs

Port	Type	Required	Description
>	Any	No	Optional gate. When closed, the path stops and Out keeps its previous value.
In	Integer or Float	Yes	The value to rescale. A non-numeric or Nil value fails the Node; its On Error verb resolves the failure.

Outputs

Port	Type	Default	Description
Out	Float	Nil	The rescaled value. Always a Float.

Properties

Name	Type	Default	Description
In Min	Number	0	Value of In that maps to Out Min.
In Max	Number	1	Value of In that maps to Out Max.
Out Min	Number	0	Result at In Min.
Out Max	Number	1	Result at In Max.
Clamp to output range	Boolean	false	When true, the result is confined to the span between Out Min and Out Max. When false, an input outside the source range extrapolates past it.
On Error	Combo	Stop this branch	Per-op On Error verb (Stop this branch / Continue with the last value / Continue with the fallback). See the Error Handling guide.

State on Reload

Out is preserved across restarts.

The source range needs width

The Node refuses to compile while In Min equals In Max — “MapRange requires In Min != In Max” — because a source range of zero width has no slope to map along.

The output range has no such rule. Out Min greater than Out Max is a deliberate inversion: a rising input then produces a falling output.

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How It Works

1. Gate check — if the Gate is connected and closed, the path stops here.

2. Read the input — In must carry a number. Anything else fails the Node, and its On Error verb resolves the failure.

3. Rescale — Out = Out Min + (In − In Min) × (Out Max − Out Min) / (In Max − In Min).

4. Confine (optional) — with Clamp to output range on, the result is held between the smaller and the larger of Out Min and Out Max, whichever way round they were entered.

5. Emit — Out is written as a Float and the path continues.

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Examples

Fraction to percent

In Min: 0   In Max: 1   Out Min: 0   Out Max: 100

In: 0.42 → Out: 42.0

Raw ADC to volts

In Min: 0   In Max: 4095   Out Min: 0   Out Max: 3.3

In: 2048 → Out: 1.6506...

Inverted range

In Min: 0   In Max: 100   Out Min: 255   Out Max: 0

In: 25 → Out: 191.25  (a rising input drives a falling output)

Extrapolation vs clamping

In Min: 0   In Max: 1   Out Min: 0   Out Max: 100   In: 1.5

Clamp to output range off → Out: 150.0

Clamp to output range on → Out: 100.0

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Use Cases

• Engineering units — turn a raw analogue count into the pressure, temperature or voltage it represents.
• Driving an actuator — map a 0–100 percentage onto whatever span the device expects, inverting it where the hardware treats 0 as full scale.
• Normalising for comparison — bring two signals recorded on different scales onto a common 0–1 range before Comparing them.

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Error Handling

MapRange fails when In is unconnected, Nil, or not a number; the Node’s On Error verb resolves the failure.

Verb	What it does
Stop this branch (default)	This Node and its dependents stop; Out keeps its value and reads as a failed update.
Continue with the last value	Dependents run on the value Out already holds, not stamped as new; it reads as a failed update.
Continue with the fallback	Dependents run on Out’s per-output Fallback, stamped as this run’s value; it reads as a failed update. The Editor refuses a Task where the Fallback is unset.

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Limitations

• The four bounds are fixed at configuration time and cannot be driven from input ports.
• The mapping is linear. For a curve, chain a JavaScript node.
• Out is always a Float. Feed it through Convert when a downstream port requires an Integer.