| 释义 |
parameter
parametera measurable characteristic; a constant factor serving as a limit; guidelines: the basic parameters of our foreign policy
Not to be confused with:perimeter – the circumference or outline of a closed figure; outer boundary of an enclosed area: the perimeter of the estatepa·ram·e·ter P0061600 (pə-răm′ĭ-tər)n.1. Mathematics a. A constant in an equation that varies in other equations of the same general form, especially such a constant in the equation of a curve or surface that can be varied to represent a family of curves or surfaces.b. One of a set of independent variables that express the coordinates of a point.2. a. One of a set of measurable factors, such as temperature and pressure, that define a system and determine its behavior and are varied in an experiment.b. Usage Problem A factor that restricts what is possible or what results: "all the parameters of shelter—where people will live, what mode of housing they will choose, and how they will pay for it" (New York).c. A factor that determines a range of variations; a boundary: an experimental school that keeps expanding the parameters of its curriculum.3. Statistics A quantity, such as a mean, that is calculated from data and describes a population.4. Usage Problem A distinguishing characteristic or feature.
[New Latin parametrum, a line through the focus and parallel to the directrix of a conic : Greek para-, beside; see para-1 + Greek metron, measure; see -meter.]
par′a·met′ric (păr′ə-mĕt′rĭk), par′a·met′ri·cal adj.par′a·met′ri·cal·ly adv.Usage Note: The term parameter, which originates in mathematics, has a number of specific meanings in fields such as astronomy, electricity, crystallography, and statistics. Perhaps because of its ring of technical authority, people have applied parameter more generally in recent years to refer to any factor that determines a range of variations and especially to a factor that restricts what results from a process or policy. In this use, the word parameter is used to mean "the particular value of a parameter," and comes close to meaning "a set limit or boundary." For example, a budget can be thought of as a set of parameters that determine a range of activity, much like a set of mathematical parameters that establish the range of effects, or limits, of other variables. The sentence A budget is a framework that defines the financial parameters within which an organization operates was considered acceptable by 81 percent of the Usage Panel in our 2004 survey. Parameter is sometimes used incorrectly when it does not denote a range of variation, as if it were a technical-sounding synonym for characteristic. In 1988, 88 percent of the Usage Panel rejected the sentence The Judeo-Christian ethic is one of the important parameters of Western culture. In 2004, 77 percent rejected this same sentence, suggesting that familiarity has not bred tolerance of this usage.parameter (pəˈræmɪtə) n1. (Mathematics) one of a number of auxiliary variables in terms of which all the variables in an implicit functional relationship can be explicitly expressed. See parametric equations2. (Mathematics) a variable whose behaviour is not being considered and which may for present purposes be regarded as a constant, as y in the partial derivative ∂f(x,y)/∂x3. (Statistics) statistics a characteristic of the distribution of a population, such as its mean, as distinct from that of a sample. Compare statistic4. informal any constant or limiting factor: a designer must work within the parameters of budget and practicality. [C17: from New Latin; see para-1, -meter] parametric, ˌparaˈmetrical adjpa•ram•e•ter (pəˈræm ɪ tər)
n. 1. a. a constant or variable term in a mathematical function that determines the specific form of the function but not its general nature, as a in f(x)=ax, where a determines only the slope of the line described by f(x). b. one of the independent variables in a set of parametric equations. 2. a variable entering into the mathematical form of any statistical distribution such that the possible values of the variable correspond to different distributions. 3. a variable that must be given a specific value during the execution of either a computer program or a procedure within a program. 4. Usu., parameters. limits or boundaries; guidelines: to keep within the parameters of the discussion. 