Registry / data / node-red-contrib-calc

node-red-contrib-calc

library1.0.6jsnpmunverified

node-red-contrib-calc is a Node-RED node designed to perform a range of basic mathematical operations directly within Node-RED flows. Currently at version 1.0.6, it primarily receives maintenance updates, with recent releases focusing on expanding available operations like `truncate` and enhancing result formatting. Unlike traditional JavaScript libraries, this package integrates as a graphical node in the Node-RED editor. Its core differentiator lies in providing a simplified, visual interface for common arithmetic, aggregation (min, max, average), and rounding tasks, allowing users to easily inject, process, and output numerical data within their IoT and automation workflows without writing custom functions. It is positioned as a simpler alternative to more advanced statistical packages like `node-red-contrib-statistics`.

data

npm install node-red-contrib-calc

github ↗package ↗

INSTALL

IMPORT

SIG · NODE-RED-CONTRIB-C

node-red-contrib-calc

datajavascriptv1.0.6

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

This example Node-RED flow demonstrates how to configure the `calc` node to find the maximum value from an array of numbers injected into the flow, and then display the result in the Node-RED debug sidebar.

[ { "id": "b6bc5399.8385e", "type": "calculator", "z": "4142483e.06fca8", "name": "", "inputMsgField": "payload", "outputMsgField": "payload", "operation": "max", "constant": "", "round": false, "decimals": 0, "x": 640, "y": 3060, "wires": [ ["4c297cba.7585a4"] ] }, { "id": "e5a3b930.003428", "type": "inject", "z": "4142483e.06fca8", "name": "", "topic": "", "payload": "[321,123,333,222,111]", "payloadType": "json", "repeat": "", "crontab": "", "once": false, "onceDelay": 0.1, "showConfirmation": false, "confirmationLabel": "", "x": 420, "y": 3060, "wires": [ ["b6bc5399.8385e"] ] }, { "id": "4c297cba.7585a4", "type": "debug", "z": "4142483e.06fca8", "name": "", "active": true, "tosidebar": true, "console": false, "tostatus": false, "complete": "false", "x": 830, "y": 3060, "wires": [] } ]

Debug

Known issues

gotchaThe input data structure (single number, array of numbers, or fixed-length array) required by the node depends on the specific mathematical operation selected. Supplying incorrect data types or structures can lead to errors.

fix

Consult the node's configuration sidebar or documentation to understand the exact input requirements for the chosen operation. Use debug nodes upstream to verify input message content and type.

affects: >=1.0.0

gotchaThis node is designed for basic mathematical calculations and aggregations. For advanced statistical analysis, complex data transformations, or machine learning capabilities, it is generally insufficient.

fix

For advanced statistical analysis or more complex mathematical transformations, consider using `node-red-contrib-statistics` or implementing custom JavaScript functions within a Node-RED `function` node.

affects: >=1.0.0

gotchaThe `round` and `truncate` options for decimal places behave differently. `Round` performs standard mathematical rounding (e.g., 2.5 rounds to 3), while `truncate` simply cuts off decimal places (e.g., 2.9 truncates to 2) without rounding up.

fix

Carefully select between `round` and `truncate` based on the desired numerical precision behavior. Test with edge cases to ensure the output matches expectations.

affects: >=1.0.6

Errors

Common errors & fixes

Error: Input for operation 'Multiply' must be an array of at least 2 numbers.

An operation requiring an array of multiple numbers (e.g., 'Multiply', 'Average') received a single number or an array with too few elements.

fix

Ensure the input message field (e.g., `msg.payload`) contains an array with the minimum required number of elements for the selected operation, for example, `[2, 3]` for multiplication.

TypeError: Cannot read properties of undefined (reading 'length')

The configured input message field (e.g., `msg.payload`) is either undefined, null, or does not contain a valid number or an array of numbers, preventing the node from processing.

fix

Verify that the input message field, as configured in the node's properties, correctly points to a numeric value or an array of numbers. Use an upstream debug node to inspect `msg` content.

Output displays 'NaN' (Not a Number) in debug sidebar.

An operation was performed on non-numeric input data, or a mathematical operation resulted in an undefined outcome (e.g., division by zero, or an operation on `Infinity`).

fix

Check upstream nodes to ensure only valid numeric inputs are being sent to the `calc` node. Use debug nodes to inspect the input `msg.payload` or the chosen input field before it reaches the calculator node.

Upgrade

Version history

1.0.6latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/bartbutenaers/node-red-contrib-calc ↗

packagehttps://www.npmjs.com/package/node-red-contrib-calc ↗