I'm plotting database performance values with the excellent (excellent!) Chart::Strip module.

A problem I have is that I have a group of values, e.g. wait events of different types, sharing a chart. But the typical value for e.g. "Take Lock" is normally an order of magnitude lower than e.g. "Output to network". So I put these two values in two different charts so the scales of the charts are meaningful.

But, let's say that sometimes something happens, and the values for "Take Lock" goes wild. It should now be put in the other chart with "Output to network", because these values are more similar.

I'd like to have two charts, and dynamically chose on which chart to plot the values. Large values go to the "High" chart, and small values go to the "Low" chart. So I need to somehow cluster the values into two groups that are fairly cohesive, so that all the values that end up on one chart get a scale that is relevant.

But, being mathematically challenged, I have no idea whatsoever how to do this :) What's this kind of thing called (to Google for it)? What kind of strategies can I use to try things out? Some kind of statistics thingy?

(My thoughts so far, which may be enough to solve the problem, is to just separate the values over/under the mean. But that may just be naive.)

/J

In reply to [OT] Grouping/clustering of values by jplindstrom

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