Algebraic Expression Model

Class Name

• RAlgebraicExpressionModel

Location in Objects Pane

• Models > Model > Generic > Algebraic Expression

Model Description

Model Form

• This model evaluates a mathematical expression.

DDM Sensitivities

• No

Properties

Object Name

• Name of the object in Rt
• Allowable characters are upper-case and lower-case letters, numbers, and underscore (“_”).
• The name is unique and case-sensitive.

Display Output

• Determines whether the model is allowed to print messages in the Output Pane.

Expression

• The mathematical expression to be evaluated, for example:

1.0 - x2/(1000.0*x3) - (x1/(200.0*x3))^2

• The following functions can be used in the expression of the function:

Name	No. of Arguments	Explanation
sin	1	sine function
cos	1	cosine function
tan	1	tangent function
asin	1	arcus sine function
acos	1	arcus cosine function
atan	1	arcus tangent function
sinh	1	hyperbolic sine function
cosh	1	hyperbolic cosine
tanh	1	hyperbolic tangent function
asinh	1	hyperbolic arcus sine function
acosh	1	hyperbolic arcus cosine function
atanh	1	hyperbolic arcus tangent function
log2	1	logarithm to the base 2
log10	1	logarithm to the base 10
log	1	logarithm to the base 10
ln	1	logarithm to base e (2.71828...)
exp	1	e raised to the power of x
sqrt	1	square root of a value
sign	1	sign function -1 if x<0; 1 if x>0
rint	1	round to nearest integer
abs	1	absolute value
if	3	if ... then ... else ...
min	var.	min of all arguments
max	var.	max of all arguments
sum	var.	sum of all arguments
avg	var.	mean value of all arguments

• The following operators can be used in the expression of the function:

Operator	Meaning	Priority
=	assignment	-1
and	logical and	1
or	logical or	1
xor	logical xor	1
<=	less or equal	2
>=	greater or equal	2
!=	not equal	2
==	equal	2
>	greater than	2
<	less than	2
+	addition	3
-	subtraction	3
*	multiplication	4
/	division	4
^	raise x to the power of y	5

Output

• The calculated value of mathematical expression
• The output is an automatically generated generic response object, which takes the object name of the model plus “Response”.

Right-click Menu

Remove

• Removes the object.