Publish Time: 2021-09-01 Origin: Site
Data coding is the key to computer processing. Different information records should adopt different codes. A code point can represent an information record In order to be easy to use and easy to remember, it is often necessary to encode the processed objects. It is very important to encode the data with a code that represents a piece of information or a string of data in the management of the computer. It can be convenient to carry out the operation of information classification, checking, total retrieval, etc People can use coding to identify each record, distinguish processing methods, classify and check, so as to overcome the shortcoming of uneven items, save storage space and improve processing speed.
Here is the content list:
The requirements of variable data coding
Purpose of variable data encoding
Uses of variable data encoding
Data coding should follow the systematic standard, practicability, expansion and efficiency. Data coding can establish the internal relationship between data through data coding, which is convenient for computer identification and management. The main data coding in geographic information system is the geographic coding that serves for spatial information analysis, namely the identification of graph points and lines The coding methods based on the location and attributes of the surface or grid include topological coding and coordinate coding. The former is a coding method which represents the adjacent logical relation of spatial data positions. The latter is a measure that represents the position of spatial data in a coordinate system, and may be implicit (for grid data) or explicit.
The main purpose of encoding is to reduce the amount of information, because the data affects the processing efficiency and precision. The inefficiency is mainly due to the large number of characters used for names or descriptions, and much time is spent on reporting, typing, identifying, and understanding. More importantly, there must be enough space for those characters and numbers. This inefficiency has a great impact on manual operation and computer processing. On the other hand, to improve the accuracy of computer processing, it is necessary to standardize the definition of data items. A well-designed coding structure can solve the above problems. For example, a three-digit code, 000-999, uniquely and succinctly identifies 1000 different entries and takes significantly less space than a verbal description of each one.
In addition to improving processing efficiency and accuracy, coding structure can be used to express specific meaning. For example, a person's ID card number can indicate the province, date of birth, gender, etc. The data about this person can be sorted, summarized, counted and analyzed by computer according to the prescribed algorithm.
Encoding is necessary in both offline batch processing and online query systems. The structure of coding may be very complex, but it is very important to realize modern information processing systems.
One of the uses of coding is to formalize how people categorize things. The result of classification is often a tree hierarchy. Different levels of classification correspond to different levels of abstraction. The level of classification from top to bottom corresponds to the level of abstraction from high to low. Classification is also an effective means for people to control complexity. By classifying a large group of things, it is convenient for people to remember, think, discuss and understand things. Therefore, classification has both objectivity and subjectivity. Classification changes as people's needs change, so the codes that formalize classification should also be able to change to accommodate changes in classification.