User-Defined Expression

Symbol

Description

This control block allows the user to write any mathematical expression that are evaluated at every time-step/iterations. Variables named "i1","i2"..."in" can be used to represent model inputs.

Example of supported expressions:

$sin(2*i1)$
$max(i1, i2)$
$sqrt(i1ˆ2 + i2ˆ2)$

This device should be used for "continuous" variables only. SIMBA will not consider discontinuities generated by user-defined expressions as such and therefore will not reduce the time steps. For example, it should not be used in place of a comparator controlling a switch.

The tables below present the list of functions and operators supported by this model.

Function name	Description	Example
abs	absolute value	abs(i1)
acos	arcus cosine	acos(i1)
acosh	hyperbolic arcus cosine	acosh(i1)
asin	arcus sine	asin(i1)
asinh	hyperbolic arcus sine	asinh(i1)
atan	arcus tangent	atan(i1)
atanh	hyperbolic arcus tangent	atanh(i1)
atan2	2-arguments arcus tangent	atan2(i1)
avg	average value	avg(i1,i2,...)
cos	cosine	cos(i1)
cosh	hyperbolic cosine	cosh(i1)
exp	exponential function	exp(i1)
ln	natural logarithm	ln(i1)
log	natural logarithm	log(i1)
log2	2-base logarithm	log2(i1)
log10	10-base logarithm	log10(i1)
max	maximal value	max(i1,i2,...)
min	minimal value	min(i1,i2,...)
rint	round to nearest interger	rint(i1)
sin	sine	sin(i1)
sinh	hyperbolic sine	sinh(i1)
sqrt	square root value	sqrt(i1)
sum	sum of all arguments	sum(i1,i2,...)
tan	tangent	tan(i1)
tanh	hyperbolic tangent	tanh(i1)

Operator	Description	Example
+	addition	i1+i2
-	subtraction	i1-i2
*	multiplication	i1*i2
/	division	i1/i2
^	raise to the power	i1^i2

Library

Control > Math

Pins

Name	Description
i1	Input 0
Out	Output

Parameters

Name	Description
NumberOfInputs	Number of Inputs
Expression	Mathematical expression
SamplingTime	-none or 0: No sampling. The system will be solved in the Newton loop (default). -auto: Inherit the sampling time of its source device. -Sampling Period: defined in seconds.