The amplitude of a periodic variable is a measure of its change over a single period (such as time or spatial period). There are various definitions of amplitude (see below), which are all functions of the magnitude of the difference between the variable's extreme values.
In older texts the phase is sometimes confusingly called the amplitude.
Famous quotes containing the word amplitude:
“Imagination, which in truth
Is but another name for absolute power
And clearest insight, amplitude of mind,
And reason, in her most exalted mood.”
—William Wordsworth (17701850)