# Parameter Lists I – Basic Use

Elham Esfehani

It is recommended that you work through the section Connection techniques I – naming policy ‘integrate’ before you start here. In MOSAICmodeling the use of the variables of an equation system is generally left unspecified until the evaluation step where the problem description is added. In many cases it is useful, however, to classify some variables of an equation or function as a parameter right from the beginning. The basic handling of this feature is described in this tutorial.

Rules

• Parameters are classified into a separate group.
• Within the same namespace parameters of the same name are assumed to be the same parameter.

Example problem

Equation System One

$latex x_{i=1}+b \cdot x_{i=2} = C+A$
$latex C \cdot (x_{i=2})^{2} = -a+x_{i=1}+0.5 \cdot A$

Notation x

Base Names:

[table sort=”desc,asc”]
Name, Description
$latex x$,value x
$latex a$,parameter a
$latex b$,parameter b
$latex c$,parameter c
$latex d$,parameter d
[/table]

Indices:

[table sort=”desc,asc”]
Name, Description
$latex i$,value index
[/table]

Parameter List One

$latex A$

Problem description
Design variables and their corresponding values:

$latex a = 1$

$latex b = 1.5$

$latex C=-1$

Parameter and the corresponding value:

$latex A=-2.5$

Iteration variables and their corresponding guess values:
$latex x_{i=1} = 0$
$latex x_{i=2} = 0$

Expected solution:

$latex x_{i=1} = -0.8563$
$latex x_{i=2} = -1.7625$

Creating the necessary notations

• Create ‘Notation x’ and ‘Notation z’ as specified above or in section of previous examples. If you already created these notations in previous tutorials, you may use them here.

Creating the parameter list

• Select the Param List Editor in the Editor Bar at the left hand side.
• Press [Select] in the notation file field and load ‘Notation z’.
• Press [Add], which opens the Create Variable Naming dialog.
• Write A into the field Tex Expression, press [Render] and press [OK].
• Save the parameter list.

Creating the equations using the parameter list

• Select the Equation Editor in the Editor Bar at the left hand side.
• Load ‘Notation x’ as a notation for the equation system.
• Below the notation file panel there is a similar file panel for Parameters.
• Use this file panel to load the parameter list created before.
• Enter a description for the equation.
• Enter a latex expression for the first equation of section [equation system one] into the MosaicLatex section.
• As usual press [Render].
• Save the equation.
• Repeat the above steps for the second equation of section [equation system one].

Creating the equation system

• Create a new equation system using ‘Notation x’ and connecting the two equations in the section [equation system one], under the naming policy ‘integrate’ without any connector.

Evaluating the equation system

• Select the Evaluation Editor in the Editor Bar at the left hand side.
• Load and instantiate the equation system as usual.
• Activate the tab Parameter Specification.
• You should find parameter A in this list with its standard value of 0.
• Change this value according to the problem description above.
• You may save the parameter list, which now constitutes of only one parameter, in a separate file.
• Enter the missing information according to the above problem description and solve the problem.