| 释义 |
periodogram|pɪərɪˈɒdəgræm|
[f. period n. + -o + -gram.]
A diagram or method of graphical representation which is designed to detect or display any periodicity (usu. with time) in a set of measurements of a quantity; spec. one in which the results of harmonic analysis of the data, performed on the assumption in turn of different periods of variation, are plotted as a function of the period. Freq. attrib., as periodogram analysis, the analysis of data by means of a periodogram.
1898A. Schuster in Terrestr. Magn. III. 24 It is convenient to have a word for some representation of a variable quantity which shall correspond to the ‘spectrum’ of a luminous radiation. I propose the word periodogram. Ibid. 25 The periodogram of the sound emitted by an organ pipe or a violin string consists of a series of equidistant ‘lines’. 1906Proc. R. Soc. A. LXXVII. 141 The periodigram..is the diagram representing the intensity of periodic variations as determined from the sum of the squares of the two Fourier coefficients belonging to each assumed period. 1919Nature 26 June 338/1 A periodogram analysis of the Greenwich temperature records. 1939J. A. Schumpeter Business Cycles I. iv. 165 This is the most successful application so far made of the periodogram analysis to economic data. 1957G. E. Hutchinson Treat. Limnol. I. v. 334 Olson (1950) examined the matter by means of periodogram analysis and found no evidence of a period near 12 hours. 1974Nature 8 Feb. 339/3 The apparently erratic optical fluctuations have been analysed by various investigators using power spectra and the so-called periodogram techniques. |