| 释义 |
discriminant, a. and n.|dɪˈskrɪmɪnənt|
[ad. L. discrīminānt-em, pr. pple. of discrīmināre to discriminate: see -ant1.]
A. adj.
1. Discriminating; showing discrimination or discernment.
1836Fraser's Mag. XIV. 411 Taylor's notes are not all so discriminant as this. 1866J. H. Newman Gerontius (1874) 334 With a sense so apprehensive and discriminant.
2. Math. Implying equal roots or a node (cf. B). discriminant relation, a one-fold relation between parameters determining a nodal point.
3. discriminant function, in Statistics, a function (usually linear) of a set of variables which is used to allocate items to any of several classes with minimum probability of misclassification, each variable taking one value for each item.
1936R. A. Fisher in Ann. Eugenics VII. 179 Discriminant functions. When two or more populations have been measured in several characters, x1,{ddd}, x8, special interest attaches to certain linear functions of the measurements by which the populations are best discriminated. 1948New Biol. IV. 43 The technique of discriminant functions is a means of finding the best combination of two or more measurable attributes for the distinction of two sub-classes of a population. 1962Lancet 15 Dec. 1238/2 To combine the information on prognosis derived from each of these compounds a simple combination of their values, known as a discriminant function, was calculated previously.
B. n. Math.
1. The eliminant of the n first derived functions of a homogeneous function of n variables.
Introduced in 1852 by Sylvester for determinant, which is still found occasionally (H. T. Gerrans).
1852Sylvester in Camb. & Dubl. Math. Jrnl. VI. 52. 1876 Salmon Mod. Higher Alg. (ed. 3) §109 The discriminant is equal to the product of the squares of all the differences of the differences of any two roots of the equation.
2. That which enables one to discriminate; a discriminating feature; spec. a discriminant function.
1920Expositor May 338 The formula ought not to be used as a discriminant between one Gospel and another. 1958New Scientist 16 Oct. 1083/2, I should like to suggest the word ‘determinant’ or possibly ‘discriminant’ [for the factors responsible for variance]. 1962Lancet 15 Dec. 1236/1 The discriminant has now been calculated for the normal women in this series. Ibid. 1239/2 Over half the patients..have negative discriminants. |