Amplitude: Difference between revisions

{{Short description|Measure of change in a periodic variable}}

{{About|amplitude in classical physics}}

 

The '''amplitude''' of a [[Periodic function|period]]ic [[Variable (mathematics)|variable]] is a measure of its change in a single [[Period (mathematics)|period]] (such as [[frequency|time]] or [[Wavelength|spatial period]]). The amplitude of a non-periodic signal is its [[Magnitude (mathematics)|magnitude]] compared with a reference value. There are various definitions of amplitude (see below), which are all [[function (mathematics)|function]]s of the magnitude of the differences between the variable's [[Maxima and minima|extreme values]]. In older texts, the [[Phase (waves)|phase]] of a periodic function is sometimes called the amplitude.<ref>{{Cite book | author1=Knopp, Konrad| author2= Bagemihl, Frederick | author-link1=Konrad Knopp | title=Theory of Functions Parts I and II | year=1996 | publisher=Dover Publications | isbn=978-0-486-69219-7 | page=3}}</ref>