@lal12/node-red-curve

node-red-curve

A fork (with bugfixes and improvements) of https://github.com/sbarwe/node-red-contrib-curve.

A function node for a mathematical expression f(x) for creating simulation data, characteristics, calibration data and other numerical output based on a numeric input.

• easy expression formula like x^2, sqrt(x), nthRoot(x), exp(x), sin(x), cos(x) etc. (see function-plot)

• define which property from msg to use for x value input

• use Mustache-Syntax to include variables from msg or context

• Use the modulo-operator (%) to create infinite ranged functions like easings.

Examples:

easeOutElastic

-0.5*exp(-6x)*(-2*exp(6x) + sin(12x) + 2cos(12x))

easeOutQuad

-{{change}}*(x/{{duration}})*(x-2)+{{start}}

easeInOutQuad

((2*x/{{duration}}) <1)*({{change}}*0.5*x*x) + (2*x/{{duration}}>=1)*-0.5*{{change}}*((x-1)*(x-3)-1) + {{start}}

Node Settings

Value x

The property from msg to use for the value x for the function input

Function

A function f(x) defined according to built-in-math-eval as a function expression. You can use Mustache-Syntax to include values from the flow or global context or msg. The function would then be reevaluated on each input.

The function can be overriden by a provided msg.function as input.

Performance

The node is most performant when not using Mustache-Syntax or redefine function expression via msg.function as this leads to an recompilation of the function expression with each incoming msg. There is currently no function expression cache. This node will reuse the incoming msg for its output.

Note: to gain more performance use a function-node for calculation. This is more a convenient node for easier setup of curves.

Details

When using Mustache-Syntax these values will be replaces bei "0" for the preview window, so function may not get plotted correctly. You can use the node-red-contrib-counter node to create a continous input stream of (0,1,2,4,5,6...).

This node uses the work of Mauricio Poppe for visualization and function expression parsing. This node-red node is just a wrapper around this library.

Changes

See Change Log for details

Discussions and suggestions

Use the GitHub issues log for raising issues or contributing suggestions and enhancements.

Contributing

If you would like to contribute to this node, you can contact the autor via GitHub or raise a request in the GitHub issues log.

Developers/Contributors

• newest version lal12
• Based on function-plot work of Mauricio Poppe
• original Node-RED node wrapper Sebastian Barwe
• Node template from Julian Knight