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Enumerator
Enumerator may refer to: *Iterator (computer science) * An enumerator in the context of iteratees *in computer programming, a value of an enumerated type * Enumerator (computer science), a Turing machine that lists elements of some set S. *a census taker, a person performing door-to-door around census A census is the procedure of systematically acquiring, recording and calculating information about the members of a given population. This term is used mostly in connection with national population and housing censuses; other common censuses in ..., to count the people and gather demographic data. *a person employed in the counting of votes in an election. * Enumerator polynomial {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iterator
In computer programming, an iterator is an object that enables a programmer to traverse a container, particularly lists. Various types of iterators are often provided via a container's interface. Though the interface and semantics of a given iterator are fixed, iterators are often implemented in terms of the structures underlying a container implementation and are often tightly coupled to the container to enable the operational semantics of the iterator. An iterator performs traversal and also gives access to data elements in a container, but does not itself perform iteration (i.e., not without some significant liberty taken with that concept or with trivial use of the terminology). An iterator is behaviorally similar to a database cursor. Iterators date to the CLU programming language in 1974. Description Internal Iterators Internal iterators are higher order functions (often taking anonymous functions, but not necessarily) such as map(), reduce() etc., implementing the trav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enumerator (computer Science)
An enumerator is a Turing machine with an attached printer. The Turing machine can use that printer as an output device to print strings. Every time the Turing machine wants to add a string to the list, it sends the string to the printer. Enumerator is a type of Turing machine variant and is equivalent with Turing machine. Formal definition An enumerator E can be defined as a 2-tape Turing machine (Multitape Turing machine A multi-tape Turing machine is a variant of the Turing machine that utilizes several tapes. Each tape has its own head for reading and writing. Initially, the input appears on tape 1, and the others start out blank. This model intuitively seems m ... where k=2 ) whose language is \empty. Initially, E receives no input, and all the tapes are blank (i.e., filled with blank symbols). Newly defined symbol \#\in \Gamma\land\#\notin \Sigma is the delimiter that marks end of an element of S. The second tape can be regarded as the printer, strings on it are separat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iteratee
In functional programming, an iteratee is a composable abstraction for incrementally processing sequentially presented chunks of input data in a purely functional fashion. With iteratees, it is possible to lazily transform how a resource will emit data, for example, by converting each chunk of the input to uppercase as they are retrieved or by limiting the data to only the five first chunks without loading the whole input data into memory. Iteratees are also responsible for opening and closing resources, providing predictable resource management. On each step, an iteratee is presented with one of three possible types of values: the next chunk of data, a value to indicate no data is available, or a value to indicate the iteration process has finished. It may return one of three possible types of values, to indicate to the caller what should be done next: one that means "stop" (and contains the final return value), one that means "continue" (and specifies how to continue), and one t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Census
A census is the procedure of systematically acquiring, recording and calculating information about the members of a given population. This term is used mostly in connection with national population and housing censuses; other common censuses include censuses of agriculture, traditional culture, business, supplies, and traffic censuses. The United Nations (UN) defines the essential features of population and housing censuses as "individual enumeration, universality within a defined territory, simultaneity and defined periodicity", and recommends that population censuses be taken at least every ten years. UN recommendations also cover census topics to be collected, official definitions, classifications and other useful information to co-ordinate international practices. The UN's Food and Agriculture Organization (FAO), in turn, defines the census of agriculture as "a statistical operation for collecting, processing and disseminating data on the structure of agriculture, covering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enumerated Type
In computer programming, an enumerated type (also called enumeration, enum, or factor in the R programming language, and a categorical variable in statistics) is a data type consisting of a set of named values called ''elements'', ''members'', ''enumeral'', or ''enumerators'' of the type. The enumerator names are usually identifiers that behave as constants in the language. An enumerated type can be seen as a degenerate tagged union of unit type. A variable that has been declared as having an enumerated type can be assigned any of the enumerators as a value. In other words, an enumerated type has values that are different from each other, and that can be compared and assigned, but are not specified by the programmer as having any particular concrete representation in the computer's memory; compilers and interpreters can represent them arbitrarily. For example, the four suits in a deck of playing cards may be four enumerators named ''Club'', ''Diamond'', ''Heart'', and ''Spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demographic
Demography () is the statistical study of populations, especially human beings. Demographic analysis examines and measures the dimensions and dynamics of populations; it can cover whole societies or groups defined by criteria such as education, nationality, religion, and ethnicity. Educational institutions usually treat demography as a field of sociology, though there are a number of independent demography departments. These methods have primarily been developed to study human populations, but are extended to a variety of areas where researchers want to know how populations of social actors can change across time through processes of birth, death, and migration. In the context of human biological populations, demographic analysis uses administrative records to develop an independent estimate of the population. Demographic analysis estimates are often considered a reliable standard for judging the accuracy of the census information gathered at any time. In the labor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
