casa::MedianSlider Class Reference [Mathematics_module]

Class to compute sliding median. More...

#include <MedianSlider.h>

List of all members.

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.
Float	add ()
	Adds a flagged datum.
Float	next (uInt n=1)
	Adds N flagged datums.
Float	add (const Vector< Float > &d, const Vector< Bool > &flag)
	Adds several datums at once (with corresponding flags).
Float	add (const Vector< Float > &d)
	Adds several non-flagged datums at once.
Int	nval ()
	Returns the number of values currently in the window.
Float	median ()
	Returns the current median value.
Float	prevVal (uInt n, Bool &flag)
	Returns a previous value (from n steps ago) from the sliding window.
Float	midpoint (Bool &flag)
	Returns value from midpoint (center) of window, possibly with flag.
Float	midpoint ()
Float	diff (Bool &flag)
	Returns the difference between the current median and the value at window center.
Float	diff ()
Bool	assure ()
	For testing purposes only: verifies current value of median.
Static Public Member Functions
static size_t	objsize (int halfwin)
	returns total memory usage (in bytes) for a given halfwin size
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 62 of file MedianSlider.h.

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Constructor & Destructor Documentation

casa::MedianSlider::MedianSlider

(

)

casa::MedianSlider::MedianSlider

(

int

halfwin

)

casa::MedianSlider::MedianSlider

(

const MedianSlider &

other

)

casa::MedianSlider::~MedianSlider

(

)

---

Member Function Documentation

Float casa::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 casa::MedianSlider::add

(

)

[inline]

Adds a flagged datum.

Definition at line 80 of file MedianSlider.h.

References add(), and casa::True.

Referenced by add().

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

Adds several datums at once (with corresponding flags).

Float casa::MedianSlider::add

(

const Vector< Float > &

d

)

Adds several non-flagged datums at once.

Bool casa::MedianSlider::assure

(

)

For testing purposes only: verifies current value of median.

Throws an exception if it fails.

void casa::MedianSlider::cleanup

(

)

Float casa::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 108 of file MedianSlider.h.

References median(), and midpoint().

Float casa::MedianSlider::diff

(

)

[inline]

Definition at line 109 of file MedianSlider.h.

References diff().

Referenced by diff().

Float casa::MedianSlider::median

(

)

[inline]

Returns the current median value.

return nind2 ? buf[ index[nind/2] ] : buf[ index[nind/2-1] ];

Definition at line 136 of file MedianSlider.h.

References buf, index, and nind.

Referenced by diff().

Float casa::MedianSlider::midpoint

(

Bool &

flag

)

[inline]

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

Definition at line 146 of file MedianSlider.h.

References halfwin, and prevVal().

Float casa::MedianSlider::midpoint

(

)

[inline]

Definition at line 103 of file MedianSlider.h.

References midpoint().

Referenced by diff(), and midpoint().

Float casa::MedianSlider::next

(

uInt

n = 1

)

Adds N flagged datums.

Int casa::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 131 of file MedianSlider.h.

References nind.

static size_t casa::MedianSlider::objsize

(

int

halfwin

)

[inline, static]

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

Definition at line 113 of file MedianSlider.h.

MedianSlider& casa::MedianSlider::operator=

(

const MedianSlider &

other

)

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

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

Referenced by midpoint().

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Member Data Documentation

Float* casa::MedianSlider::buf [private]

Definition at line 123 of file MedianSlider.h.

Referenced by median().

uInt casa::MedianSlider::fullwin [private]

Definition at line 122 of file MedianSlider.h.

uInt casa::MedianSlider::halfwin [private]

Definition at line 122 of file MedianSlider.h.

Referenced by midpoint().

uInt casa::MedianSlider::ibuf [private]

Definition at line 126 of file MedianSlider.h.

uInt* casa::MedianSlider::index [private]

Definition at line 124 of file MedianSlider.h.

Referenced by median().

uInt casa::MedianSlider::nind [private]

Definition at line 126 of file MedianSlider.h.

Referenced by median(), and nval().

Bool* casa::MedianSlider::valid [private]

Definition at line 125 of file MedianSlider.h.

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

• scimath/Mathematics/MedianSlider.h