Editing Quadrature

{{wiktionary|quadrature}}

'''Quadrature''' may refer to:

== Mathematics ==
* [[Quadrature (geometry)]], drawing a square with the same area as a given plane figure (''squaring'') or computing that area
** [[Quadrature of the circle]]
** ''[[Quadrature of the Parabola]]''
** [[Quadrature of the hyperbola]]
* [[Numerical integration]] is often called "numerical quadrature" or simply "quadrature"
** [[Gaussian quadrature]], a special case of numerical integration
* [[Quadrature (differential equations)]], expressing a differential equation solution in terms of integrals.
* Formerly, a synonym for "integral"
** [[Integral]]
** [[Antiderivative]]

== Signal processing ==
* [[Addition in quadrature]], combining the magnitude of uncorrelated signals by taking the square root of the sum of their squares
*[[Quadrature phase]], oscillations that are said to be ''in quadrature'' if they are separated in phase by 90° ({{pi}}/2, or {{lambda}}/4)
*[[Quadrature component]] of a composite signal
*[[Quadrature filter]], the analytic signal of a real-valued filter
*[[Quadrature amplitude modulation]] (QAM), a modulation method of using both an (in-phase) carrier wave and a 'quadrature' carrier wave that is 90° out of phase with the main, or in-phase, carrier
*[[Quadrature phase-shift keying]] (QPSK), a phase-shift keying of using four quadrate points on the constellation diagram, equispaced around a circle

== Science ==
* [[Optical phase space#Quadratures|Optical phase space quadratures]], operators which represent the real and imaginary parts of the complex amplitude
* [[Quadrature (astronomy)]], the position of a body (moon or planet) such that its elongation is 90° or 270°; i.e., the body-earth-sun angle is 90°

== Other uses ==
* [[Quadrature encoder]], a device that detects mechanical position changes and direction of movement
* [[Illusionistic ceiling painting]], sometimes called ''quadrature'' after the Italian term, ''quadratura''
* [[La Quadrature du Net]] (Squaring of the Net in French), a French advocacy group that promotes digital rights and freedoms of citizens
* "Quadrature", a song by Squarepusher from the album ''[[Just a Souvenir]]''
{{disambiguation}}