QDaqVector Class Reference

A buffer for storing double numbers. More...

#include <QDaqVector.h>

Public Member Functions
	QDaqVector (int n=0)
	Create a buffer with n elements, initially filled with 0.
int	size () const
	Return the number of elememts stored in the buffer.
void	setSize (int n)
	set the size
bool	isCircular () const
	Return true if Circular.
void	setCircular (bool on)
	Set circular on or off.
int	capacity () const
	Return the currently allocated memory capacity (in number of elements).
void	setCapacity (int c)
	Set the capacity.
void	clear ()
	Empty the buffer.
double	get (int i) const
	Get the i-th element.
double	operator[] (int i) const
	Return the i-th element.
double &	operator[] (int i)
	Return the i-th element.
void	push (double v)
	Append a value to the buffer. More...
void	push (const double *v, int n)
	Append n values stored in memory location v to the buffer.
void	push (const QDaqVector &v)
	Append another vector.
void	pop ()
	Remove the last point.
QDaqVector &	operator<< (const double &v)
	Append a value to the buffer.
QDaqVector &	operator<< (const QDaqVector &v)
	Append another vector.
const double *	constData () const
	Return a const pointer to the data.
double *	data ()
	Return a pointer to the data.
double	vmin () const
	Minimum value in the buffer.
double	vmax () const
	Maximum value in the buffer.
double	mean () const
	Mean value in the buffer.
double	std () const
	Standard deviation the buffer values.

Detailed Description

A buffer for storing double numbers.

It is used for storing data from QDaqChannel objects.

The buffer has 3 modes, according to its StorageType property: it can be circular, i.e., new data overwrite old data, it can have fixed size or it can be expandable.

Data are inserted at the end of the buffer by the function push() or the operator<<(). The contents can be read by the function get() or the operator[](). The class provides read-only access to the data. It is not possible to change the value of a stored element.

The class defines functions for getting the min/max value, the mean and std deviation. The calculation of these quantities is stored internally and multiple calls to these functions do not cause a recalculation (except if the buffer contents have changed).

The buffer is explicitly shared, i.e., multiple instances share the same underlying data. This is used primarily for displaying real-time plots of data without copying the buffer.

Definition at line 40 of file QDaqVector.h.

Member Function Documentation

void QDaqVector::push ( double  v )

inline

Append a value to the buffer.

Pushing to a circular vector of 0 capacity 0 leads to an error.

Definition at line 86 of file QDaqVector.h.

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

• /home/george/Dev/rtlab/qdaq/lib/core/QDaqVector.h