Compare matrices to find the differences

Question

I have 2 matrices, I want to compare them (row.name wise) to find the difference.

> head(N1)
              Total_Degree Transitivity Betweenness Closeness         


        

Answer 1

That is a part of the solution, in res you have a data.table to work with for the difference part:

require(data.table)
require(dplyr)

set.seed(2016)
dt1 <- data.table(V1 = c("a", "b", "c", "d"), V2 = rnorm(4))
dt2 <- data.table(V1 = c("c", "d", "e", "f"), V2 = rnorm(4))

# common <- merge(dt1, dt2, by = "V1")[, Unique := "Common"]
# unique1 <- dt1[V1 %nin% dt2[, V1], ][, Unique := "N1"]
# unique2 <- dt2[V1 %nin% dt1[, V1], ][, Unique := "N2"]
# res <- rbind(common, unique1, unique2, fill = TRUE)

Small update after @Cath answer, just for clarity.

allMerged <- merge(dt1, dt2, by = "V1", all = TRUE) %>%
  .[, RowSum := rowSums(.SD, na.rm = TRUE), .SDcols = grep("V2", names(.))] %>%
  .[, Unique := ((is.na(V2.x) + 2*is.na(V2.y)))]

print(allMerged)