casacore::MedianSlider Class Reference

Class to compute sliding median. More...

#include <MedianSlider.h>

Public Member Functions
	MedianSlider ()
	MedianSlider (int halfwin)
	MedianSlider (const MedianSlider &other)
	~MedianSlider ()
MedianSlider &	operator= (const MedianSlider &other)
void	cleanup ()
Float	add (Float d, Bool flag=False)
	Adds a datum to the slider. More...
Float	add ()
	Adds a flagged datum. More...
Float	next (uInt n=1)
	Adds N flagged datums. More...
Float	add (const Vector< Float > &d, const Vector< Bool > &flag)
	Adds several datums at once (with corresponding flags) More...
Float	add (const Vector< Float > &d)
	Adds several non-flagged datums at once. More...
Int	nval ()
	Returns the number of values currently in the window. More...
Float	median ()
	Returns the current median value. More...
Float	prevVal (uInt n, Bool &flag)
	Returns a previous value (from n steps ago) from the sliding window. More...
Float	midpoint (Bool &flag)
	Returns value from midpoint (center) of window, possibly with flag. More...
Float	midpoint ()
Float	diff (Bool &flag)
	Returns the difference between the current median and the value at window center. More...
Float	diff ()
Bool	assure ()
	For testing purposes only: verifies current value of median. More...

Static Public Member Functions
static size_t	objsize (int halfwin)
	returns total memory usage (in bytes) for a given halfwin size More...

Private Attributes
uInt	halfwin
uInt	fullwin
Float *	buf
uInt *	index
Bool *	valid
uInt	ibuf
uInt	nind

Detailed Description

Class to compute sliding median.

Intended use:

Public interface

Review Status

Date Reviewed:

yyyy/mm/dd

Synopsis

MedianSlider is a class for efficient computing of sliding medians.

Example

Motivation

Flagging Agents make extended use of sliding medians.

To Do

• think about a 2D sliding median

Definition at line 64 of file MedianSlider.h.

Constructor & Destructor Documentation

casacore::MedianSlider::MedianSlider

(

)

Referenced by objsize().

casacore::MedianSlider::MedianSlider

(

int

halfwin

)

casacore::MedianSlider::MedianSlider

(

const MedianSlider &

other

)

casacore::MedianSlider::~MedianSlider

(

)

Member Function Documentation

Float casacore::MedianSlider::add	(	Float	d,
		Bool	flag = False
	)

Adds a datum to the slider.

Once the window is full, newer values will push out older values. Returns the new median value. If flag is set to true, adds a "flagged" datum, one which takes up space in the window but is skipped during median computations.

Float casacore::MedianSlider::add ( )

inline

Adds a flagged datum.

Definition at line 82 of file MedianSlider.h.

References add(), and casacore::True.

Referenced by add().

Float casacore::MedianSlider::add	(	const Vector< Float > &	d,
		const Vector< Bool > &	flag
	)

Adds several datums at once (with corresponding flags)

Float casacore::MedianSlider::add

(

const Vector< Float > &

d

)

Adds several non-flagged datums at once.

Bool casacore::MedianSlider::assure

(

)

For testing purposes only: verifies current value of median.

Throws an exception if it fails.

void casacore::MedianSlider::cleanup

(

)

Float casacore::MedianSlider::diff ( Bool &  flag )

inline

Returns the difference between the current median and the value at window center.

Optionally, also returns flag of median center

Definition at line 110 of file MedianSlider.h.

References median(), and midpoint().

Float casacore::MedianSlider::diff ( )

inline

Definition at line 111 of file MedianSlider.h.

Float casacore::MedianSlider::median ( )

inline

Returns the current median value.

return nind%2 ? buf[ index[nind/2] ] : buf[ index[nind/2-1] ];

Definition at line 138 of file MedianSlider.h.

References buf, index, and nind.

Referenced by diff().

Float casacore::MedianSlider::midpoint ( Bool &  flag )

inline

Returns value from midpoint (center) of window, possibly with flag.

Definition at line 148 of file MedianSlider.h.

References halfwin, and prevVal().

Float casacore::MedianSlider::midpoint ( )

inline

Definition at line 105 of file MedianSlider.h.

Referenced by diff().

Float casacore::MedianSlider::next

(

uInt

n = 1

)

Adds N flagged datums.

Int casacore::MedianSlider::nval ( )

inline

Returns the number of values currently in the window.

This is less than the window width initially. Int size ();

Returns the number of non-flagged values in window

Definition at line 133 of file MedianSlider.h.

References nind.

static size_t casacore::MedianSlider::objsize ( int  halfwin )

inlinestatic

returns total memory usage (in bytes) for a given halfwin size

Definition at line 115 of file MedianSlider.h.

References MedianSlider().

MedianSlider& casacore::MedianSlider::operator=

(

const MedianSlider &

other

)

Float casacore::MedianSlider::prevVal	(	uInt	n,
		Bool &	flag
	)

Returns a previous value (from n steps ago) from the sliding window.

Referenced by midpoint().

Member Data Documentation

Float* casacore::MedianSlider::buf

private

Definition at line 125 of file MedianSlider.h.

Referenced by median().

uInt casacore::MedianSlider::fullwin

private

Definition at line 124 of file MedianSlider.h.

uInt casacore::MedianSlider::halfwin

private

Definition at line 124 of file MedianSlider.h.

Referenced by midpoint().

uInt casacore::MedianSlider::ibuf

private

Definition at line 128 of file MedianSlider.h.

uInt* casacore::MedianSlider::index

private

Definition at line 126 of file MedianSlider.h.

Referenced by median().

uInt casacore::MedianSlider::nind

private

Definition at line 128 of file MedianSlider.h.

Referenced by median(), and nval().

Bool* casacore::MedianSlider::valid

private

Definition at line 127 of file MedianSlider.h.

---

The documentation for this class was generated from the following file:

• casa/casacore/scimath/Mathematics/MedianSlider.h