To this aim, we evaluated the statistical properties of joint association analysis of two correlated quantitative traits in samples of unrelated subjects through simulation studies using the seemingly ...

You can use the values from the Density column of this table with PROC GCONTOUR to plot the 1, 5, 10, 50, 90, 95, and 99 percent levels of the density: proc gcontour data=o1; plot y*x=density / ...