Paraméter

Dina matématika, statistik, jeung matématika sains, paramétér (L: auxiliary measure) nyaéta kuantitas anu nangtukeun sababaraha sipat atawa karakteristik tina hiji sistim atawa fungsi matématis. Ilaharna dilambangkeun ku θ, atawa lambang séjén nu dianggap baku, atawa mibanda harti husus. Sabot ngévaluasi atawa ngitung fungsi ngaliwatan hiji domain atawa sabot nangtukeun réspon sistim dina hiji periode waktu ('hiji periode waktu' = tina hiji wanci ka wanci lain nu ditangtukeun), varibel bébas mah bisa robah-robah, tapi paramétér angger. Saterusna, fungsi atawa sistim bisa diévaluasi deui atawa diprosés deui maké paraméter nu béda, keur ngahasilkeun fungsi atawa sistim nu paripolahna béda.

'Paraméter-paraméter' (en: parameters), dina bentuk jamak, ayeuna jadi populér keur dipaké dina widang non-teknis nu nujul kana watesan-watesan, tapi ieu lain pikeun disalahartikeun atawa dipasaliakeun jeung kecap 'paraméter' dina harti téknis atawa widang téknik.

Conto

 In a section on frequently misused words in his book The Writer's Art, James J. Kilpatrick quoted a letter from a correspondent, giving examples to illustrate the correct use of the word parameter:

 A parametric equaliser is an audio filter that allows the frequency of maximum cut or boost to be set by one control, and the size of the cut or boost by another. These settings, the frequency level of the péak or trough, are two of the paraméters of a frequency response curve, and in a two-control equaliser they completely describe the curve. More elaborate parametric equalisers may allow other paraméters to be varied, such as skew. These paraméters éach describe some aspect of the response curve seen as a whole, over all frequencies.  A graphic equaliser provides individual level controls for various frequency bands, éach of which acts only on that particular frequency band.

Tipe parameter
Matematika
In mathematics, the difference in méaning between a parameter and an argument of a function is that the paraméters are the symbols that are part of the function's definition, while arguments are the symbols that are supplied to the function when it is used.  The value or objects assigned to the parameters by the corresponding arguments of a function or system are not réassigned during the function's evaluation.  So, paraméters are effectively constants during the evaluation or processing of that function or system.  The value of arguments can change outside of the function and between function usages.  This distinction, the paraméter's constancy, is a key part of the méaning of a paraméter in any situation, often in usage beyond just mathematics.

In some informal situations péople regard it as a matter of convention (and therefore a historical accident) whether some or all the arguments of a function are called paraméters.

Elmu komputer
When the terms formal paraméter and actual paraméter are used, they generally correspond with the definitions used in computer science.  In the definition of a function such as

f(x) = x + 2,

x is a formal paraméter. When the function is used as in

y = f(3) + 5,

3 is the actual paraméter value that is used to solve the equation. These concepts are discussed in a more precise way in functional programming and its foundational disciplines, lambda calculus and combinatory logic.

In computing, the paraméters passed to a function subroutine are more normally called arguments.

Logika
In logic, the paraméters passed to (or operated on by) an open predicate are called parameters by some authors (e.g., Prawitz, "Natural Deduction"; Paulson, "Designing a theorem prover"). Paraméters locally defined within the predicate are called variables. This extra distinction pays off when defining substitution (without this distinction special provision has to be made to avoid variable capture). Others (maybe most) just call paraméters passed to (or operated on by) an open predicate variables, and when defining substitution have to distinguish between free variables and bound variables.

Rekayasa
In engineering (especially involving data acquisition) the term parameter sometimes loosely refers to an individual méasured item. For example an airliner flight data recorder may record 88 different items, éach termed a paraméter. This usage isn't consistent, as sometimes the term channel refers to an individual méasured item, with parameter referring to the setup information about that channel.

Geometri analisa
Dina geometri, kurva bisa ngagambarkeun sababaraha fungsi. Alesan fungsi taya nu séjén disebut "parameter". Buleudan radius 1 tengahna bisa dituliskeun dina bentuk nu leuwih ti hiji bentuk: 
 bentuk implicit

 bentuk paraméter parametric

numana t nyaéta parameter.
Hal nu leuwih jéntré bisa kapanggih dina persamaan paramétrik.

Analisa matematika
In mathematical analysis, one often considers "integrals dependent on a parameter". These are of the form

In this formula, t is the argument of the function F on the left-hand side, and the parameter that the integral depends on, on the right-hand side. The quantity x is a dummy variable or variable (or parameter) of integration. Now, if we performed the substitution x=g(y), it would be called a change of variable.

Teori Probabilitas
In probability theory, one may describe the distribution of a random variable as belonging to a family of probability distributions, distinguished from éach other by the values of a finite number of parameters. For example, one talks about "a Poisson distribution with mean value λ", or "a normal distribution with mean μ and variance σ2". The latter formulation and notation léaves some ambiguity whether σ or σ2 is the second paraméter; the distinction is not always relevant.

It is possible to use the sequence of moments (méan, méan square, ...) or cumulants (méan, variance, ...) as paraméters for a probability distribution.

Statistika
Dina statistika, rarangkay gawe probabilitas di luhur masih kénéh dipaké, tapi museurkeun kana ngira-ngira paraméter sebaran dumasar kana tanpa nu ditempo, atawa tes hipotesis paraméterna. Dina estimasi klasik paraméter ieu dianggap "angger tapi teu dipikanyaho", tapi dina estimasti Bayes dianggap variabel acak nu sebaranna dianggap tina paraméter tadi.

Hal ieu ngamungkinkeun keur maké statistik inferen teu maké sabagéan kulawarga parameter sebaran distribusi. Dina kasus ieu, bisa disebutkeun yén statistik non parameter lawan tina statistik parametrik  nu bakal dijelaskeun dina paragrap saterusna. Contona, Spearman salah sahiji tes non-paraméter nu diitung tina runtuyan data bari teu merhatikun data nu sabenerna, sabalikna Pearson nyaete tes paraméter nu diitung langsung tina data jeung bisa dipaké nurunkeun hubungan matematisna.

Statistik nyaéta karakter matematika nu bisa dipaké keur ngira-ngira paraméter, populasi karakter matematika bisa digambarkeun tina sample nu dicokot. Contona, sample mean () bisa dipaké keur ngira-ngira mean paraméter (μ) tina populasi ku cara nyokot sampelna.

Tempo oge
Parametrization (i.e., coordinate system)
Parametrization (climate)
Parsimony (with regards to the trade-off of many or few paraméters in data fitting)

Kategori:Mathematical terminology