The Full Wiki

Chart: Wikis

  
  

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

Encyclopedia

From Wikipedia, the free encyclopedia

A chart is a visual representation of data, in which "the data are represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart".[1] A chart can represent tabular numeric data, functions or some kinds of qualitative structures.

Contents

Overview

The term "chart" as a visual representation of data has multiple meanings.

  • A data chart is a type of diagram or graph, that organizes and represents a set of numerical or qualitative data.
  • Maps that are adorned with extra information for some specific purpose are often known as charts, such as a nautical chart or aeronautical chart.
  • Other domain specific constructs are sometimes called charts, such as the chord chart in music notation or a record chart for album popularity.

Charts are often used to ease understanding of large quantities of data and the relationships between parts of the data. Charts can usually be read more quickly than the raw data that they are produced from. They are used in a wide variety of fields, and can be created by hand (often on graph paper) or by computer using a charting application. Certain types of charts are more useful for presenting a given data set than others. For example, data that presents percentages in different groups (such as "satisfied, not satisfied, unsure") are often displayed in a pie chart, but may be more easily understood when presented in a horizontal bar chart.[citation needed] On the other hand, data that represents numbers that change over a period of time (such as "annual revenue from 1990 to 2000") might be best shown as a line chart.

Features of a chart

A chart can take a large variety of forms, however there are common features that provide the chart with its ability to extract meaning from data.

Typically a chart is graphical, containing very little text, since humans are generally able to infer meaning from pictures quicker than from text. One of the more important uses of text in a graph is in the title. A graph's title usually appears above the main graphic and provides a succinct description of what the data in the graph refers to.

Dimensions in the data are often displayed on axes. If a horizontal and a vertical axis are used, they are usually referred to as the x-axis and y-axis respectively. Each axis will have a scale, denoted by periodic graduations and usually accompanied by numerical or categorical indications. Each axis will typically also have a label displayed outside or beside it, briefly describing the dimension represented. If the scale is numerical, the label will often be suffixed with the unit of that scale in parentheses. For example, "Distance travelled (m)" is a typical x-axis label and would mean that the distance travelled in metres is related to the horizontal position of the data.

Within the graph a grid of lines may appear to aid in the visual alignment of data. The grid can be enhanced by visually emphasizing the lines at regular or significant graduations. The emphasized lines are then called major grid lines and the rest of the grid lines are minor grid lines.

The data of a chart can appear in all manner of formats, with or without individual labels. It may appear as dots or shapes, connected or unconnected, and in any combination of colors and patterns. Inferences or points of interest can be overlayed directly on the graph to further aid information extraction.

When the data appearing in a chart contains multiple variables, the chart may include a legend. A legend contains a list of the variables appearing in the chart and an example of their appearance. This information allows the data from each variable to be identified in the chart.

Types of charts

Common charts

Four of the most common charts are:

This gallery shows:

  • A histogram typically shows the quantity of points that fall within various numeric ranges (or bins).
  • A bar chart uses bars to show frequencies or values for different categories.
  • A pie chart shows percentage values as a slice of a pie.
  • A line chart is a two-dimensional scatterplot of ordered observations where the observations are connected following their order.

Other common charts are:

Less-common charts

Examples of less common charts are:

This gallery shows:

  • A bubble chart is a two-dimensional scatterplot where a third variable is represented by the size of the points.
  • A Polar area diagram, sometimes called a Coxcomb chart developed by Florence Nightingale is an enhanced form of pie chart.
  • A radar chart or "spider chart" is a two-dimensional chart of three or more quantitative variables represented on axes starting from the same point.
  • A waterfall chart also known as a "Walk" chart, is a special type of floating-column chart.
  • A Tree Map where the areas of the rectangles correspond to values. Other dimensions can be represented with colour or hue.

Field-specific charts

Some types of charts have specific uses in a certain field

This gallery shows:

  • Stock market prices are often depicted with a open-high-low-close chart with a traditional bar chart of volume at the bottom.
  • Candlestick charts are another type of bar chart used to describe price movements of an equity over time.
  • A Kagi chart is a time-independent stock tracking chart that attempts to minimise noise.
  • Alternatively, where less detail is required and chart size is paramount, a Sparkline may be used.

Other examples:

  • Interest rates, temperatures, etc., at the close of the period are plotted with a line chart.
  • Project planners use a Gantt chart to show the timing of tasks as they occur over time.

Well-known named charts

Some of the better-known named charts are:

Some specific charts have become well known by effectively explaining a phenomenon or idea.

Other charts

There are dozens of other types of charts. Here are some of them:

Common plots

See also

References

  1. ^ Cary Jensen, Loy Anderson (1992). Harvard graphics 3: the complete reference. Osborne McGraw-Hill ISBN 0078817498 p.413

1911 encyclopedia

Up to date as of January 14, 2010
(Redirected to Database error article)

From LoveToKnow 1911

(There is currently no text in this page)


Simple English

.]] A chart or graph is an image which summarizes data and presents it in an easy to understand way. Charts are often used to make it easier to understand the relationships of different aspects of the data. It is easier to read a chart than the raw data.

Types of charts









Got something to say? Make a comment.
Your name
Your email address
Message