1864 A. Cayley Coll. Math. Papers V. 552 μ is the parametric order, ν the parametric class, of the system.

1900 Trans. Amer. Math. Soc. 1 461 (heading) Parametric representation of the fundamental quadric.

1969 J. J. Stoker Differential Geom. ii. 14 Many important results in differential geometry can often be made direct and easy to achieve once a special parametric representation has been tactfully chosen.

1991 J. Hunt & D. Sturge in C. Bondi New Applic. Math. iv. 90 They use two simultaneous equations for x and y in terms of a parametric variable, t.

1942 J. Wolfowitz in Ann. Math. Statistics 13 264 Most of these developments have this feature in common, that the distribution functions of the various stochastic variables..are assumed to be of known functional form, and the theories of estimation and of testing hypotheses are theories of estimation of and of testing hypotheses about, one or more parameters..the knowledge of which would completely determine the various distribution functions involved. We shall refer to this situation..as the parametric case.

1962 E. S. Keeping Introd. Statistical Inference x. 251 In those cases where a parametric test would also be applicable a non-parametric test will naturally be less powerful than the parametric one.

1991 S. Faludi Backlash i. ii. 10 Princeton professors..had originally constructed the parametric model to analyze marital patterns of elderly women who had already completed their marriage cycle.

1996 Q. Jrnl. Royal Astron. Soc. 37 525 The standard parametric test assumes that the variables (x_i, y_i) are Normally distributed.

1957 RCA Rev. 18 578 (heading) Theory of parametric amplification using nonlinear reactances.

1968 D. J. Angelakos & T. E. Everhart Microwave Communications iv. 82 A parametric amplifier converts power at one frequency (from a source generally called the pump) into power at another frequency, the signal frequency... The pump voltage is mixed with the signal voltage by a nonlinear reactance, which in microwave systems is generally a varactor diode.

1971 Physics Bull. Aug. 464/3 Parametric conversions of waves to other frequencies are familiar in the field of non~linear optics.

1973 F. Zernike & J. E. Midwinter Appl. Nonlinear Optics vii. 153 The parametric up-converter is a special case of sum-frequency generation. Similarly, the parametric amplifier and the parametric oscillator are special cases of difference-frequency generation.

1982 Giant Bk. Electronics Projects x. 474 These klystrons have found applications..as pump oscillators for amateur and commercial parametric amplifiers.

1998 Nature 12 Nov. 149/2 The Mathieu equation governs..the behaviour of parametric amplifiers based on electronic or super-conducting devices.

1873 G. Salmon Treat. Higher Plane Curves 65 When the variable curve depends on a parametric point moving on a given parametric curve.

1909 L. P. Eisenhart Treat. Differential Geom. Curves & Surfaces ii. 55 Upon a surface (2) there lie an infinity of curves whose equations are given by equations (2), when u is constant, each constant value of v determining a curve... In a similar way, there is an infinite family of curves v = const. The curves of these two families are called the parametric curves for the given equations of the surface.

1983 W. R. Uttal Visual Form Detection in 3-dimensional Space iii. 59 The three parametric curves in each of these figures represent the data obtained for the three viewing conditions (dichoptic, left monocular, and right monocular) on three successive days.

1980 Musicians Only 26 Apr. 12 Parametric equalisers, graphics can have their frequency fixed, but parametrics roam.

1985 Internat. Musician June 24/1 A simple parametric equaliser usually has only two filters that you can manually tune up and down the frequency range.

1996 Macweek (Nexis) 9 Sept. 66 The program does..have strong real-time signal-processing features, including four parametric equalizers per channel.

1902 Trans. Amer. Math. Soc. 3 442 The parametric equation of the involution will be [etc.].

1942 C. H. Lehmann Analyt. Geom. xi. 230 Find the rectangular equation of the curve whose parametric equations are x = 2 + 3 tan θ, y = 1 + 4 sec θ.

1993 Harper's Mag. Sept. 72/2 But since here, on my bedroom's floor, a circle was rolling around what was itself the circumference of a circle, the cycloid's standard parametric equations were no longer applicable.

1871 Proc. Royal Soc. 1870–71 19 460 The preceding data lead to the parametrical proportion a:b:c=1·003:1:1·375, not very far different from a pyramidal axial proportion.

1887 R. A. Roberts Integral Calculus I. 301 These angles belong to different parametrical systems.

1995 Proc. Royal Soc. A. 448 469 The parametrical angle α generally differs from the polar angle θ.

1883 J. M. Duncan Clin. Lect. Dis. Women (ed. 2) xi. 96 The inflammatory disease is generally parametric.

1897 R. W. Garrett Text Bk. Med. & Surg. Gynæcol. 104 Good results often follow the adoption of this treatment in old parametric and perimetric exudates.