RandomStartPointSet

Random start points

Description

A RandomStartPointSet object describes how to generate a set of pseudorandom points for use with MultiStart. A RandomStartPointSet object does not contain points. It contains parameters for generating the points when MultiStart runs or when you use the list function.

Creation

Syntax

rs = RandomStartPointSet

rs = RandomStartPointSet(PropertyName=Value)

rs = RandomStartPointSet(oldrs,PropertyName=Value)

Description

rs = RandomStartPointSet creates a default RandomStartPointSet object.

rs = RandomStartPointSet(PropertyName=Value) sets properties for the RandomStartPointSet object. PropertyName is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as PropertyName1=Value1, ..., PropertyNameN=ValueN. Properties that you do not specify retain their default values.

For example, rs = RandomStartPointSet(NumStartPoints=50) creates an object that uses 50 start points instead of the default 10.

rs = RandomStartPointSet(oldrs,PropertyName=Value) creates a copy of the oldrs RandomStartPointSet object and sets properties of rs.

Input Arguments

oldrs — Start points description to update

RandomStartPointSet object

Start points description to update, specified as an existing RandomStartPointSet object.

Output Arguments

rs — Random start points description

RandomStartPointSet object

Random start points description, returned as a RandomStartPointSet object. The description rs enables MultiStart and list to create start points.

Properties

ArtificialBound — Absolute value of default bounds for unbounded components

1000 (default) | positive scalar

Absolute value of the default bounds for unbounded components, specified as a positive scalar.

Example: 1e2

Data Types: double

NumStartPoints — Number of start points

10 (default) | positive integer

Number of start points, specified as a positive integer.

Example: 40

Data Types: double

Object Functions

list	List start points

Examples

Create Default RandomStartPointSet

Create a default RandomStartPointSet object.

rs = RandomStartPointSet

rs = 
  RandomStartPointSet with properties:

     NumStartPoints: 10
    ArtificialBound: 1000

Create RandomStartPointSet

Create a RandomStartPointSet object for 40 points.

rs = RandomStartPointSet(NumStartPoints=40);

Create a problem with 3-D variables, lower bounds of 0, and upper bounds of [10,20,30].

problem = createOptimProblem("fmincon",x0=rand(3,1),lb=zeros(3,1),ub=[10,20,30]);

Generate a random set of 40 points consistent with the problem.

points = list(rs,problem);

Examine the maximum and minimum generated components.

largest = max(max(points))

largest = 
29.8840

smallest = min(min(points))

smallest = 
0.1390

Update RandomStartPointSet

Create a RandomStartPointSet object that generates 50 points.

rs = RandomStartPointSet(NumStartPoints=50)

rs = 
  RandomStartPointSet with properties:

     NumStartPoints: 50
    ArtificialBound: 1000

Update rs to use 100 points and an artificial bound of 1e4.

rs = RandomStartPointSet(rs,NumStartPoints=100,ArtificialBound=1e4)

rs = 
  RandomStartPointSet with properties:

     NumStartPoints: 100
    ArtificialBound: 10000

You can also update properties using dot notation.

rs.ArtificialBound = 500

rs = 
  RandomStartPointSet with properties:

     NumStartPoints: 100
    ArtificialBound: 500

Version History

Introduced in R2010a