Math Function

Use this node to compute a mathematical result from message data, metadata, or entity attributes and save it back to the message or directly to the database — for example, converting raw ADC readings to engineering units, accumulating a running total in a server attribute, or computing a heat index from temperature and humidity without writing a script node.

Select one of the built-in operations or CUSTOM for arbitrary expressions:

Write any mathematical expression using the predefined argument variable names shown in the configuration form. Available built-in constants: pi/π (3.14159…), e (2.71828…), φ (1.61803…). Available functions: all standard trig/log/sqrt/abs functions plus ln(x), lg(x) (log₁₀), logab(a, b) (logₐ b).

Expression examples:

Each argument specifies where to read its value from:

Argument keys support templatization — use ${metadataKey} and $[dataKey] to build key names dynamically.

Each argument can have a default value used when the source is missing or invalid.

The computation result can be written to one or more destinations:

For ATTRIBUTE and TIME_SERIES destinations, you can optionally also write the result to the message body and/or metadata for downstream nodes.

Set Result value precision to the number of decimal places (half-up rounding). 0 gives an integer.

1. For each argument, retrieve the value from its configured source. If a value is missing and no default is set, route via Failure.
2. Convert all values to double. If conversion fails, route via Failure.
3. Perform the mathematical calculation.
4. Round the result to the configured precision.
5. Write the result to all configured destinations.
6. Route the message via Success.

State: originator has server attribute totalConsumption = 12543.8. Data: { "deltaConsumption": 15.7 }.

{
  "operation": "ADD",
  "arguments": [
    { "name": "x", "type": "ATTRIBUTE", "key": "totalConsumption", "attributeScope": "SERVER_SCOPE", "defaultValue": 0 },
    { "name": "y", "type": "MESSAGE_BODY", "key": "deltaConsumption" }
  ],
  "result": {
    "type": "ATTRIBUTE",
    "key": "totalConsumption",
    "attributeScope": "SERVER_SCOPE",
    "resultValuePrecision": 2,
    "addToBody": true,
    "addToMetadata": false
  }
}

Outgoing data: { "deltaConsumption": 15.7, "totalConsumption": 12559.5 }. Attribute updated to 12559.5. Routes via Success.

Data: { "distance": 250, "frequency": 2400, "signalStrength": -45 }.

{
  "operation": "CUSTOM",
  "customFunction": "100 * e^(-x / 1000) * (1 + 0.5 * sin(2 * pi * y / 1000)) * sqrt(abs(z))",
  "arguments": [
    { "name": "x", "type": "MESSAGE_BODY", "key": "distance" },
    { "name": "y", "type": "MESSAGE_BODY", "key": "frequency" },
    { "name": "z", "type": "MESSAGE_BODY", "key": "signalStrength" }
  ],
  "result": {
    "type": "MESSAGE_BODY",
    "key": "signalQuality",
    "resultValuePrecision": 2,
    "addToBody": true,
    "addToMetadata": false
  }
}

Outgoing data includes: "signalQuality": 675.98. Routes via Success.

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "TbMathNodeConfiguration",
  "type": "object",
  "required": ["operation", "arguments", "result"],
  "additionalProperties": false,
  "properties": {
    "operation": { "type": "string" },
    "customFunction": { "type": "string" },
    "arguments": {
      "type": "array",
      "items": {
        "type": "object",
        "required": ["name", "type", "key"],
        "properties": {
          "name": { "type": "string" },
          "type": { "type": "string", "enum": ["CONSTANT","MESSAGE_BODY","MESSAGE_METADATA","ATTRIBUTE","TIME_SERIES"] },
          "key": { "type": "string" },
          "attributeScope": { "type": "string" },
          "defaultValue": { "type": "number" }
        }
      }
    },
    "result": {
      "type": "object",
      "required": ["type", "key"],
      "properties": {
        "type": { "type": "string", "enum": ["MESSAGE_BODY","MESSAGE_METADATA","ATTRIBUTE","TIME_SERIES"] },
        "key": { "type": "string" },
        "attributeScope": { "type": "string" },
        "resultValuePrecision": { "type": "integer" },
        "addToBody": { "type": "boolean" },
        "addToMetadata": { "type": "boolean" }
      }
    }
  }
}