A scatterplot matrix shows a matrix where the lower triangle displays scatterplots of variable pairs, the diagonal displays variable histograms and the upper triangle displays correlations of variable pairs. Also known as a SPLOM.
Requirements
- A series of categorical or numeric variables to use as correlation inputs.
- See Variable Sets for more info on how to set the measurement scale and values for analysis.
Method
- From the toolbar, select Visualization
> Scatter > Scatterplot Matrix.
- Click on the page to place the visualization.
- From the Object Inspector
, go to Data and select variables from the Variables to plot dropdown or drag them from the Data Sources tree into the Variables to plot box.
- Click Calculate.
- OPTIONAL: Variable names - toggle this on to show variable names in the matrix instead of variable labels.
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Missing data: Method for dealing with missing data.
- Error if missing data - An error is returned if any of the data used in the analysis contains missing values.
- Exclude cases with missing data - The analysis is conducted using cases with no missing data. For example, if there are three variables, x, y, and z, and the total sample size is 10, but 5 cases have no data for z, only the 5 cases with complete data are used in the analysis. This is also known as casewise deletion and the complete-case method. It is the default approach in Displayr.
- Use partial data - The analysis is conducted using all the data for each case. For example, in K-Means Cluster Analysis, if there are nine variables in the analysis, and a case only has data for six, then the case is assigned to the most similar cluster based on the data for the six variables.
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Fitted line:
- None - No fitted line is shown in each scatterplot.
- Straight - A line of best fit (from linear regression) is shown in each scatterplot.
- LOESS - A line generated using fitted values from locally weighted polynomial regression is shown in each scatterplot.
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Scatter point modifications:
- None - No modifications.
- Jitter - Add noise to each point so that areas with closely positioned points appear denser.
- Enlarge points with multiple observations - Multiple points with identical positions will appear as an enlarged point. This is the default.
- OPTIONAL: Further visual modifications can be made via the Chart tab in the Object Inspector
. This tab contains options for formatting the text and graphical elements in the chart. It is organized into groups for Correlation (panels in the upper-right triangle), Scatterplots (panels in the lower-left triangle), and Histograms (panels along the diagonal).
Next
How to Create a Correlation Matrix
How to Conduct a Test of Correlation Between Two Variables
How to Create a Table of Coefficients from a Correlation Matrix