Further reading
Scientific paper, The potential of parsimonious models for understanding large scale transportation systems and answering big picture questions by Carlos F. Daganzo, Vikash V. Gayah, and Eric J. Gonzales, available here: https://link.springer.com/article/10.1007/s13676-012-0003-z
SAS white paper, Arrays – Data Step Efficiency by Harry Droogendyk, available here: https://support.sas.com/resources/papers/proceedings13/519-2013.pdf
SAS white paper, Programming with the KEEP, RENAME, and DROP Data Set Options by Stephen Philp, available here: https://support.sas.com/resources/papers/proceedings/proceedings/sugi31/248-31.pdf
United States Department of Agriculture Food and Nutrition Service Healthy Eating Index: https://www.fns.usda.gov/healthy-eating-index-support-files-03-04
University of Manitoba's web page, which explains the use of the Charlson Comorbidity Index and how it has been standardized using SAS arrays at the Manitoba Centre...