Shanshan Chen

Merging, Binding, Differentiating Datasets

• Merging two data frames with different varibles by IDs

  library(tidyverse)
  COV <- merge(COV1, COV2,by = c("ID","Age","Gender","Race","Events"), all = TRUE) ## overlapping variables are listed in the "by" argument
  

• Binding two data frames with same variables

  library(tidyverse)
  bind_rows(COV1, COV2)
  

• Checking differences between two similar data frames for same IDs

  library(diffdf)
  diffdf(COV1[COV1$ID %in% COV2$ID,], COV2) ## suppose COV1 is a superset of COV2
  

• Joining two data frames with same variables, but missing values appear in different rows for different variables

  library(rqdatatable)
  COVall <- natural_join( COV[COV$ID %in% XC$ID,],XC by = "ID",jointype = "FULL")