Login or Register to Ask a Question and Join Our Community

Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

qwtsamplingthread(3) [debian man page]

QwtSamplingThread(3)						 Qwt User's Guide					      QwtSamplingThread(3)

NAME

       QwtSamplingThread -

       A thread collecting samples at regular intervals.

SYNOPSIS

       #include <qwt_sampling_thread.h>

   Public Slots
       void setInterval (double interval)
       void stop ()

   Public Member Functions
       virtual ~QwtSamplingThread ()
       double interval () const
       double elapsed () const

   Protected Member Functions
       QwtSamplingThread (QObject *parent=NULL)
       virtual void run ()
       virtual void sample (double elapsed)=0

Detailed Description
       A thread collecting samples at regular intervals.

       Contiounous signals are converted into a discrete signal by collecting samples at regular intervals. A discrete signal can be displayed by
       a QwtPlotSeriesItem on a QwtPlot widget.

       QwtSamplingThread starts a thread calling perodically sample(), to collect and store ( or emit ) a single sample.

       See also:
	   QwtPlotCurve, QwtPlotSeriesItem

Constructor &; Destructor Documentation
   QwtSamplingThread::~QwtSamplingThread () [virtual]
       Destructor.

   QwtSamplingThread::QwtSamplingThread (QObject *parent = NULL) [explicit, protected]
       Constructor.

Member Function Documentation
   double QwtSamplingThread::elapsed () const Returns:
	   Time (in ms) since the thread was started

       See also:
	   QThread::start(), run()

   double QwtSamplingThread::interval () const Returns:
	   Interval (in ms), between 2 calls of sample()

       See also:
	   setInterval()

   void QwtSamplingThread::run () [protected, virtual] Loop collecting samples started from QThread::start()
       See also:
	   stop()

   virtual void QwtSamplingThread::sample (doubleelapsed) [protected, pure virtual] Collect a sample
       Parameters:
	   elapsed Time since the thread was started in miliseconds

   void QwtSamplingThread::setInterval (doubleinterval) [slot] Change the interval (in ms), when sample() is called. The default interval is
       1000.0 ( = 1s )
       Parameters:
	   interval Interval

       See also:
	   interval()

   void QwtSamplingThread::stop () [slot] Terminate the collecting thread
       See also:
	   QThread::start(), run()

Author
       Generated automatically by Doxygen for Qwt User's Guide from the source code.

Version 6.0.0							  Fri Apr 15 2011					      QwtSamplingThread(3)

Check Out this Related Man Page

QwtSystemClock(3)						 Qwt User's Guide						 QwtSystemClock(3)

NAME

       QwtSystemClock -

       QwtSystemClock provides high resolution clock time functions.

SYNOPSIS

       #include <qwt_system_clock.h>

   Public Member Functions
       QwtSystemClock ()
       virtual ~QwtSystemClock ()
       bool isNull () const
       void start ()
       double restart ()
       double elapsed () const

   Static Public Member Functions
       static double precision ()

Detailed Description
       QwtSystemClock provides high resolution clock time functions.

       Sometimes the resolution offered by QTime ( millisecond ) is not accurate enough for implementing time measurements ( f.e. sampling ).
       QwtSystemClock offers a subset of the QTime functionality using higher resolution timers ( if possible ).

       Precision and time intervals are multiples of milliseconds (ms).

       Note:
	   The implementation uses high-resolution performance counter on Windows, mach_absolute_time() on the Mac or POSIX timers on other
	   systems. If none is available it falls back on QTimer.

Constructor &; Destructor Documentation
   QwtSystemClock::QwtSystemClock ()
       Constructs a null clock object.

   QwtSystemClock::~QwtSystemClock () [virtual]
       Destructor.

Member Function Documentation
   double QwtSystemClock::elapsed () const Returns:
	   Number of milliseconds that have elapsed since the last time start() or restart() was called or 0.0 for null clocks.

   bool QwtSystemClock::isNull () const Returns:
	   true if the clock has never been started.

   double QwtSystemClock::precision () [static] Returns:
	   Accuracy of the system clock in milliseconds.

   double QwtSystemClock::restart () The start time to the current time and return the time, that is elapsed since the previous start time.
   void QwtSystemClock::start () Sets the start time to the current time.
Author
       Generated automatically by Doxygen for Qwt User's Guide from the source code.

Version 6.0.0							  Fri Apr 15 2011						 QwtSystemClock(3)
Man Page