log_func :
A logarithmic function for an xreal-typed signal

The log_func primitive produces an xreal-typed output which is a logarithmic function of an xreal-typed input. That is,

    out = log(in).

The parameter base sets the base of the logarithmic function (default: M_E=2.718282). The parameter scale sets the additional scale factor applied to the output.

The primitive approximates the logarithmic function with a piecewise-linear (PWL) function and the parameters abstol sets the absolute tolerance of such PWL approximation. Specifically, the parameter abstol determines the number of PWL sections per decade.

NOTE: this primitive adds a unit timestep delay from its input to output for synchronization.

Input/Output Terminals

Name	I/O	Type	Description
out	output	xreal	output signal
in	input	xreal	input signal

Parameters

Name	Type	Default	Unit	Description
base	real	M_E	None	base of the log function
scale	real	1.0	None	scale factor
abstol	real	1e-3	None	absolute tolerance