5. a determining characteristic; factor: a useful parameter for judging long-term success. [1650–60; < New Latin parametrum. See para-1, -meter] par•a•met•ric (ˌpær əˈmɛ trɪk) par`a•met′ri•cal, adj. usage: The use of parameter in the newer senses, “limits” or “characteristic” is often strongly criticized. Though the criticized uses are now well established both in educated speech and in edited writing, it is easy to substitute “limits” or “characteristics” if desired. pa·ram·e·ter (pə-răm′ĭ-tər) A quantity whose value can vary in general but is fixed when the quantity is used in a specific mathematical expression involving one or more other variables. For example, in finding the area of a circle, one needs to know the length of the circle's radius; that length is a parameter that will have different values for circles of different sizes.Thesaurus| Noun | 1. | parameter - a constant in the equation of a curve that can be varied to yield a family of similar curvesparametric quantityconstant, constant quantity, invariable - a quantity that does not varydegree of freedom - one of the minimum number of parameters needed to describe the state of a physical system | | 2. | parameter - any factor that defines a system and determines (or limits) its performancefactor - anything that contributes causally to a result; "a number of factors determined the outcome" | | 3. | parameter - (computer science) a reference or value that is passed to a function, procedure, subroutine, command, or programargumentvalue - a numerical quantity measured or assigned or computed; "the value assigned was 16 milliseconds"computer science, computing - the branch of engineering science that studies (with the aid of computers) computable processes and structuresaddress, computer address, reference - (computer science) the code that identifies where a piece of information is stored | | 4. | parameter - a quantity (such as the mean or variance) that characterizes a statistical population and that can be estimated by calculations from sample dataquantity - the concept that something has a magnitude and can be represented in mathematical expressions by a constant or a variable |
parameternoun (Informal) (usually plural) limit, constant, restriction, guideline, criterion, framework, limitation, specification We have to define the basic parameters within which we want to operate.Translationsalphaparamètreparametroпараметр
parameter
parameter1. one of a number of auxiliary variables in terms of which all the variables in an implicit functional relationship can be explicitly expressed 2. a variable whose behaviour is not being considered and which may for present purposes be regarded as a constant, as y in the partial derivative ∂f(x,y)/∂x Parameter a variable whose values are used to distinguish elements of a given set. For example, the equation (x — a)2 + (y — b)2 = 1 in rectangular Cartesian coordinates determines the set of all circles of radius 1 in the xOy plane. By setting a = 3 and b = 4, we isolate in this set the completely defined circle with center at (3, 4). Thus, a and b are the parameters of a circle in the set.
Parameter in engineering, a quantity that characterizes a certain aspect of a process, phenomenon, system, or device. Examples of such quantities in mechanical systems are mass, coefficient of friction, moment of inertia, and tension. Such parameters as heat capacity, heat flow, and thermal head are used for thermal processes. Typical electrical parameters are resistance, inductance, and capacitance. The physical processes that occur in a system are describable by equations giving the relation between the variable quantities of the processes. Parameters are usually the coefficients of the equations. They can be constants, or they can be variables dependent on time or the system’s coordinates. The parameters of a system or device can be lumped or they can be distributed in space relative to one, two, or three coordinates. A typical example of a system with distributed parameters is an electric power transmission line, in which the inductance, capacitance, and resistance (conductance) are distributed along the entire length of the line. An example of a lumped parameter is the load on a small segment of a much longer beam. M. M. MAIZEL’ parameter[pə′ram·əd·ər] (crystallography) Any of the axial lengths or interaxial angles that define a unit cell. (electricity) The resistance, capacitance, inductance, or impedance of a circuit element. The value of a transistor or tube characteristic. (mathematics) An arbitrary constant or variable so appearing in a mathematical expression that changing it gives various cases of the phenomenon represented. (physics) A quantity which is constant under a given set of conditions, but may be different under other conditions. parameter(1) Any value passed to a program by the user or by another program in order to configure the program for a particular purpose. A parameter may be anything; for example, a file name, a coordinate, a range of values, a money amount or a code of some kind. Parameters may be required as in parameter-driven software (see below) or they may be optional. Parameters are often entered as a series of values following the program name when the program is loaded; for example, a DOS switch defines a parameter. In the command dir /p the /p is a parameter switch that means pause after every screenful.
