2.15:

2.15: 饼形图

JoVE Core
Statistics

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JoVE Core Statistics

Pie Chart

2.14: Pareto Chart

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01:04 min

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April 30, 2023

Overview

A pie chart (or a pie graph) is a circular graphical chart or a pictorial representation of categorical data. It is divided into slices of pie each indicating numerical proportions. It is also used to show the relative sizes of data in a single chart.

In a pie chart, the central angle, the arc length of each slice, and the area are directly proportional to the quantity or percentage it represents. Some real-world examples that can be depicted using pie charts include marks obtained by students in a class, the monthly expenditure of a family, and the cost of construction of a house. With the help of a pie chart, one can easily compare the sum spent on steel, cement, and so on during construction. The actual sum spent on each individual expense can also be computed.

A pie chart's main advantages are that it is simple to use and easy for the audience to quickly analyze and understand information. However, if there is a lot of data, it may become challenging for readers to visualize and assimilate information using a pie chart.

Transcript

考虑一个总结了不同国家/地区 COVID-19 病例发生率的表格。这种具有频率计数的定性数据可以使用饼图表示，饼图是一个圆圈形式的图表，就像饼图一样。

那么，如何将表中的数据转换为饼图呢？

首先，将 A 国的 COVID 病例数除以所有 COVID 病例的总和。将此值乘以 360 度（一整圈的度数），得到相应国家/地区的扇形角。

同样，计算其他国家/地区的扇区角。使用这些扇形角，将圆划分为与给定类别数相等的切片。

请注意，COVID 病例的百分比频率也对应于其切片的大小。在这里，行业最大的国家 E 表示 COVID 病例的百分比最高。相比之下，扇区角最小的国家 F 显示的病例百分比最小。

Key Terms and definitions

Pie Chart - A circular graphical representation of categorical data and proportions.
Sectors - The individual slices of a pie chart representing specific data.
Central Angle - In pie chart, an angle proportional to the represented data.
Categorical Data - Information that can be categorised into groups; often represented by pie charts.
Relative Frequency - The proportion of the total data value that an individual category represents.

Learning Objectives

Define Pie Chart – Understand its role in data visualization (e.g., pie chart).
Contrast Piechart and Bar Graph– Highlight key differences (e.g., categorical vs quantative data).
Explore Pie Chart Examples – Understand its usage in real-life scenarios (e.g., family expenses).
Explain Central Angle - Its connection to the data portion in a pie chart.
Apply Pie Charts in Context – Methodology for creating pie charts using raw data.

Questions that this video will help you answer

What is a pie chart and how does it represent categorical data?
How is central angle used in the construction of pie charts?
What are the advantages of using pie charts in data visualization?

This video is also useful for

Students – It assists in understanding data analysis and interpretation using pie charts.
Educators – Provides a comprehensive understanding of pie charts for teaching data visualization.
Researchers – Pie charts are vital for representing categorical data in research.
Statistics Enthusiasts – Offers a deeper understanding of data representation and analysis.

Tags

饼图圆图分类数据比例相对大小圆心角弧长面积支出建筑成本数据可视化信息分析