Finding patterns in big data with SAS/GRAPH
Data: 30 lug 2012

When working with “big data” you usually have too many points to view in a plot, and end up subsetting or summarizing the data. But now, in SAS 9.3, you have an alternative!


For example, the following scatter plot of 10,000+ points is just a visual “blob”:

But using a new SAS 9.3 feature, alpha-transparency, you can make the plot markers semi-transparent, and “see” the hidden patterns. When multiple markers “stack up” in the same location, their transparent colors “add up” and they become darker.

In this case, I had “hidden” a densely-packed ‘ring’ of points in the data. This pattern is visually obscured when plotted with solid-colored markers (above), but very visible in graph with transparent markers (below):