Working with Scatter Plots :: SAS(R) Visual Analytics 5.2: User's Guide

About Scatter Plots

A scatter plot represents the values of measures by using markers. When you assign more than two measures, the visualization displays a scatter plot matrix. A scatter plot matrix is a series of scatter plots that displays every possible pairing of the measures that are assigned to the visualization.

If you create a scatter plot that has a very large number of points, then the plot is rendered either as a heat map (for two measures) or as a correlation matrix for three or more measures.

Specify Properties for a Scatter Plot

On the Properties tab, you can specify the following options:

Name

specifies the name of the visualization.

Graph title

specifies the title that appears above the graph.

Note: The Graph title is disabled if you select Generate graph titles.

Generate graph titles

specifies that the graph title is generated automatically based on the data items in the visualization.

Show grid lines

displays grid lines for each tick on the plot axes.

Marker size

specifies the size of each marker in pixels.

Note: Sizes below 4 pixels are not supported when your scatter plot is grouped.

Data Roles for a Scatter Plot

The basic data role for a scatter plot is the measures. You can assign any number of measures.

In addition to the measures, you can assign a Group variable. The group variable groups the data according to the values of the category data item that you assign. A separate set of scatter points is created for each value of the group variable.

Applying Data Analysis

About Data Analysis

For scatter plots, you can apply the following data analyses:

Correlation

identifies the degree of statistical correlation between the variables in the scatter plot.

Regression

plots a model of the relationship between the variables in the scatter plot.

Both correlation and regression analysis are applied together when you enable correlation analysis.

Enable Data Analysis

To apply data analysis, select Options

Show Correlation or click Correlation from the visualization toolbar.

For a single scatter plot, the degree of correlation is indicated by a text label in the legend below the plot. To see additional information about the correlation results, click About these correlation results

.

For a grouped scatter plot, the degree of correlation for each plot is indicated by the color of the border around the plot. To see additional information about the correlation results for all of the plots, click About these correlation results

.

By default, a regression fit is applied to your plot when you enable correlation analysis. The regression fit appears as a red line. To see additional information about the regression results, click About these regression results

in the legend.