Hi, I have two questions about options for panel, upper.panel, lower.panel in pairs(). 1. I see examples using panel.smooth, panel.corr, panel.hist. Are there any plots that can be used here? 2. Can we have different plots in upper diagonal? For example, in a matrix of scatterplots, I want to know if we can have a scatter plot for an element (1,2) and then one smooth plot for an element (1,3). Thanks.