# Researching non-linear correlations through scatter matrix

I am trying to understand the correlations among three explanatory variables of commercials and response variable sales through the scatter plot matrix. It seems like there are non linear relationships.

Can anyone please show me some insights more specifically which possible regression models should be applied?

• The R function to do this ranking of some vector of data x is ecdf(x)(x). Plot that against ecdf(y)(y). This has the nice property of removing the effects of the marginal variables, which can appear to be part of the dependence structure.