STFunc-expression

expression (STFunc)

Works with all licenses.

Function that can be defined by an arbitrary mathematical expression.

expression Parameters

expression (string)

Expression to be evaluated, involving the arithmetic operators + (addition), - (subtraction), * (multiplication), / (division), and ** (exponentiation), and the below functions of position and/or time:

Function	Mathematical Description	General Description
pow(x,y)	\(x^y\)	exponential, arbitrary base
exp(x)	\(e^x\)	exponential, base \(e\)
sin(x)	\(\sin\left(x\right)\)	sine
cos(x)	\(\cos\left(x\right)\)	cosine
tan(x)	\(\tan\left(x\right)\)	tangent
asin(x)	\(\arcsin\left(x\right)\), \(x \in \left[-1,1\right]\)	inverse sine
acos(x)	\(\arccos\left(x\right)\), \(x \in \left[-1,1\right]\)	inverse cosine
atan(x)	\(\arctan\left(x\right)\), \(x \in \left[-\pi/2,\pi/2\right]\)	inverse tangent
atan2(y,x)	\(\arctan\left(y/x\right)\); \(x\) and \(y\) not both 0,	inverse tangent, returns angles in correct quadrant
	\(x=0\) returns \(\pm \pi/2\)
sinh(x)	\(\sinh\left(x\right)\)	hyperbolic sine
cosh(x)	\(\cosh\left(x\right)\)	hyperbolic cosine
tanh(x)	\(\tanh\left(x\right)\)	hyperbolic tangent
ln(x)	\(\log_e\left(x\right)\)	logarithm, base \(e\)
log(x)	\(\log_e\left(x\right)\)	logarithm, base \(e\)
log10(x)	\(\log_{10}\left(x\right)\)	logarithm, base \(10\)
mod(x,y)	\(x - \lfloor x/y \rfloor y\)	floating point remainder
inv(x)	\(-x\)	additive inverse
H(x)	\(H\left(x\right)=\left\{\begin{array}{lr}0 & , x<0\\0.5 & , x=0\\1 & , x>0\end{array}\right.\)	Heaviside step function
J0(x)	\(J_0\left(x\right)\)	Bessel function of the first kind, order 0
J1(x)	\(J_1\left(x\right)\)	Bessel function of the first kind, order 1
J2(x)	\(J_2\left(x\right)\)	Bessel function of the first kind, order 2
J3(x)	\(J_3\left(x\right)\)	Bessel function of the first kind, order 3
abs(x)	\(\left|x\right|\)	absolute value
sqrt(x)	\(\sqrt{x}\)	square root
rand(x)		uniform random number in \(\left[0, 1\right)\), independent of \(x\)
gauss(x,y)		Gaussian random number with standard deviation \(x\) and mean \(y\)
ceil(x)	\(\lceil x \rceil\)	smallest integer not less than x
floor(x)	\(\lfloor x \rfloor\)	largest integer not greater than x
min(x,y)	\(x\) if \(x \le y\), else \(y\)	minimum
max(x,y)	\(x\) if \(x \ge y\), else \(y\)	maximum

Example expression Block

<STFunc component0>
  kind = expression
  expression = 100.*sin(2.0e9*t)
</STFunc>