param eterとは 意味・読み方・使い方

語源

From French paramètre, from New Latin parametrum (“parameter”), from Ancient Greek παρα- (para-, “beside”) + μέτρον (métron, “measure”).

発音

• (英国発音) IPA: /pəˈɹæm.ɪ.tə/
• (米国発音) IPA: /pəˈɹæm.ə.tɚ/, [pəˈɹæm.ə.ɾɚ]
• (Indic) IPA: /parɑ.miʈə(r)/

名詞

parameter (plural parameters)

1. A value kept constant during an experiment, equation, calculation, or similar, but varied over other versions of the experiment, equation, calculation, etc.

   Coordinate terms: metaparameter, subparameter, superparameter

   • 2007, Charles M. Hansen, Hansen Solubility Parameters, →ISBN:

     As molecular surface-to-surface contacts control both solution phenomena and surface phenomena, it is not surprising that various correlations of cohesion parameters and surface phenomena can be found.

   • 2012, Kai-Sheng Lu, Rational Function Systems and Electrical Networks with Multi-Parameters, →ISBN:

     The independent parameters of a system or network over F(z) reflect its structure and determine its structural properties (such as the reducibility of coefficient matrix A and its characteristic polynomial det(λI −A), controllability and observability over F(z), etc.).

   • 2014, M. Amouroux, A. El Jai, Control of Distributed Parameter Systems 1989, →ISBN:

     On the other hand, if we have suitable data, we may be able to develop some direct computational methods for the essentially nonlinear parameter identification problems, in which fewer or even no nonlinear processes are involved.

2. (sciences) A variable that describes a property or characteristic of some system (material, object, event, etc.) or some aspect thereof.

   Coordinate terms: metaparameter, subparameter, superparameter, hyperparameter

   • 2007, Charles M. Hansen, Hansen Solubility Parameters: A User's Handbook, Second Edition, CRC Press, →ISBN, page 113:

     Cohesion parameters (solubility parameters) can be used with full theoretical justification to characterize many surfaces ...

   • 2012, Wolfgang Desch, Franz Kappel, Karl Kunisch, Control and Estimation of Distributed Parameter Systems: International Conference in Maria Trost (Austria), July 15–21, 2001, Birkhäuser, →ISBN, page 41:

     To this end, we derive an a posteriori error estimator for the error with respect to the unknown parameter.

   1. (statistics) Any measured quantity of a statistical population that summarises or describes an aspect of the population.
   2. (machine learning) A variable of a model that is trained by a machine learning algorithm.

      Coordinate term: feature

      • 2012, Michael Lemmon, Competitively Inhibited Neural Networks for Adaptive Parameter Estimation, Springer Science & Business Media, →ISBN, page 74:

        The parameter estimation problem considered in this chapter consists of estimating the unknown parameter, ū [a barred v, actually], given N samples of the observation process.

      • 2020 August 11, “The Guardian view on artificial intelligence's revolution: learning but not as we know it”, in The Guardian‎:

        Fundamental is the regulation of a for-profit OpenAI. The company initially delayed the launch of its earlier GPT-2, with a mere 1.5bn parameters, because the company fretted over its implications.

3. (programming) An input variable of a function definition, that gets an actual value (argument) at execution time.

   Synonym: formal parameter

4. (programming, loosely) An actual value given to such a formal parameter.

   Synonyms: argument, actual parameter

5. A characteristic or feature that distinguishes something from others.

   Synonyms: see Thesaurus:characteristic

6. (geometry) In the ellipse and hyperbola, a third proportional to any diameter and its conjugate, or in the parabola, to any abscissa and the corresponding ordinate.

   The parameter of the principal axis of a conic section is called the latus rectum.

7. (commutative algebra) Clipping of uniformizing parameter.
8. (crystallography) The ratio of the three crystallographic axes which determines the position of any plane.
9. (crystallography) The fundamental axial ratio for a given species.

使用する際の注意点

• (programming): Some authors regard use of parameter to mean argument as imprecise, preferring that parameter refers only to the name that will be instantiated, and argument to refer to the value that will be supplied to it at runtime.

派生語

関連する語

• parametric
• parametrise, parametrize

参考

• variable

Further reading

• “parameter”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “parameter”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.