# Do “splits” in scatterplots indicate anything?

## Background

I'm exploring how 7 system parameters spanning mechanical, electrical, and physical (size) properties are related. I gathered the 7 specs of 36 different systems, and I plotted every parameter combination to see what, if any, correlations existed.

• Each column has the same x-axis parameter as identified in the bottom row
• Each row has the same y-axis parameter as identified in the first column

## Discussion

Some of the plots verify known relations: I knew beforehand that parameter 3 & 4's are positively correlated and parameter's 2 & 7's are inversely correlated.

I also know that I have an incomplete picture. For example, parameter 1 is a product of parameter 3 and two other parameters that I don't have data for. One (or potentially both!) of these unknown parameters significantly affects parameter 2. I don't know how, but I know the correlation exists.

## Questions

I'm curious if the mid-trend "splits"/divergences in some plots--eg: p5 vs p4, p5 vs p6, p7 vs p6--are the effects of those unknown parameters.

1. What, if anything, do these splits indicate?
2. What are some additional tests I can run to reveal more concrete info?

PS: Please let me know how I can improve my chart!

As Nuclear Wang and DWin suggested, I investigate my data for subgroups. I also added data from another discrete variable, so my total number of parameters is 8.

Parameters 5 and 6 (diameter and length) are both volumetric specs, so I divided all points based on their D/L ratio. This actually resolved most of the "divergences"!

• The flat and wide systems (D/L > 1) are blue
• The long and skinny systems (D/L <= 1) are orange

pairs(  data , bg= rainbow(10)[parm3], other parameters)