A scatter diagram, also called a scatterplot or a scatter plot, is a visualization of the relationship between two variables measured on the same set of individuals.
Scatter diagrams for lists of data 
, 
, ... can be generated with the Wolfram
Language using ListPlot[
x1, y1
, 
x2,
y2
,
...
].
A scatter diagram makes it particularly easy to spot trends and correlations between the two variables. For example, the scatter diagram illustrated above plots wine consumption (in liters of alcohol from wine per person per year) against deaths from heart disease (in deaths per 100,000 people) for 19 developed nations (Moore and McCabe 1999, Ex. 2.5)
There is clearly and inverse relationship between these two variables. Once such a relationship has been found, linear regression can be used to find curves of best fit. The graph above shows the same scatter diagram as above together with a line of best fit.
