uk.ac.starlink.ttools.scheme

Class AttractorScheme

java.lang.Object

uk.ac.starlink.ttools.scheme.AttractorScheme

All Implemented Interfaces:

Documented, TableScheme

public class AttractorScheme
extends Object
implements TableScheme, Documented

TableScheme that can produce tables representing a sequence of 2d or 3d points in space corresponding to iterated sequence that follow (strange) attractors. This can be useful for generating large tables with non-trivial content columns (X,Y) or (X,Y,Z), especially for plotting demos.

Currently three attractor types are supported, as documented in the usage string. An example specification would be something like

    attractor:1e7,clifford,-1.25,1.66,-1.79,-0.25
 

where the first number is row count, the name is one of the supported attractor types, and the numbers are parameters to that attractor. The number of parameters depends on the type, but if no numbers are supplied, then an example set is used. Note if you supply parameters at random you have a good chance of getting a boring (non-strange) attractor.

Since:

20 Jul 2020

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
AttractorScheme()

Method Summary

Modifier and Type	Method and Description
StarTable	createTable(String argtxt) Turns a scheme-specific specification into a table.
String	getExampleSpecification() Returns a scheme-specific specification string suitable for use in examples.
String	getSchemeName() Returns the name of this scheme.
String	getSchemeUsage() Returns a short, plain-text usage string.
String	getXmlDescription() Returns user-directed documentation in XML format.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AttractorScheme

public AttractorScheme()

Method Detail

getSchemeName

public String getSchemeName()

Description copied from interface: TableScheme

Returns the name of this scheme. This string must be alphanumeric and should be short. It will be used between the colons in a table specification.

Specified by:

getSchemeName in interface TableScheme

Returns:

scheme name

getSchemeUsage

public String getSchemeUsage()

Description copied from interface: TableScheme

Returns a short, plain-text usage string. This should just represent the legal syntax for the specification string.

Specified by:

getSchemeUsage in interface TableScheme

Returns:

usage syntax

getExampleSpecification

public String getExampleSpecification()

Description copied from interface: TableScheme

Returns a scheme-specific specification string suitable for use in examples. It should return a table short enough to appear in textual documentation. If no suitable example is available, null may be returned.

Specified by:

getExampleSpecification in interface TableScheme

Returns:

scheme-specific specification (scheme name part not included), or null

getXmlDescription

public String getXmlDescription()

Description copied from interface: Documented

Returns user-directed documentation in XML format.

The output should be a sequence of one or more <P> elements, using XHTML-like XML. Since rendering may be done in a number of contexts however, use of the full range of XHTML elements is discouraged. Where possible, the content should stick to simple markup such as the elements P, A, UL, OL, LI, DL, DT, DD EM, STRONG, I, B, CODE, TT, PRE.

Specified by:

getXmlDescription in interface Documented

Returns:

XML description of this object

createTable

public StarTable createTable(String argtxt)
                      throws TableFormatException

Description copied from interface: TableScheme

Turns a scheme-specific specification into a table. In case of any error, an exception should be thrown.

Specified by:

createTable in interface TableScheme

Parameters:

argtxt - scheme-specific table specification (scheme name part is not included)

Returns:

created table, not null

Throws:

TableFormatException - if the format of the specification is syntactically incorrect (will typically provoke an error containing the schemeUsage string)