- Waveform
**Waveform**means the shape and form of a signal such as awave moving in a solid, liquid or gaseous medium.In many cases the medium in which the wave is being propagated does not permit a direct visual image of the form. In these cases, the term 'waveform' refers to the shape of a graph of the varying quantity against time or distance. An instrument called an

oscilloscope can be used to pictorially represent the wave as a repeating image on a CRT or LCD screen.By extension of the above, the term 'waveform' is now also sometimes used to describe the shape of the graph of any varying quantity against time.

**Examples of waveforms**Common periodic waveforms include ("t" is time):

*

Sine wave : sin (2 π "t"). The amplitude of the waveform follows a trigonometric sine function with respect to time.

*Square wave : saw("t") − saw ("t" − duty). This waveform is commonly used to represent digital information. It is square wave of constant period contains odd harmonics that fall off at −6 dB/octave.

*Triangle wave : ("t" − 2 floor (("t" + 1) /2)) (−1)^{floor (("t" + 1) /2)}. This is theintegral of the square wave. It contains odd harmonics that fall off at −12 dB/octave.

*Sawtooth wave : 2 ("t" − floor("t")) − 1. This looks like the teeth of a saw. Found often intime base s for display scanning. It is used as the starting point forsubtractive synthesis , as a sawtooth wave of constant period contains odd and even harmonics that fall off at −6 dB/octave.Other waveforms are often called composite waveforms and can often be described as a combination of a number of sinusoidal waves or other

basis functions added together.The

Fourier series describes the decomposition of periodic waveforms, such that any periodic waveform can be formed by the sum of a fundamental component and harmonic components. Finite-energy non-periodic waveforms can be analyzed into sinusoids by theFourier transform .**ee also***

Sine wave

*Sawtooth wave

*Square wave

*Triangle wave

*Pulse wave

*WAV , an audio waveform file format

*Waveform monitor

*Waveform viewer

*Electronic tuner s measure waveforms**References****External links*** [

*http://www.floom.com/images/waveform_gallery.htm Waveform gallery*] of vocal sounds, including a stereo track

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