What is iteration in computer science. Project development

iteration (iteratio; lat. repetition) in psychiatry

pathological agitation, characterized by a tendency to repeat the same movement or complex motor act, word, part of a phrase, etc., without noticeable emotional overtones of the actions performed.

Encyclopedic Dictionary, 1998

iteration

ITERATION (from Latin iteratio - repetition) repeated application of any mathematical operation.

Iteration

(from Latin iteratio ≈ repetition) in mathematics, the result of repeated application of any mathematical operation. So, if y = f (x) º f1(x) is some function of x, then the functions f2(x) = f, f3(x) = f,..., fn (x) = f are called the second, respectively, the third,..., nth iterations of the function f (x). For example, putting f (x) = xa, we get, ┘, .

The index n is called the index, and the transition from the function f (x) to the functions f2(x), f3(x),... ≈ iteration. For some classes of functions it is possible to define an index with an arbitrary real and even complex exponent. I. are used to solve various kinds of equations and systems of equations using iterative methods. For more details, see Successive approximation method.

Lit.: Kollatz L., Functional analysis and computational mathematics, trans. from German, M., 1969.

Wikipedia

Iteration (programming)

Iteration in programming, an organization of data processing in which actions are repeated many times without leading to calls to themselves (unlike recursion).

When some action needs to be repeated a large number of times, loops are used in programming. For example, you need to display the text “Hello, World!” 200 times. " Instead of repeating the same text output command 200 times, a loop is often created that repeats 200 times and executes what is written in the body of the loop 200 times. One step of the cycle is called iteration.

Iteration (values)

Iteration- repetition of an action.

• Iteration in programming is an organization of data processing in which actions are repeated many times without causing calls to themselves.
• Iteration in psychiatry is a pathological arousal characterized by rhythmic repetition of a motor act, word or part of a phrase, observed in catatonic syndromes, postencephalitic states, especially with striatal hyperkinesis, with profound dementia, epileptic twilight states, in the process of reverse development of a comatose state of post-traumatic or intoxication genesis.
• Iteration in mathematics is the repeated application of a mathematical operation.
• Iteration in Japanese writing is a sign for doubling a character.
• Iteration - a cycle, the iteration step (or 1st, 2nd, iteration) can be considered one step of the cycle

Examples of the use of the word iteration in literature.

If the concept of the current element is not provided by the iterator, but by the container itself, iteration is forced on the container in the same way that communication fields are forced on objects from the container.

But now iteration turns into a recursion, which can greatly slow down the execution of the program, unless the translator is able to convert the recursion back into iteration.

So it’s difficult to manage two at the same time iterations for one container, but memory and time costs with such an organization iterations close to optimal.

For him, dependence on the implementation that supplies the subjects iterations objects are determined at the time of initialization and can change during program execution.

This causes the following to execute iterations current cycle, which again displays the submenu.

On each iterations cycle, the current time is checked against the assigned time passed from the command line.

In all likelihood, the way we perceive our daily existence and recreate it for each other in stories has more to do with physics iterations, than to ontology as people understand it.

Since the outer loop is set to one iteration, the inner loop becomes the main one.

For example, valid recursive definition schemes made it possible to write a simple iteration for solving systems of linear equations, but what about Zeidelevskaya?

It grows with every nanosecond, with every iteration its endless expansion, but it needs our help to stay healthy.

The theory predicts that after a certain number iterations it will reach critical mass.

It doesn't matter what initial value is entered into the equation - as long as there is enough iterations you end up with the same expression, called an attractor.

For slightly different initial sets after repeated iterations we get sharply different sets.

Use quick prototyping as part of your plans iterations to establish technical requirements for software.

Many lossy algorithms can significantly damage an image within a few minutes. iterations editing.

Repetition, cycle Dictionary of Russian synonyms. iteration noun, number of synonyms: 2 operation (457) ... Synonym dictionary

iteration- — [] iteration Repeated application of a mathematical operation (with changed data) when solving computational problems to gradually approach the desired result (this can be seen in ... ... Technical Translator's Guide

The repeated application of a mathematical operation in a series of similar operations performed to obtain a result. Dictionary of business terms. Akademik.ru. 2001... Dictionary of business terms

- (from Latin iteratio repetition) repeated application of any mathematical operation ... Big Encyclopedic Dictionary

Iteration- (iteration): more than one-time use of a component for various operations... Source: INFORMATION TECHNOLOGY. METHODS AND MEANS OF ENSURING SAFETY. CRITERIA FOR ASSESSING THE SECURITY OF INFORMATION TECHNOLOGIES. PART 1.… … Official terminology

iteration- and, f. iteration f. lat. iterare repeat, renew. mat. The result of using what n. mathematical operation resulting from a series of similar operations. Krysin 1998. Iterated aya, oe. Repeated. Sauer. Lex. SIS 1954: iteration… Historical Dictionary of Gallicisms of the Russian Language

Iteration- repeated application of a mathematical operation (with changed data) when solving computational problems to gradually approach the desired result (this can be seen in the block diagram for calculating the arithmetic mean, see Fig. A.2 to the article... Economic-mathematical dictionary

- (lat. iteratio repetition) mat. the result of using what l. mathematical operation resulting from a series of similar operations. New dictionary of foreign words. by EdwART, 2009. iteration [Dictionary of foreign words of the Russian language

- (from Latin iteratio repetition), repeated application of any mathematical operation. * * * ITERATION ITERATION (from the Latin iteratio repetition), repeated application of any mathematical operation... encyclopedic Dictionary

iteration- iteracija statusas T sritis automatika atitikmenys: engl. iteration vok. Iteration, f rus. iteration, f pranc. itération, f … Automatikos terminų žodynas

Books

• Agile testing. A Practical Guide for Software Testers and Agile Teams, Crispin Lisa, Gregory Janet. Testing is a key component of agile development. The widespread adoption of agile methods has led to the need to place effective testing techniques in the spotlight, and agile…
• Normal families of analytic functions. , Montel P.. Normal families... belong to the pen of the famous French mathematician P. Montel and are a monograph on the theory of normal families, the creator of which is P. Montel, and ...