(2) In programming, a value passed to a subroutine or function for processing. Programming today's graphical applications in languages such as C, C++ and Java requires knowledge of hundreds of parameters.
In the following C function, which creates the text window for the Windows version of this database, there are 11 parameters passed to the CreateWindow routine. Some of them call yet other functions for necessary information. In order to call this routine in a program, the programmer must determine the values for every parameter.
hWndText = CreateWindow ( "TextWClass", NULL, WS_CHILD|WS_BORDER|WS_VSCROLL|WS_TABSTOP, xChar*23+GetSystemMetrics(SM_CXVSCROLL)+8, yChar*4, Rect.right-Rect.left+1-xChar*23 -2*GetSystemMetrics(SM_CXVSCROLL)+5, yChar*(Lines+1)+2, hWnd, IDC_TEXTLIST, (HANDLE)hInstance, NULL ); parameter
parameter [pah-ram´ĕ-ter] 1. in a mathematical expression, a constant that distinguishes specific cases, having a definite fixed value in one case but different values in other cases.2. in statistics, a value that specifies one of the members of a family of distributions" >probability distributions, such as the mean or the deviation" >standard deviation.3. a variable whose measure is indicative of a quantity or function that cannot itself be directly determined precisely.pa·ram·e·ter (pă-ram'ĕ-tĕr), Avoid the jargonistic use of this word to mean simply 'something measured or measurable'. One of many dimensions or ways of measuring or describing an object or evaluating a subject:1. In a mathematic expression, an arbitrary constant that can possess different values (with each value defining other expressions), and can thereby determine the specific form but not the general nature of the expression; for example, in the equation y = a + bx, a and b are parameters. 2. In statistics, a term used to define a characteristic of a population, in contrast to a sample from that population, for example, the mean and standard deviation of a total population. 3. In psychoanalysis, any tactic, other than interpretation, used by the analyst to further the patient's progress. [para- + G. metron, measure] parameter A mathematical and statistical variable in a model system that partially or completely characterises a probability distribution. Parameters are rarely known and are usually estimated by statistical computation from samples. In clinical trials, parameter may be used synonymously with variable for factual data—e.g., age, date of recovery, measurements and clinical assessments; however, it is most often linked to statistical conventions as a numeric characteristic of a population and thus has a narrower definition than variable.parameter Cardiac pacing A term quantifying an operational element determining pacemaker behavior–eg, rate, pulse width, A-V interval, refractory period, etcpa·ram·e·ter (pă-ram'ĕ-tĕr) 1. One of many dimensions or ways of measuring or describing an object or evaluating a subject 2. mathematics An arbitrary constant that can possess different values, each value defining other expressions. 3. statistics A term used to define a characteristic of a population, in contrast to a sample from that population. 4. psychoanalysis Any tactic, other than interpretation, used by the analyst to further the patient's progress. [para- + G. metron, measure]pa·ram·e·ter (pă-ram'ĕ-tĕr) One of many dimensions or ways of measuring or describing an object or evaluating a subject. [para- + G. metron, measure]Parameter
ParameterA model is a combination of variables, such as GDP growth, and coefficients which multiply these variables. The coefficients are often estimated from the data. The coefficients are called parameters.See PARM
See PARAMparameter
Synonyms for parameternoun limitSynonyms- limit
- constant
- restriction
- guideline
- criterion
- framework
- limitation
- specification
Synonyms for parameternoun a constant in the equation of a curve that can be varied to yield a family of similar curvesSynonymsRelated Words- constant
- constant quantity
- invariable
- degree of freedom
noun any factor that defines a system and determines (or limits) its performanceRelated Wordsnoun (computer science) a reference or value that is passed to a function, procedure, subroutine, command, or programSynonymsRelated Words- value
- computer science
- computing
- address
- computer address
- reference
noun a quantity (such as the mean or variance) that characterizes a statistical population and that can be estimated by calculations from sample dataRelated Words |