Expression South Plugin¶
The fledge-south-expression plugin is a plugin that is used to generate synthetic data using a mathematical expression to generate data that changes over time. The user may configure the plugin with an expression of their choice and define a period in terms of samples put period of the output and the increment between each sample.
The parameters that can be configured are;
Asset Name: The name of the asset to be created inside Fledge.
Expression: The expression that should be evaluated to create the asset value, see below.
Minimum Value: The minimum value of x, where x is the value that sweeps over time.
Maximum Value: The maximum value of x, where x is the value that sweeps over time.
Step Value: The step in x for each call to the expression evaluation.
Expression Support¶
The fledge-south-expression plugin makes use of the ExprTk library to do run time expression evaluation. This library provides a rich mathematical operator set, the most useful of these in the context of this plugin are;
Mathematical operators (+, -, *, /, %, ^)
Functions (min, max, avg, sum, abs, ceil, floor, round, roundn, exp, log, log10, logn, pow, root, sqrt, clamp, inrange, swap)
Trigonometry (sin, cos, tan, acos, asin, atan, atan2, cosh, cot, csc, sec, sinh, tanh, d2r, r2d, d2g, g2d, hyp)
See Also¶
fledge-filter-expression - A Fledge processing filter plugin that applies a user define formula to the data as it passes through the filter
fledge-filter-fft - A Fledge processing filter plugin that calculates a Fast Fourier Transform across sensor data
fledge-filter-python35 - A Fledge processing filter that allows Python 3 code to be run on each sensor value.
fledge-filter-rms - A Fledge processing filter plugin that calculates RMS value for sensor data
fledge-filter-scale-set - A Fledge processing filter plugin that applies a set of sale factors to the data