Topics

SAS programming tasks mapped to R.

SAS task first. The R name follows where there is a close equivalent.

Basics

• Create or change columns DATA step assignment -> mutate
• Keep, drop, and rename columns KEEP / DROP / RENAME -> select / rename
• Keep rows that match a condition WHERE / subsetting IF -> filter
• Conditional values IF-THEN / IFN / IFC -> if_else / case_when
• First non-missing COALESCE / coalescec -> coalesce
• Convert character, numeric, and date PUT / INPUT -> as.character / as.numeric / as.Date

Text

• Extract part of a character value SUBSTR -> substr
• Change text case UPCASE / LOWCASE / PROPCASE -> toupper / tolower / toTitleCase

Dates

• Study day --DY date subtraction
• Partial dates impute year-only or year-month (ADaM)

Combining Data

• Merge on keys MERGE / SQL JOIN -> *_join
• Stack datasets SET -> bind_rows
• Transpose rows and columns PROC TRANSPOSE -> pivot_longer / pivot_wider

Derivations

• Within-subject sequence --SEQ -> row_number
• Last observation before exposure --LOBXFL