array

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array

1. Maths a sequence of numbers or symbols in a specified order
2. Maths a set of numbers or symbols arranged in rows and columns, as in a determinant or matrix
3. Electronics an arrangement of aerials spaced to give desired directional characteristics, used esp in radar
4. Law a panel of jurors
5. Computing a regular data structure in which individual elements may be located by reference to one or more integer index variables, the number of such indices being the number of dimensions in the array

array

1. A system used in radio astronomy in which a number of discrete elements are connected to form a composite antenna. An element may for example be a single dipole or a dish. The ratio of the aperture area occupied by all the elements to the area that would be occupied by a continuous aperture of the same overall length is called the filling factor; it is a measure of the fraction of the aperture that is actually there. The effective area for an array operating at a wavelength λ with a directivity D is given by
A e = D λ2/4π

It is usually less than the physical area, even when the filling factor is equal to unity, because of small irregularities in the aperture distribution. For a perfect array with a uniform aperture distribution the effective and physical areas are indeed equal.

An array may produce a grating response in one or more directions away from the main lobe (see antenna) which, if the elements of the array were all nondirectional, would be as strong as the main lobe. However, the antenna patterns of the elements together with geometrical effects usually reduce the power in the grating response to an acceptable level. See also aperture synthesis; Butler matrix; feeder.

2. (detector array). An electronic device, such as a CCD, consisting of thousands or millions of individual detectors fabricated on centimeter-sized wafers of silicon or some other material.

array

[ə′rā]
(computer science)
A collection of data items with each identified by a subscript or key and arranged in such a way that a computer can examine the collection and retrieve data from these items associated with a particular subscript or key.
(electronics)
A group of components such as antennas, reflectors, or directors arranged to provide a desired variation of radiation transmission or reception with direction.
(statistics)
The arrangement of a sequence of items in statistics according to their values, such as from largest to smallest.

array

array
A stacked array of yagi antennas
A system of transmitting or receiving aerials made up of two or more identical aerials to give a greatly multiplied gain in desired direction. The aerials may be arranged in the direction of transmission (alignment array or endon array) or perpendicular to it (broadside array).
An array of four yagi antennas, if ideally spaced, will produce approximately 6 dB gain over a single yagi.

array

(programming)
A collection of identically typed data items distinguished by their indices (or "subscripts"). The number of dimensions an array can have depends on the language but is usually unlimited.

An array is a kind of aggregate data type. A single ordinary variable (a "scalar") could be considered as a zero-dimensional array. A one-dimensional array is also known as a "vector".

A reference to an array element is written something like A[i,j,k] where A is the array name and i, j and k are the indices. The C language is peculiar in that each index is written in separate brackets, e.g. A[i][j][k]. This expresses the fact that, in C, an N-dimensional array is actually a vector, each of whose elements is an N-1 dimensional array.

Elements of an array are usually stored contiguously. Languages differ as to whether the leftmost or rightmost index varies most rapidly, i.e. whether each row is stored contiguously or each column (for a 2D array).

Arrays are appropriate for storing data which must be accessed in an unpredictable order, in contrast to lists which are best when accessed sequentially. Array indices are integers, usually natural numbers, whereas the elements of an associative array are identified by strings.

array

(architecture)
A processor array, not to be confused with an array processor.

array

An ordered arrangement of data items. A vector is a one dimensional array; a matrix is a two-dimensional array. Arrays are used in myriad applications from basic database processing to scientific simulation. Most programming languages support arrays by providing indexes into the data. For example, with indexes starting at zero, the hypothetical programming statement Employee[4][9] points to the fifth record (row) and tenth data item (column) of an employee array. See subscript, index and data item.


Array Programming
With array indexes starting at 0, in the top array, City would be programmatically identified as Customer[3] (fourth data item). Sales[1][2] would refer to the March figures for Widgets in the bottom array.
References in periodicals archive ?
Antenna arrays are considered to be an important building block in many wireless applications such as radars, microwave imaging, satellite, and wireless communications.
The ultrasonic phased arrays are made from multiple ultrasonic elements.
This included a diffuser resonator array at the first and last stages of the compressor and a pipe resonator array installed on the inlet and discharge process piping.
Recently, an iterative fast Fourier transform (FFT) method [23] was presented to synthesize the large arrays with uniform element spacing.
Subspace Based Localization Method Using Small Aperture Arrays
Market Trend *The Introduction of COB LED arrays by Major Manufacturers
Coming soon to Office 365: Dynamic Arrays functions are expected to be released to all Office Insiders and Office 365 subscribers this year, perhaps even before this issue of the JofA hits mailboxes.
Phased arrays are now being used or proposed for use in internet of things (IoT) networks, high-speed back haul communication, terabit-per-second satellite systems, 5G mobile networks, and mobile phones.
Polymer lens arrays play crucial role in the optical components field.
Among these pattern recovery techniques, a popular one is the projection method (PM) that exploits only strain sensors and phase shifters to retrieve the main radiation properties of deformable arrays [1], thus avoiding the use of extensive signal processing, narrow-band correction algorithms, and potentially complex sensor networks that are instead required by more accurate and expensive solutions (e.g., mechanical [2] and electrical [3, 4] compensation).
GEM Energy, of the Rudolph Libbe Group in Walbridge, Ohio, is commencing construction on the second phase of Ohio Northern University's (ONU) solar initiative with a 1-megawatt solar array.
Cree, Inc announces the what it claims is the industry's first High-Density (HD) LED Arrays--a technology that is said to double the system intensity of spot lights compared to previous arrays. The new HD class of CXA Arrays provide desirable lumen density, enabling major reduction in system cost and power consumption, according to the company.