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Arithmetic IF
The arithmetic IF statement is a three-way arithmetic conditional statement, first seen in the first release of Fortran in 1957, and found in all later versions, and some other programming languages, such as FOCAL. Unlike the logical IF statements seen in other languages, the Fortran statement defines three different branches depending on whether the result of an expression is negative, zero, or positive, in said order, written as: IF (expression) negative,zero,positive Deprecation While it originally was the only kind of IF statement provided in Fortran, the feature has been used less and less frequently after the logical IF statements were introduced, and was finally labeled obsolescent in Fortran 90. As of Fortran 2018, it is no longer required for compilers to implement arithmetic IF and it is considered to be a deleted feature. The GNU Fortran compiler has been producing warnings for arithmetic IF by default since its 9.1 release in 2019. See also * Sign functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conditional (programming)
In computer science, conditionals (that is, conditional statements, conditional expressions and conditional constructs,) are programming language commands for handling decisions. Specifically, conditionals perform different computations or actions depending on whether a programmer-defined boolean ''condition'' evaluates to true or false. In terms of control flow, the decision is always achieved by selectively altering the control flow based on some condition (apart from the case of branch predication). Although dynamic dispatch is not usually classified as a conditional construct, it is another way to select between alternatives at runtime. Terminology In imperative programming languages, the term "conditional statement" is usually used, whereas in functional programming, the terms "conditional expression" or "conditional construct" are preferred, because these terms all have distinct meanings. If–then(–else) The if–then construct (sometimes called if–then–els ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deprecation
In several fields, especially computing, deprecation is the discouragement of use of some terminology, feature, design, or practice, typically because it has been superseded or is no longer considered efficient or safe, without completely removing it or prohibiting its use. Typically, deprecated materials are not completely removed to ensure legacy compatibility or back up practice in case new methods are not functional in an odd scenario. It can also imply that a feature, design, or practice will be removed or discontinued entirely in the future. Etymology In general English usage, the infinitive "to deprecate" means "to express disapproval of (something)". It derives from the Latin verb ''deprecari'', meaning "to ward off (a disaster) by prayer". In current technical usage, for one to state that a feature is deprecated is merely a recommendation against using it. It is still possible to produce a program or product without heeding the deprecation. Software While a deprecated so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FOCAL (programming Language)
FOCAL (acronym for Formulating On-line Calculations in Algebraic Language, or FOrmula CALculator) is an interactive interpreted programming language based on ''JOHNNIAC Open Shop System'' (JOSS) and mostly used on Digital Equipment Corporation (DEC) Programmed Data Processor (PDP) series machines. FOCAL is very similar to JOSS in the commands it supports and the general syntax of the language. It differs in that many of JOSS' advanced features like ranges and user-defined functions were removed to simplify the parser. Some of the reserved words (keywords) were renamed so that they all start with a unique first letter. This allows users to type in programs using one-character statements, further reducing memory needs. This was an important consideration on the PDP-8, which was often limited to a few kilobytes (KB). Like JOSS, and later BASICs, FOCAL on the PDP-8 was a complete environment that included a line editor, an interpreter, and input/output routines. The package as a wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obsolescence
Obsolescence is the state of being which occurs when an object, service, or practice is no longer maintained or required even though it may still be in good working order. It usually happens when something that is more efficient or less risky replaces it. The international standard IEC 62402:2019 Obsolescence Management defines obsolescence as the "transition from available to unavailable from the manufacturer in accordance with the original specification". Obsolete also refers to something that is already disused or discarded, or antiquated. Typically, obsolescence is preceded by a gradual decline in popularity. Consequences Driven by rapid technological changes, new components are developed and launched on the market with increasing speed. The result is a dramatic change in production methods of all components and their market availability. A growing industry sector is facing issues where life cycles of products no longer fit together with life cycles of required components ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sign Function
In mathematics, the sign function or signum function (from '' signum'', Latin for "sign") is an odd mathematical function that extracts the sign of a real number. In mathematical expressions the sign function is often represented as . To avoid confusion with the sine function, this function is usually called the signum function. Definition The signum function of a real number is a piecewise function which is defined as follows: \sgn x :=\begin -1 & \text x 0. \end Properties Any real number can be expressed as the product of its absolute value and its sign function: x = , x, \sgn x. It follows that whenever is not equal to 0 we have \sgn x = \frac = \frac\,. Similarly, for ''any'' real number , , x, = x\sgn x. We can also ascertain that: \sgn x^n=(\sgn x)^n. The signum function is the derivative of the absolute value function, up to (but not including) the indeterminacy at zero. More formally, in integration theory it is a weak derivative, and in convex function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-way Comparison
In computer science, a three-way comparison takes two values A and B belonging to a type with a total order and determines whether A < B, A = B, or A > B in a single operation, in accordance with the mathematical law of trichotomy. Machine-level computation Many processors have instruction sets that support such an operation on primitive types. Some machines have signed integers based on a sign-and-magnitude or one's complement representation (see signed number representations), both of which allow a differentiated positive and negative zero. This does not violate trichotomy as long as a consistent total order is adopted: either −0 = +0 or −0 < +0 is valid. Common floating point types, however, have an exception to trichotomy: there is a special value "NaN" (Not a Number) such that ''x'' < NaN, ''x'' > NaN, and ''x'' = NaN are all false for all floating-point values ''x'' (including NaN itself). High-level languages Capabilities In C, the functions strcmp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conditional Constructs
Conditional (if then) may refer to: *Causal conditional, if X then Y, where X is a cause of Y *Conditional probability, the probability of an event A given that another event B has occurred *Conditional proof, in logic: a proof that asserts a conditional, and proves that the antecedent leads to the consequent *Strict conditional, in philosophy, logic, and mathematics *Material conditional, in propositional calculus, or logical calculus in mathematics * Relevance conditional, in relevance logic *Conditional (computer programming), a statement or expression in computer programming languages *A conditional expression in computer programming languages such as ?: *Conditions in a contract Grammar and linguistics *Conditional mood (or conditional tense), a verb form in many languages *Conditional sentence, a sentence type used to refer to hypothetical situations and their consequences **Indicative conditional, a conditional sentence expressing "if A then B" in a natural language **Cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
