Could you please post a sample workbook and describe the results you hope to receive from the macro?

I am guessing that you have a scatter chart (as opposed to line chart). I am also guessing that you want to distinguish points that are clustered as opposed to scattered.

One approach you might use is to establish criteria for clustered points, such as having more than 6 other points within a distance of 10% of square root(X-axis scale^2 + Y--axis scale^2). This criteria assumes that the scale (by which I mean the difference between maximum and minimum scale values on the chart) has comparable values on X-axis and Y-axis.

If X-axis and Y-axis have drastically different scale values, then you might use an alternative criteria, such as more than 6 other points within both 7% of X-axis scale and 7% of Y-axis scale.

The code will be easy once we agree on how to distinguish between clustered and scattered. That said, the number of points on your scatter chart will greatly affect how long it takes to make the calculations. This is because each of the n points on a chart must be compared against all n-1 other points. So the difficulty increases as the square of the number of points on the chart.

Brad