eldo_user

Optimization
Types of Design Objective
The ratio μ m
(i)
/ μ m
(j)
can be interpreted as the relative weight of the ith objective compared with
the jth objective. This is useful when you want to alter weights to get lower values of a chosen
objective, for example the kth. To find an optimal point which trades off the kth objective,
increase the weight on the kth objective.
Related Topics
Specifying Design Objectives Using .EXTRACT
Specifying Design Objectives Using .OBJECTIVE
Design Objectives for Multi-Point Simulation
Scaling Design Objectives
Goal Values Objectives
This topic explains how to specify design objectives that define goal values on extracted
measures. With this type of design objective the extracted measure aims to get as close as
possible to a goal value r.
Objectives that define goals values on measures are specified using the .OBJECTIVE command
as follows:
* Goal values on measures
.OBJECTIVE EXTRACT_INFO LABEL=F_R
+ {$MACRO|FUNCTION}
+ GOAL=R
+ [WEIGHT=MU_R]
The optional weight μ r is a positive number, defaulting to one.
Multiple Specifications
If multiple objectives are qualified as GOAL=R, a weighted objective function is built using the
non-linear least squares approach, that is by minimizing the squared difference between the
actual value of the measure f r and the goal value r:
μ r (f r − r) 2
Consider the following example:
* Aggregation of two Minimize statements
.OBJECTIVE EXTRACT_INFO_1 LABEL=F_R_1
+ {$MACRO|FUNCTION}
+ GOAL=R_1 WEIGHT=MU_R_1
.OBJECTIVE EXTRACT_INFO_2 LABEL=F_R_2
+ {$MACRO|FUNCTION}
+ GOAL=R_2 WEIGHT=MU_R_2
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Eldo® User's Manual, 15.3