From Origin 2018, the major and minor radius of the correlation ellipse in Scatter Matrix are exported to the result sheet. No matter you create the Scatter Matrix from Plot: 2D: Scatter Matrix or Statistics: Descriptive Statistics: Correlation Coefficient, you can find the major and minor radius of each correlation ellipse by A and B values in the Parameters column label row of the PlotData worksheet, where A is the major radius and B is the minor radius.