Table (information)

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Table of contents

1 Tables as visual aids to conveying information 2 Tables as features offered by application programs 3 Tables as techniques used in programming computers 4 Historical relationship to furniture

Tables as visual aids to conveying information

Tables can help present information in ways that highlight its logical structure using the visual structure of the tables. An organized awareness of the differences among various kinds of table can help make effective use of them. The following examples also suggest the breadth of situations where tables may be helpful:

• One-dimensional tables are lists, outlines, or //one-dimensional arrays or vectorss//, such as:
  • a to-do list (in which the visual aid is that the items are in the order they should be done, and/or are crossed off to indicate completion);
  • a military unit's table of organization; and
  • the table of contents of a Wikipedia article.

• Two-dimensional tables, i.e., //matrices or //rectangular grids, such as:
  • a multiplication, addition, or other mathematical table;
  • the table of contents of a book that includes page numbers;
  • a student's weekly class schedule;
  • a day's schedule showing which rooms are in use for which programs of various lengths;
  • a conversion table for any of various purposes; and
  • //A mathematical matrix or 2-dimensional array of numbers or variables.//

• Multi-dimensional tables, //in theory capable of holding any countable// of any comprehensible number of dimensions, and usually using multiple two-dimensional tables to visualize "cross-sections" of tables of larger dimension, as in:
  • tables of census, econometric, or public-opinion-polling data;
  • a timetable for public transport; the number of logical dimensions can vary; it is often four or five: it is represented as a set of two-dimensional tables with two or three parameters (such as line, direction, and possibly part of the week) identifying each; and
  • //A mathematical tensor, representing a (3-D (or more?)) array of numbers.//

• Periodic tables. A periodic table is an array of information where every nth element shares some common characteristic, and so the array is "wrapped around" to form a 2-dimensional table. Examples include:
  • a calendar month page;
  • the Periodic table of elements; and
  • a tide table is a two-dimensional table (the intersection of high and low tide times with a date) usually wrapped into periodic form (a calendar month).

Tables as features offered by application programs

Traditionally, the most familiar media for creating and storing tables have been pen and paper. Given the proliferation of computers at home and in the workplace, computer representations of "paper tables" have become widespread. Common software applications give users the possibility of generating, manipulating, and editing both table data and table formats with ease. Such applications include:

• word processing applications;
• spreadsheet applications;
• presentation software; and
• tables specified in HTML or another markup language.

Tables as techniques used in programming computers

Data tables are used extensively in computers, in forms as diverse as equal-sized and consecutive blocks of memory locations, on one hand, and "scatter-storage" schemes relying on what are more conventionally known as hash functions, on another. Each is a distinct data structure in computer science. Use of tables is more likely to be invisible to anyone but a few colleagues of the programmer, than to improve comprehension of the tables' contents; in many cases, their technical effectiveness would outweigh even loss of comprehensibility.

Examples include:

• all the examples of applications of the n-dimensional array so familiar to computer science students;
• symbol tables;
• inode tables; and
• various forms of table-driven software where the software is controlled from a table, or hardware is relieved, via table-stored data, of some burden of computation.

Historical relationship to furniture

In the medieval counting houses, the tables were covered with a piece of chequered cloth, to count money. Exchequer is an archaic term for the English institution which accounted for money owed to the king. Thus the checkerboard tables of stacks of coins are a concrete realization of this information.