<P> For a set of data variables (dimensions) X, X,..., X, the scatter plot matrix shows all the pairwise scatter plots of the variables on a single view with multiple scatterplots in a matrix format . For k variables, the scatterplot matrix will contain k rows and k columns . A plot located on the intersection of i - th row and j - th column is a plot of variables X versus X . This means that each row and column is one dimension, and each cell plots a scatterplot of two dimensions . </P> <P> A generalized scatterplot matrix offers a range of displays of paired combinations of categorical and quantitative variables . A mosaic plot, fluctuation diagram, or faceted bar chart may be used to display two categorical variables . Other plots are used for one categorical and one quantitative variables . </P>

Which of these is the main reason for creating a scatterplot between two variables