uk.ac.starlink.ttools.filter

Class StatsFilter

java.lang.Object

uk.ac.starlink.ttools.filter.BasicFilter

uk.ac.starlink.ttools.filter.StatsFilter

All Implemented Interfaces:

ProcessingFilter

public class StatsFilter
extends BasicFilter

Filter which can calculate statistical quantities.

Since:

26 Apr 2006

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
StatsFilter() Constructor.

Method Summary

Modifier and Type	Method and Description
ProcessingStep	createStep(Iterator<String> argIt) Creates a new ProcessingStep based on a sequence of command-line arguments.
protected String[]	getDescriptionLines()
static double	parseQuantileSpecifier(String txt) Parses a string that represents an arbitrary quantile.

Methods inherited from class uk.ac.starlink.ttools.filter.BasicFilter

explainSyntax, getDescription, getName, getUsage

Methods inherited from class java.lang.Object

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

Constructor Detail

StatsFilter

public StatsFilter()

Constructor.

Method Detail

getDescriptionLines

protected String[] getDescriptionLines()

Specified by:

getDescriptionLines in class BasicFilter

createStep

public ProcessingStep createStep(Iterator<String> argIt)
                          throws ArgException

Description copied from interface: ProcessingFilter

Creates a new ProcessingStep based on a sequence of command-line arguments. The argIt argument is an iterator over the command-line arguments positioned just before any arguments intended for this filter. If legal, any that can be comprehended by this filter should be read (iterated over) and removed, and a ProcessingStep should accordingly be returned. In the case of a successful return, it is essential that no arguments other than the ones intended for this filter are read from the iterator.

If the argument list is badly-formed as far as this filter is concerned, an ArgException should be thrown.

Parameters:

argIt - iterator over command-line arguments positioned at the first one

Throws:

ArgException

parseQuantileSpecifier

public static double parseQuantileSpecifier(String txt)

Parses a string that represents an arbitrary quantile. This is of the form Q.xxx, where xxx is the quantile fraction, so for instance "Q.01" is the first percentile and "Q.4" is the 40th percentile.

Parameters:

txt - text which may represent a quantile specifier

Returns:

value in the range 0..1 giving the quantile level, or NaN if it's not a quantile specifier