On Fri, 17 Jul 2015, Aaron Mackey wrote:
One immediate question is how independent you believe the 46 components to be, and whether certain components could be reduced or otherwise coordinately-modeled; a heatmap of your 46x46 pairwise correlations should be informative. Also consider log-scaling, especially if some component fractions can be very small/minor components compared to large/major components.
Aaron, Most components are elements spread across the periodic table; the rest are composits such as total dissolved/suspended solids, acid neutralizing capacity, specific conductance, bicarbonate. A heat map will be drawn. Log scaling is the key to working with compositional data. The log-ratios can be calculated using three equations with two being most frequently applied, each depending on the analysis to follow. Thanks, Rich ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
