| 释义 |
iteration|ɪtəˈreɪʃən|
Also 6 yt-, itt-.
[ad. L. iterātiōn-em, n. of action from iterāre to iterate. Cf. F. itération (1488 in Godef.).]
The action of iterating or repeating, or process of being iterated.
1. a. Repetition of an action or process (now usually implying frequency or long continuance); repeated performance; an instance of this. Formerly said esp. of readministering a sacrament.
1477Norton Ord. Alch. vi. in Ashm. (1652) 100 The multitude of their Iteration. 1550Bale Apol. 18 Than grewe it into a name and use amonge that sort (as amonge the sectes of owr tyme the iteracyon of baptysme). 1694Salmon Bate's Dispens. (1713) 431/2 For three or four Iterations, the Regulus becomes apparently more bright and pure. 1790Paley Horæ Paul. (1825) 159 The rules of good writing taught the ear to be offended with the iteration of the same sound. 1845S. Austin Ranke's Hist. Ref. I. 3 The lifeless iteration of misunderstood doctrines and rites, which kill the soul. 1872W. Minto Eng. Prose Lit. Introd. 30 A person of strong tender feeling is not easily offended by the iteration of pathetic images.
b. Math. The repetition of an operation upon its product, as in finding the cube of a cube; esp. the repeated application of a formula devised to provide a closer approximation to the solution of a given equation when an approximate solution is substituted in the formula, so that a series of successively closer approximations may be obtained; a single application of such a formula; also, the formula itself.
1901in N.E.D. 1924Whittaker & Robinson Calculus of Observations vi. 79 In 1674 a method depending on a new principle, the principle of iteration, was communicated in a letter from Gregory to Collins. 1941Phil. Mag. XXXII. 374 After a few iterations the values of er much less than unity will hardly affect the results. 1960G. N. Lance Numerical Methods for High Speed Computers i. 8 Whichever criterion is used to determine the end of the iteration, it is clear that the orders to evaluate f(xr) and f(xr + 1) are identical except that xr + 1 is used instead of xr. This kind of modification is made extremely simple on high-speed computers. 1968E. T. Copson Metric Spaces viii. 115 The Newton-Raphson iteration xn + 1 = xn - f(xn)/f′(xn) for solving the equation f(x) = 0.
c. Roman Law. (See quot.)
1880Muirhead Ulpian iii. §4 By iteration he becomes a Roman citizen who, having been made a latin after he had passed the age of thirty, is anew formally manumitted by the person who had the quiritarian right in him when a slave.
2. The repetition of something said; repeated utterance or assertion.
1530Palsgr. 333 After yteracyons of the pronowne they use ever moij. 1556J. Heywood Spider & F. Concl. 50 Tedius Iteration therof I let passe. 1634Heywood & Brome Witches Lanc. iv. H.'s Wks. 1874 IV. 228, I will not aggravate thy griefe too much, By needles iteration. 1759Johnson Idler No. 77 ⁋2 Any curious iteration of the same word. 1886Manch. Exam. 29 Jan. 5/2 The House was told with suspicious iteration that the Government had nailed their colours to the mast. |