Statistics 简明教程

Statistics - Scatterplots

散点图是一种以图形方式显示定量样本变量之间关系的方法。它由 X 轴、Y 轴和一系列点组成，每个点表示数据集中一项观察结果。点的坐标表示其 X 值和 Y 值。

A scatterplot is a graphical way to display the relationship between two quantitative sample variables. It consists of an X axis, a Y axis and a series of dots where each dot represents one observation from a data set. The position of the dot refers to its X and Y values.

scatterplots

Patterns of Data in Scatterplots

散点图用于分析模式，这些模式通常在直线性、斜率和强弱的方面有所不同。

Scatterplots are used to analyze patterns which generally varies on the basis of linearity, slope, and strength.

  1. Linearity - data pattern is either linear/straight or nonlinear/curved.

  2. Slope - direction of change in variable Y with respect to increase in value of variable X. If Y increases with increase in X, slope is positive otherwise slope is negative.

  3. Strength - Degree of spreadness of scatter in the plot. If dots are widely dispersed, the relationship is consider weak. If dot are densed around a line then the relationship is said to be strong.