mrs_lib::MedianFilter Class Reference

Implementation of a median filter with a fixed-length buffer. More...

#include <median_filter.h>

Public Member Functions
	MedianFilter (const size_t buffer_length, const double min_value=-std::numeric_limits< double >::infinity(), const double max_value=std::numeric_limits< double >::infinity(), const double max_diff=std::numeric_limits< double >::infinity())
	The main constructor. More...
	MedianFilter ()
	A convenience empty constructor that will construct an invalid filter. More...
	MedianFilter (const MedianFilter &other)
	A convenience copy constructor. More...
	MedianFilter (MedianFilter &&other)
	A convenience move constructor. More...
MedianFilter &	operator= (const MedianFilter &other)
	A convenience copy assignment operator. More...
MedianFilter &	operator= (MedianFilter &&other)
	A convenience move assignment operator. More...
void	add (const double value)
	Add a new value to the buffer. More...
bool	check (const double value)
	Check whether a value complies with the constraints. More...
bool	addCheck (const double value)
	Add a new value to the buffer and check if it complies with the constraints. More...
void	clear ()
	Clear the buffer of all values. More...
bool	full () const
	Check whether the buffer is filled with values. More...
double	median () const
	Obtain the median. More...
bool	initialized () const
	Check whether the filter was initialized with a valid buffer length. More...
void	setBufferLength (const size_t buffer_length)
	Set a new size of the buffer. More...
void	setMinValue (const double min_value)
	Set a new minimal threshold for new values. More...
void	setMaxValue (const double max_value)
	Set a new maximal threshold for new values. More...
void	setMaxDifference (const double max_diff)
	Set a new maximal difference from median for new values. More...

Detailed Description

Implementation of a median filter with a fixed-length buffer.

Constructor & Destructor Documentation

MedianFilter() [1/4]

mrs_lib::MedianFilter::MedianFilter	(	const size_t	buffer_length,
		const double	min_value = -std::numeric_limits<double>::infinity(),
		const double	max_value = std::numeric_limits<double>::infinity(),
		const double	max_diff = std::numeric_limits<double>::infinity()
	)

The main constructor.

Parameters

buffer_length	the number of last values to be kept in the buffer.
min_value	values below this threshold will be discarded (won't be added to the buffer).
max_value	values above this threshold will be discarded.
max_diff	values that differ from the current mean by more than this threshold will be discarded.

MedianFilter() [2/4]

mrs_lib::MedianFilter::MedianFilter

(

)

A convenience empty constructor that will construct an invalid filter.

Warning

This constructor will construct an unusable filter with a zero-length buffer. To actually initialize this object, use the main constructor. You can use the initialized() method to check whether the object is valid.

MedianFilter() [3/4]

mrs_lib::MedianFilter::MedianFilter

(

const MedianFilter &

other

)

A convenience copy constructor.

This constructor copies all data from the object that is being assigned from in a thread-safe manner.

Parameters

other

the object to assign from.

MedianFilter() [4/4]

mrs_lib::MedianFilter::MedianFilter

(

MedianFilter &&

other

)

A convenience move constructor.

This constructor moves all data from the object that is being assigned from in a thread-safe manner, invalidating it.

Parameters

other

the object to assign from. It will be invalid after this method returns.

Member Function Documentation

add()

void mrs_lib::MedianFilter::add

(

const double

value

)

Add a new value to the buffer.

Note

The median value will not be updated until the median() method is called (lazy evaluation).

Parameters

value

the new value to be added to the buffer.

addCheck()

bool mrs_lib::MedianFilter::addCheck

(

const double

value

)

Add a new value to the buffer and check if it complies with the constraints.

The value is compliant if it's above the min_value, below the max_value and its (absolute) difference from the current mean is below max_diff.

Note

The median value will not be updated until the median() method is called (lazy evaluation).

Parameters

value

the new value to be added to the buffer and checked.

Returns

true if the value is compliant, false otherwise.

check()

bool mrs_lib::MedianFilter::check

(

const double

value

)

Check whether a value complies with the constraints.

The value is compliant if it's above the min_value, below the max_value and its (absolute) difference from the current mean is below max_diff.

Parameters

value

the value to be checked.

Returns

true if the value is compliant, false otherwise.

clear()

void mrs_lib::MedianFilter::clear

(

)

Clear the buffer of all values.

Doesn't change the buffer's length set in the constructor or any other parameters, only clears all stored values.

full()

bool mrs_lib::MedianFilter::full

(

)

const

Check whether the buffer is filled with values.

If true, adding a new value will remove the oldest value in the buffer.

Returns

true if the buffer contains buffer_length values.

initialized()

bool mrs_lib::MedianFilter::initialized

(

)

const

Check whether the filter was initialized with a valid buffer length.

Returns

true if the buffer length is larger than zero.

median()

double mrs_lib::MedianFilter::median

(

)

const

Obtain the median.

If an up-to-date median value is available, it's not recalculated. Otherwise, the new median value is calculated and then returned (lazy evaluation).

Returns

the current median value (returns nan if the input buffer is empty).

operator=() [1/2]

MedianFilter & mrs_lib::MedianFilter::operator=

(

const MedianFilter &

other

)

A convenience copy assignment operator.

This operator copies all data from the object that is being assigned from in a thread-safe manner.

Parameters

other

the object to assign from.

Returns

a reference to the object being assigned to.

operator=() [2/2]

MedianFilter & mrs_lib::MedianFilter::operator=

(

MedianFilter &&

other

)

A convenience move assignment operator.

This operator moves all data from the object that is being assigned from in a thread-safe manner, invalidating it.

Parameters

other

the object to assign from. It will be invalid after this method returns.

Returns

a reference to the object being assigned to.

setBufferLength()

void mrs_lib::MedianFilter::setBufferLength

(

const size_t

buffer_length

)

Set a new size of the buffer.

Note

The median value may change.

Parameters

buffer_length

the new size of the buffer.

setMaxDifference()

void mrs_lib::MedianFilter::setMaxDifference

(

const double

max_diff

)

Set a new maximal difference from median for new values.

Note

The current buffer is not changed - the change only applies to new values.

Parameters

max_diff

the new maximal difference of new buffer elements from the current median.

setMaxValue()

void mrs_lib::MedianFilter::setMaxValue

(

const double

max_value

)

Set a new maximal threshold for new values.

Note

The current buffer is not changed - the change only applies to new values.

Parameters

max_value

the new maximal value of new buffer elements.

setMinValue()

void mrs_lib::MedianFilter::setMinValue

(

const double

min_value

)

Set a new minimal threshold for new values.

Note

The current buffer is not changed - the change only applies to new values.

Parameters

min_value

the new minimal value of new buffer elements.

---

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

• include/mrs_lib/median_filter.h
• src/median_filter/median_filter.cpp