An iteration is a set period of time within a project during which a stable working version of the product is produced. It comes with installation scripts, accompanying documentation, and other artifacts that are necessary to use this release.

Brief information

A working version of the product allows you to show stakeholders the actual development of the project. During the demonstration, the development team can get feedback on what needs to be done to gain a broader understanding of the needs and how to implement them. The next iteration is based on the previous one. The resulting product is one stage closer to the final one. An iteration is a limited period. In other words, the schedule is quite rigidly fixed. In order to meet this schedule, the content of the time period may change.

Peculiarities

An iteration is a clearly regulated period. Project development has carefully planned goals, and the duration of the time period itself is fixed. When regulating, each iteration sets its own evaluation criteria. At the same time, responsibilities and tasks are clearly distributed among the participants involved in the project. Additionally, a study of objective indicators of project development is carried out. An iteration is a period involving a certain number of rework. It should be said that they are all carried out in a structured way.

Integration

Any simple iteration must consider the likely risks that are important to the project and also implement high-priority components of the work. The result is confidence that each period adds maximum value to stakeholders while reducing uncertainty. Typically, iterative development is combined with continuous or frequent integration. In other words, once the components pass the unit tests, they are integrated into the overall project. Afterwards assembly and testing are carried out. Thus, the capabilities of integrated products increase throughout the iteration relative to the goals that were determined during planning. Regular builds (daily or more frequent) allow you to separate the problems and tasks of integration and testing and distribute them evenly throughout the entire development cycle. Often the reason projects fail is that all the difficulties are discovered at one point in one event at the final stage. In this case, because of a single problem, the entire team stops.

Prospects

Due to the complexity of the software used today, it is not always possible to consistently design, define requirements, test, implement, select an architecture, and perform these and other steps correctly. The iterative solution allows, at the end of each period, to give interested parties access to the project's capabilities. In this case, the team receives feedback quickly and periodically during development. They, in turn, allow improvements to be made and problems to be solved more cost-effectively if they are within the project's time and budget and long before development has progressed far enough that significant modifications may be required. Iteration allows you to get working code. It can be activated, evaluated and adjusted in the direction of project development. Typically the period lasts four weeks. However, there are teams that work for seven days or longer - up to a month and a half.

An iteration is a set of operations that results in the creation of release product: a stable executable version along with the auxiliary elements necessary to work with it. Thus, iteration can be considered as one complete pass through all disciplines, at a minimum, including requirements management, analysis and design, implementation and testing. An iteration can be compared to a small waterfall model project. Please note that evaluation criteria are set separately for each iteration when it is planned. The release will have a planned feature set that can be showcased. The duration of an iteration depends on the size and nature of the project, but in most cases each iterations are performed some product compilations according to the integration build plan for a specific iteration. This approach is a consequence of the application of the principle of continuous integration recommended in the Rational Unified Process (RUP): when ready, autonomously testable components are integrated into the system, and then the system is assembled and tested for correct integration. With this approach, the set of functions of the integrated product expands as the iteration progresses and gradually approaches the tasks set at the iteration planning stage. Each compilation can be considered a miniature iteration, with the only difference being that iterations require different planning and formal evaluation of the results. Some projects make sense to compile the product every day, but such compilations cannot be called iterations in the RUP definition unless it is a miniature project performed by a single programmer. Even small projects with several developers working on them (for example, 5 programmers writing 10,000 lines of code) are very difficult to implement iterations that last less than a week. The reasons for this are outlined in the Recommendation: Software Development Plan section.

Why are iterations needed?

Previously, most projects came down to a one-time sequential implementation of all the prescribed disciplines. This life cycle is called waterfall:

This approach is characterized by the accumulation of a huge number of flaws in the integration area towards the end of the implementation cycle, when the product is first compiled and testing begins. Errors that were not noticed at the stages of analysis, design and implementation emerge, and the project practically stops for a long time, during which errors will be corrected.

A more flexible and less risky approach to development is to iterate across disciplines to better understand the requirements, design a robust architecture, streamline the development process, and conduct multiple implementation cycles as the product becomes more and more complete. This life cycle is called iterative. A one-time execution of a sequence of process disciplines is called iteration.

From a developer's point of view, such a life cycle is a sequence iterations, during which the software is gradually developed. Each iteration ends release executable product. The release may not support all features of the target system, but it is a useful source of information for developers and users. Along with each release, related work products are created: release description, documentation, plans, etc., as well as updated system models.

The main result of the iterative approach is the development and maturation of the previously described work products, as shown in the following diagram.

Evolution of information content at various stages of development.

Small milestone

Each iteration ends with a minor milestone, which verifies that the result of the iteration meets the evaluation criteria established for that particular iteration.